| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1426.1 | Electric Flight is Alive!!!! | UNYEM::BLUMJ | | Wed May 20 1992 12:45 | 38 |
| Alright electric flight interest is still alive!
Hartmut, I have completed and flown the Multiplex Fiesta 4 times now
and am very happy with it. Very glad I did not sell it, its a great
glider! The computer radio I purchased solved the tricky aileron
linkage problem and it is now an easy ship to rig and fly - no bad
habits. I am flying it with the stabs turned upside down(ie non-
lifting).
I am also flying my Robbe ARCUS on 10 cells and really love it.
I have been debating over buying the Graupner Race Rat as a home for
the ASTRO 05 FAI that came out of my wrecked UHU. I saw 7-cell pylon
racers last year at the KRC meet and I was really impressed. There
is a California design called the Caddy Cat which is all composite
construction and really flew fast. Specs are about the same as the
Race RAT.
Are these things really hard to fly? What prop are you using on your
Race Cat? Is the wing built up or foam? What kind of run time are you
getting?
Have you seen the 7-cell flying wing Urs Leodolter currently is flying
in 7-cell pylon- what a neat looking ship.
Please let us(me- I think electric is dead in this conference) know
what is going on in Europe with Electrics.
The plan for the Caddy Cat is available through the US magazine Model
Airplane News if you are interested. This ship has one most of the
USA pylon meets.
Thanks for the info, please let us know about further flights with the
Race Rat.
Regards,
Jim
|
| 1426.2 | No hard data on RACE CAT yet (happy I took it home in one piece) | KBOMFG::KLINGENBERG | | Wed May 20 1992 16:14 | 44 |
| Hi Jim!
I'm not too familiar with what is going on in the scene, but I'll try
to quote a little from magazines and memory.
With my RACE CAT, I never intended to do serious contests. I just
wanted a simple hot electric plane. And I decided not to buy the
GRAUPNER RACE RAT since I think it's way too expensive for what is in
the box and I wanted to fly mine with 6 cells. I have 4 6-cell packs
from the UHU, FIESTA (2x), Kormoran etc. and I wanted to stick with
them. I know that the RACE RAT can be flown on 6 cells as well, but I
guess a 20% smaller plane is faster. The kit for the RACE RAT costs DM
169.- these days, has a (heavy) plastic fuse and a partly sheeted wing.
The wood for my RACE CAT (full wood construction, fully sheeted
built-up wing costed around DM 20.-. I use the complete unit GRAUPNER
sells for the RACE RAT with the SPEED 500 BB RACE motor and the 6x6"
folding prop. I was warned that the RACE RAT with this motor is not
able to fly the 4 minute pylon runs, but I suspect this is with 7 cells
(higher current/less runtime). I don't care about contests (yet). For
contests, GRAUPNER now has special SPEED 500 COMPETITION motors, new
non-folding props and very good (true) spinners. I'm not sure yet about
the runtime I get on my RACE CAT. Yesterday, the battery was not in
good condition (not used/cycled for 6+ weeks), but it's duration was
still longer than that of my nerves... I was still a little shaky when
I went to bed... I'll let you know more about flight characteristics
when I have flown it under more calm conditions. One important thing is
for sure: You gotta react fast. But it seems it can slow down okay
(when it's not so gusty and the control throws are right). The building
instructions said that if you can fly a trainer, you can fly the RACE
CAT. I'm not yet sure whether I can second that.
I'm not really familiar with Urs Leodolters pylon racer. I recall a
picture of a pylon flying wing form Werner Dettweiler. It looks like a
RACE RAT/CAT without tail and is called VIPER. Had expected it in this
year's GRAUPNER news, but it's not there.
Now that this note (and at least your interest) exists, I promise to
keep you posted on any news I get aware of. But I don't think I'll get
deeper in the pylon racers. I like to have this one and like others
styles of planes as well (my favorite currently is the E-FIESTA). So
the Caddy Cat is not especially of interest to me right now, thanks.
Best regards,
Hartmut
|
| 1426.3 | Did you hear about 400 pylon? | KBOMFG::KLINGENBERG | | Wed May 20 1992 16:19 | 7 |
| Now that I think of it: the current trend seems to be even smaller
pylon racers, based on GRAUPNERs SPEED 400 motor (around DM 10.-/$ 6.-)
Their wingspan is about 600 mm (<24"), often with V-tail. I'll try to
dig up some more details at home if you're interested.
Best regards,
Hartmut
|
| 1426.4 | More questions | UNYEM::BLUMJ | | Wed May 20 1992 16:38 | 18 |
| Hartmut,
Do you know anything about the Robbe Micro Racer? This is
available in USA for $89 vs. $99 for the Graupner Racr Rat. The
advertised weight for the Race Rat is 32 oz. on 7 cells. Also
have you ever seen or heard about the Robbe Tangens electric glider?
Robbe recently reduced the prices of their kits in the USA and they are
competitively priced.
Also do you have experience or opinions on Keller and Graupner Ultra
motors, especially how they compare in performance to Astro Flight
motors. I am debating replacing the Astro FAI 015 in my Arcus with
a Graupner Ultra 900. Due to the high cost($227), I would really
want to see a performance boost.
Thanks,
Jim
|
| 1426.5 | Some answers | KBOMFG::KLINGENBERG | | Thu May 21 1992 11:26 | 46 |
| 1426.6 | More F3E Discussion | UNYEM::BLUMJ | | Thu May 21 1992 13:14 | 60 |
| Hartmut,
Thanks for the speedy reply. I really wish some of these
magazines would start testing motors with a range of the popular
props and publish the static thrust and current draw.
The Astro 015 FAI(10 cell competition motor) I am using in my ARCUS
is available for $99 in the USA. On the bench with an Aeronaut 9.5x5
carbon fiber prop it drew about 28 AMPS. The climb is pretty good
(all up weight of the ARCUS is 64 oz.). I am looking for spectacular
climb, however.
The Graupner Ultra 900 is available from Hobby Lobby for $227 - over
twice as expensive as the ASTRO 015. I have heard good things about
these motors and their ability to spin larger props. The 9.5x5 is
the maximum that should be used with the ASTRO 015.
The Keller 50/4 is also available in the USA from ROBBE international
for $234 - again much more than the ASTRO 015.
I would really like to hear someone who has experience with these
motors before I spend the money. Model Airplane News recently tested
the Graupner Cherry and raved about the performance of the Graupner
Ultra 900 vs. the Speed 700. They claimed a 45 degree inverted
climbout was possible(the all-up weight of the Cherry tested was 64
oz).
The conclusions drawn in a recent article of the British Electric Flyers
Association magazine is that a competitive 10 cell F3E ship currently
weighs 60 oz. and is powered by a Keller 70/4 or equivalent motor
drawing between 40-50 amps.
In the USA, Weston Aerodesign has taken a different approach to their
10 cell F3E offering. The WACO 10-550 as it is known is totally
constructed of Kevlar. The fuse is 100% kevlar and the wings are
kevlar vacuum bagged over grey foam. It is a V-tail, with 74" span
and 550 sq in wing area. The advertised weight of the airframe is
15 oz! The advertised all-up weight with ASTRO 015 FAI and 10 cells
is 42 oz. Vertical climb is claimed as well as level speed of over 100
mph. Like with the rest of his designs(Magic, Merlin, etc) Weston is
believes in light weight and all composite construction. The kit is
available for $99, but you must have vacuum bagging skills. A
completely built version sells for $395. Mr Weston claims this ship
flys circles around the Aeronaut Sunfly(106 oz on 16 cells) and other
"heavy" designs.
Well we now have two distinctly different viewpoints - the "heavy"
design with "heavy" powerful Keller or equivalent motors and Mr
Weston's light designs with light motors.
Is 10 cell F3E popular in Germany?
I live in Rochester, New York and would certainly be interested in
getting a deal on an Ultra motor. I believe the cost for a bank
draft in dm is at least $15(you don't take Visa do you). Let me
know if the cost is advantageous.
Thanks,
Jim
|
| 1426.7 | exchange products - just a thought | HANNAH::REITH | Jim HANNAH:: Reith DSG1/2E6 235-8039 | Thu May 21 1992 13:32 | 5 |
| Sounds like the Astro stuff is much more expensive in Germany. Maybe you can
do an exchange of products of similar value? If you can get the Astro stuff
for less that the Keller and Hartmut can get the Keller for less than the
Astro... Sending an engine back requires no monetary exchange rates. If Hartmut
doesn't need an Astro, perhaps someone else in his area does.
|
| 1426.8 | Ask Ed for 70/4 data and experience | KBOMFG::KLINGENBERG | | Thu May 21 1992 14:12 | 26 |
| Jim,
the Keller 70/4 is one of the best motors for 10-cel F3E ships as far
as I know. For details, please ask Ed. I sent him one last Christmas,
and he claims to get at least 15 seconds vertical climb with the ship
he built around it (don't know data like weight etc.).
Yes, 10 cell F3E is becoming popular here as well. I need to check, I
think GRAUPNER even optimized an ULTRA motor for this class as well.
I can try to find a mailorder house for you that takes VISA (I don't,
and our local hobby shop doesn't either). But maybe we can make
something up when I find someone to carry the motor. If you could
arrange a meet or maybe send the money to someone in SHR, there is
probably a simple solution.
I'm off to the hobby shop now (looking for a reward for a successfully
closed project). Talk to you tomorrow.
Best regards,
Hartmut
P.S.: No, I'm currently not interested in an ASTRO motor - unless I
come home tonight with a plane that could use one :-) But then there is
still the radio that a colleague is interested in etc. We'll definately
find a way to make a deal.
|
| 1426.9 | Didn't buy anything last night | KBOMFG::KLINGENBERG | | Fri May 22 1992 12:25 | 26 |
| I didn't buy a plane last night. Still not sure what I want. The shop
currently has the Solar-UHU on sale (kit with solar cells DM 360.-
instead of DM 498,-) and it's itching me to try that technology, but
it's still a lot of money (400 + DM with motor) and you can get really nice
stuff for the money (Blue Airlines Blue Filou or Simprop Skyracer or
GRAUPNER Chili or computer radio or or or). With the Solar UHU, it's
definately the cheapest and easiest way to get into solar flight, and
it is much more of a floater than the Elektro-UHU. The current it takes
during climb is about half (9.5 A), that gives significantly extended
flights. But the solar cell current is around 1 A, so you still need 9
times as much charging (soaring) time as power (climbing) time. This
will only work out on thermally active days. And then again, on those
days a nice thermal ship would fly just as well for half the money...
I called a guy last night that had an ad in one of last months
magazines. He offered a nice quick-charger that I'd like to have, but
it's gone (when I finally start to read the ads...). But he still has a
Keller 70/4, new in box, for DM 270.- I really considered building a
plane around it, but I decided that the fast RACE CAT is currently
enough for me in that direction. I would need a 60+ A controller and
this and that and - naaahhh, not now. Gotta save some money for the
charger and the radio I've been dreaming of. Jim, do you want me to get
the motor motor for you?
Best regards,
Hartmut
|
| 1426.10 | Micro Racer is overpriced | KBOMFG::KLINGENBERG | | Fri May 22 1992 14:43 | 17 |
| Jim,
I did have the Micro-Racer kit in my hands last night. I was wrong - it
does look nice, but I think if the RACE RAT is overpriced, the
Micro-Racer is even more so. It doesn't even have a plastic fuse, it's
a rather small box of wood. The box costs here around DM 100.-, I would
assume that the wood is worth around DM 20.- (with some of it possibly
readily available in your shop). The wingspan is smaller than the
GRAUPNER RACE RAT and the same as of my RACE CAT.
I would recommend to build a plane like this from scratch. There are
probably plans around in the US as well. If you are interested
especially in the RACE CAT, I can send you copies of the plan. Just let
me know.
Best regards,
Hartmut
|
| 1426.11 | New Ultra on the way | UNYEM::BLUMJ | | Tue May 26 1992 13:10 | 33 |
| Hartmut,
I took Friday off(5/22/92) to "tweak" my ARCUS for the electric
funfly I was going to on Saturday. I had only five flights on the
ARCUS and wanted to get a few more before flying it in front of a lot
of people. Well wouldn't you know it, on the first flight I had a
slightly hard landing, and I mean not bad at all, when I picked the
ship up I noticed the ASTRO 015 shaft was bent. I was not too happy
because this landing was not too bad(stalled at about 2 ft. into high
grass). I immediately went home and ordered a Graupner Ultra 900 from
Hobby Lobby($227).
I now will be able to provide a "real life" comparision between the
Ultra 900 and Astro 015 FAI. If the shafts on the ASTRO motors are
going to bend this easily I am not sure they are that great a value.
The Graupner motor has a 5mm shaft vs. a 5/32" shaft for the ASTRO, I
will be curious to see how it holds up.
Based on a test of this motor in a Graupner Cherry II, I will be using
a Graupner 9x7 prop. This combination on 12 cells reportedly gave
53 oz. of thrust with a current draw of 43 amps.
I was running the Astro 015 FAI with a 9.5x5 carbon Aeronaut which
resulted in 28 amps draw and good but not spectacular climb.
I am going to the international scale glider and Power scale Slope
funfly being held at Kiona Butte in the State of Washington. So
the Arcus will not fly with the new motor for 2 weeks.
Regards,
Jim
|
| 1426.12 | Nurnberg Toy Fair | UNYEM::BLUMJ | | Fri Jun 05 1992 13:01 | 7 |
| I just saw the reviews of the Nurnberg Toy Fair and two ships caught
my attention - The Graupner New Match and Robbe Calibra. Any opinions
on these models?
Thanks,
Jim
|
| 1426.13 | Only reviews so far... | KBOMFG::KLINGENBERG | | Fri Jun 05 1992 15:00 | 33 |
| Jim,
the only opinion I have so far is from the review of my favorite
magazine 'Aufwind' (Thermal). Aufwind is a modellers magazine here in
Germany that exclusively covers the areas I'm interested in: gliders,
electrics and experimentals. I like it a lot.
The Robbe Calibra is considered to directly attack Graupner's Chili.
Since the Chili is a nice model, but not really competetive (as Ed
Siegmann says who must know), I assume this is true for the Calibra as
well. I don't have the specs handy, but Ed says if it's over 2 kg, it's
not that great. Still a nice looking ship, if you're not really into
F3E competition. I've already seen a kit at the local hobby shop (the
normal Calibra), but didn't take a close look at it. I might if you're
seriously interested. Tell me what to look out for. (Normal Calibra
means there is a Calibra-pro as well with a nosecone instead of a
conventional fuselage).
The GRAUPNER New Match is considered to be another trendsetter from
Werner Dettweiler's drawing board. It's probably what you dreamed of
for a long time: A poor man's F3E. It's a 7-cell hotliner and high on
the wishlist of the magazine's columnist. I've seen a picture of
Dettweiler attending a meeting with it. He uses 8 cells in his. I
assume to see some at the fields as soon as kits are available.
Fuselage looks very similar and probably is the same as the Solar-UHU
(same heavy material as Elektro-UHU, Cherry, Chili etc.). BTW, the
Chili is available with an Epoxy fuse now. I wonder when they'll have
epoxy fiberglass fuses for the UHU, the Solar-UHU, RACE RAT etc.
Does this help to plan any future projects :-)
Best regards,
Hartmut
|
| 1426.14 | Calibra on order | UNYEM::BLUMJ | | Fri Jun 05 1992 18:01 | 15 |
| Well I called Robbe Modelsport USA just to see if they had any plans
to carry the Calibra. As luck would have it they have them in stock
and on sale for $149, no less. So I ordered one. This electric
flight has become addicting and very expensive. I wanted a second
model to fly while the ARCUS is recharging. This must be my last for
the rest of the year. The Calibra is 2.1 meter employing the HQ 1.5/9
airfoil and is designed for 10-20 cells. The elevator servo is in the
fin- which is why I bought it(I know of no other USA available model
which allows this without modification.) The English publication
"Slient Flight" describes the Calibra as follows - "This should be a
pretty wicked model." I'll report when its built.
Regards,
Jim
|
| 1426.15 | Calibra kit review | UNYEM::BLUMJ | | Thu Jun 11 1992 12:58 | 18 |
| The Robbe Calibra Kit came last night($149). It is a nice kit with
very few parts to assemble. The presheeted obechi covered wings
come with the aileron servo wells predrilled, and the ailerons
partially precut. The controls are ailerons, elevator, and motor
control. The elevator servo is mounted in the fin. Up to 20
Nicads will fit in this fuselage which has no formers or other
obstructions.
The kit is not as nice as the ARCUS kit which had a beautiful
preformed wingmount and tailplane mount. The Calibra kit provides
light ply and you are instructed to fabricate these parts yourself.
Tentative plans for power are an ASTRO 40 FAI on 20 cells, spinning
a Fruedenthaler 10.5x6 prop. I will report how it flys.
Regards,
Jim
|
| 1426.16 | RACE CAT rekitted | KBOMFG::KLINGENBERG | | Thu Jun 11 1992 13:48 | 36 |
| Congratulations on your new kit, Jim! Have fun building and flying it!
I hope to receive your motor soon, didn't hear anything yet. But with
the German Post, it can take some time...
I have a new kit as well - the RACE CAT :-( I rekitted it (partly)
Tuesday night. We went flying (Bernd and me) pretty late when the
breeze had calmed down. When I arrived at the field, I found that the
fuselage had flown around in the trunk and the elevator pushrod ripped
loose. I should have known better by then, but Bernd did me the favor,
went home and picked up some CYA and tape for me to repair it (I had
mine in the shop), and shortly later, the RACE CAT was ready to fly. I
had a nice flight, without the gusts and with significantly reduced
throws it flew very predictable. No bad habits during stalls, and I
tried the first loopings and the first roll. But on landing it's very
hot due to the high wing loading. The glide angle is incredible,
however.
Then came the second flight. As good as the first one. Visibility is
great due to the colour scheme with black and neon red. About 2 minutes
into the flight there was a strange noise and seconds later I saw
something flying away from the plane. Seemed to be the prop or so. I
immediately stopped the motor and set up for a dead stick landing. Due
to the good glide angle, it went far down the meadow (we weren't at the
regular flying field) and when it finally sttled down, it jumped up
again and cartwheeled. Turned out that the wing is fine, but the fuse
is torn apart by the masses of the motor and the battery. Will be no
big deal to fix, and I'll probably reinforce the fuse with a little
glass and/or carbon rovings. The part that flew off was the sinner end
cap, and some boys out of the village nearby who were watching our
flying paid attention very well AND FOUND IT (including the M3 screw)!
So no big bucks damage, just some work (hope to do about half of it
tonight.
Best regards,
Hartmut
|
| 1426.17 | RACE CAT fuselage is back together again | KBOMFG::KLINGENBERG | | Fri Jun 12 1992 12:15 | 12 |
| Re. typos in my last reply: Of course, the plane settled down or tried
to do so (not sttled), and closer examination revealed that the sinner
was still on the tx (although redeemed through the blood of Jesus), and
it was the spinner end cap that flew away. Oh well...
The fuselage is back together already (that's a nice feature of small
planes). One more evening for sanding and glassing and another one for
sanding and covering will hopefully have the RACE CAT operational
again.
Best regards,
Hartmut
|
| 1426.18 | Horten twin ducted fan model | UNYEM::BLUMJ | | Mon Jun 22 1992 14:12 | 21 |
| In the new Model Airplane News a picture of Keith Shaw's(electric
wizard from Ann Arbor, Michigan) new project was shown. It is 62"
wingspan model of a 1944 Horten flying wing which was rumored to be
powered by twin Jet engines.
Keith's model weighs 88 oz. which results in a wing loading of 17oz./
sq. ft. It is a twin ducted fan design powered by two Astro 05
motors spinning homemade fans at 28,500 rpm. The article states
Keith has bee experimenting with electric fans for 5 years, and this
project is the culmination of that work. The thrust produced is
22 oz.(it did not say if that was per unit or the combined thrust of
the two units). Keith estimates that speeds up to 100 mph will be
possible for the model.
The picture really looked great. No other details( whether the motors
were ferrite or cobalt, # of cells, etc) were given. Hopefully he
will have it flying for this year's KRC meet in September.
Regards,
Jim
|
| 1426.19 | I saw an Ariane fly - incredible! | KBOMFG::KLINGENBERG | | Mon Jun 22 1992 14:39 | 23 |
| 1426.20 | F3e and other thoughts | UNYEM::BLUMJ | | Mon Jun 22 1992 17:41 | 35 |
| Hartmut,
My reaction was identical to yours when I saw Steve
Neu's(finished 9th in 1990 World Championships) F3E ship fly
at the KRC meet. He had a minute of runtime available from
27 900mah cells. The ship had a climb rate of over 6000 ft.
per minute.
After seeing this ship fly, I really wanted to build an F3E type
glider. And I have been very broke financially ever since! In
truth it is a lot of fun and combines the best of gliding and
powered flight.
For what its worth Weston Aerodesign is marketing a 10 cell f3e
ship utilizing kevlar and foam construction. The all up weight
of the airframe is advertised at 15 oz. This ship is capable of
going vertical on 10 cells. Weston told me over the phone that
it has been clocked at 126 mph with 14 cells and a heavy motor.
The kit is only $99 but requires vacuum bagging of the wing and
tail surfaces. A kit with prebagged wing is offered for $229 and
a totally built kit is available for $395. Mr. weston claims
an all-up weight of 42 oz. with an Astro 015 on 10 cells. It uses
a cheap on/off switch because the voltage is low.
This might be the ultimate poor man's F3E ship. I ordered my Robbe
Calibra the day before the Weston Catalog arrived, otherwise, I
probably would have ordered the prebagged wing version.
I think if more people were exposed to f3e, it would catch on.
Regards,
Jim
|
| 1426.21 | ARCUS debut@ local funfly | UNYEM::BLUMJ | | Mon Jun 29 1992 13:35 | 39 |
| This weekend I participated in a funfly with my Robbe Arcus. The
Arcus was the only electric ship at the meet(there were about 100
airplanes, I would guess).
Due to light a breeze, the performance of the ARCUS was spectacular.
The climbout on the Ultra 900 with 10 900mah cells turning a Graupner
10x6 prop was real good.
Fortunately there was good thermal activity over the field during
my second flight and I was able to show what a high performance
electric sailplane can do. After an initial climbout to about
500 ft. I did a high speed low level pass. The subsequent climbout
only required about 15 seconds of motor run to get into "thermal
country" where I gracefully circled to speck out height. This
altitude was then used for another high speed pass. I was able
to do this several times.
Many participants had never seen this type of performance from an
electric and were quite impressed. In fact people were calling
it "the rocket" because of the impressive climb which was better than
90% of the gas powered ships. What they didn't realize is my ARCUS
only has 1/3 the performance of a truly high performance F3E ship!
I'm hoping my Robbe Calibra will get to about 1/2 the performance of
a world class f3e ship.
I am just learning how to do rolls and inverted flight with the ARCUS
which is very graceful. I hope to master high speed inverted flight
transitioning to inverted power climbout this summer.
The ARCUS with the above mentioned power setup is a winner and will
really turn some heads at your local field.(This of course is not
true in Germany where high performance silent flight is quite common
I'm sure).
Regards,
Jim
|
| 1426.22 | Calibra report/ultimate f3e kit? | UNYEM::BLUMJ | | Fri Aug 14 1992 15:22 | 30 |
| As my Robbe Calibra nears completion I am starting to get an idea
of what the final weight will be. The wing finished in oracover
with JR 341's will weigh about 22 oz. The fuse with solid fiberglass
covered stab will weigh around 10 oz. So I expect the following:
Airframe - 32 oz.
Keller 70/4 - 17 oz.
14 1000 mah SCR's - 23 oz.
Astro 205 Speed controller - 2.5 oz
250 mah Rx battery - 2.5 oz
7 Channel JR RX - 1.8 oz
From the above it looks like the final weight will approach 80 oz.
which results in a wingloading of 21.5 oz./sq. ft. I'll be curious
to see how it climbs at this weight. The speed should be good
at this weight.
I am currently very interested in Waco's(Weston Aerodesign) 550-10.
The advertised airframe weight is 15 oz. which would result in a
flying weight of 63 oz. using the Calibra equipment. The wingloading
would drop to 16.5 oz./sq. ft. I believe the vertical performance
might approach unlimited. I do not know how the speed would be at
this lighter wingloading. The Weston ship is entirely constructed
of Kevlar with bagged grey foam wings. This might be the closest
kit offering of a competitive f3e ship. I wish I could see one fly.
Regards,
Jim
|
| 1426.23 | Cady Cat Kit | UNYEM::BLUMJ | | Mon Aug 24 1992 17:58 | 33 |
| Hartmut,
Earlier in this note I mentioned a design known as the
Cady Cat. This was based on Detweiler's race rat and is the
premier West Coast 7-cell pylon racer.
It can be built in balsa or composite construction. I checked with
Hobby Horn who offers a partial kit for this design for $60.
You get a fiberglass fuselage with integral fin and faired tailplane
mount and a set of foam cores. You nee only construct the solid
balsa stab and ply motor mount.
I think this kit offers more value than the Graupner Race Rat or
Robbe Micro Racer which both have built up wings and cost $30-$40
dollars more. The Race rat has a heavier plura fuselage and the
Robbe has a built up fuselage. At the speeds these things land,
a composite fuselage is nice for damage control!
If you could get one of the vacuum wizards to "bag" the wings you
would have a tough, world class pylon racer. The construction article
in Model Airplane News(March 1992) states this plane is capable of
90-110 mph across a 150 course.
The span is 32 inches an the weight is 32-34 oz. wing loading is 25.7
to 27.3 oz/sq ft.
I saw one fly at KRC last year. They are real fast!
Regards,
Jim
|
| 1426.24 | One is enough, thank you! | LEDS::KLINGENBERG | | Mon Aug 24 1992 22:55 | 25 |
| Jim,
thanks for the tip. I agree, it sounds like a lot more value for the
money compared with the RACE RAT and the microracer. But I think the
RACE CAT pretty much fills all my need at that end of the spectrum.
I'm really happy with it and for the time being, I am currently more
looking into a floater type glider or electric as the next project.
And I might get into some faster glider (10 cell F3E?) later, but not
this year and probably not next. Since I never really planned to take
part in pylon racing, for just plain fun hotdogging the RACE CAT is
great. I still have the ElectriCub to finish and think about taking
some all-wood kits home. They are by far cheaper than in Germany. I'm
thinking about a HLG and a Spirit or Spirit 100.
If you are interested in the RACE CAT, I have a set of plans with me
that I could send (or copy and send) along with the Elektroflug. Or we
make up a meeting. Turns out we plan on seeing our friends in Guelph,
Ontario during the labor day week. We will probably come through the
Rochester area on Sept. 5. If you could recommend a nice place to stay
overnight, we might be able to schedule a meet. Let me know what you
think.
Best regards,
Hartmut
|
| 1426.25 | Hotel info | UNYEM::BLUMJ | | Tue Aug 25 1992 20:09 | 26 |
| Hartmut,
I have never stayed in a hotel in Rochester, but of course
there are many at all different price ranges. Digital employees
get discounts at several of the better hotels which works out to
about $65 a night, I believe. Below is a list of relatively
inexpensive to mid-price hotels in Rochester:
Brookwood Inn(Digital Discount available, I believe)- around $65
(716)248-9000
Red Roof Inn - (716)359-1100
MicroTel - (716)334-3400
Radisson Inn Rochester(Digital Discount applies) (716)475-1910
I would be glad to let you stay at my house, except we are in the
middle of remodeling and quite torn up.
Let me know if you need any help with accomodations and if you will
be passing through.
Regards,
Jim
|
| 1426.26 | Thanks, Jim! | LEDS::KLINGENBERG | | Tue Aug 25 1992 20:16 | 6 |
| Jim,
thanks for the list! I'll let you know our plans as they develop.
Best regards,
Hartmut
|
| 1426.27 | Electric Breeze reviewed in October 92 M.A.N. | MICROW::PHILLIPS | DECtp Engineering TAY1-2 DTN 227-4314 | Wed Aug 26 1992 17:22 | 17 |
| I just received my October 92 Model Airplane News last night and saw an
interesting field and bench review on the Douglas Aircraft Electric Breeze.
This is an electric version of Douglas Aircraft's Quick Silver aerobatic slope
soarer. Both planes us SD6060 sheeted foam wing and a balsa/ply fuse. The
review built plane used an Astro 05 cobalt with 7 SR 1100mAh cells and a
Graupner MOS 30 speed controller.
The Breeze can be set up as a 3(aileron,elevator,& throttle) or 4(aileron,
elevator,ruddder,&throttle). The suggested kit price is $79.95.
The article clearly states that this is definitely not a novice plane and is
"capable of astonishing speed." The article also recommends not to flair the
landing because "the wing will start flying again and you'll tend to over shoot
the runway." Maybe I can convince "Santa" that I've been a good boy this year
and maybe he could bring me a Breeze. It's never to early ya know!!!
-Lamar
|
| 1426.28 | ast electrics | UNYEM::BLUMJ | | Wed Aug 26 1992 19:55 | 29 |
| Lamar,
I have seen an "Electric Breeze" fly. It is a nice looking
plane, and is highly aerobatic with its SD6060 airfoil. I think
it is a good choice for a high performance electric. The only
two comments I have which are not pointed at the Douglas kit
are:
1) I like plastic or fiberglass fuselages for electrics
because they are much less prone to damage on hard
landings.
2) The wingspan of the breeze is 52" which will give
slower top speed than the typical 31" pylon racer.
This could be a benefit if your reflexes are not up
to a 100 mph airplane.
If you can handle a 100 mph plane, I think the Caddy Cat kit
with fiberglass fuse and foam wings from Hobby Horn is a good
value.
I have an Asto 05 FAI that I hope to put in one of these style
planes inthe near future.
Regards,
Jim
|
| 1426.29 | RACE CAT grounded | LEDS::KLINGENBERG | | Mon Sep 14 1992 23:26 | 22 |
| After a few weeks off, I went to the CMRCM field again yesterday.
I took the whole family with me this time. I brought my RACE CAT with
me, but our son Jan was even better equipped with two planes, a paper
glider and the rubber powered Skeeter.
There was a good crowd out there due to the funfly that had taken place
before, and I had 3 nice flights with the RACE CAT and am finally
really getting used to it and having fun with it.
On the third flight, there were two many noisy planes up there and I
realized pretty late that my battery was going down. I set up for a
landing, but came in hot and high (as usual) and decided to go around.
Unfortunately, there was not enough juice left to gain some height, so
I ended up stalling into a thornbush close to the field. Because of the
momentum of the plane, it ripped the wing off (front dowel and back
holding down torn out) as well as the elevator. Not a big deal, but I
was grounded for the day.
Still had a lot of fun, especially since even the kids enjoyed it.
Best regards,
Hartmut
|
| 1426.30 | | UNYEM::BLUMJ | | Tue Sep 15 1992 19:39 | 14 |
| Hi Hartmut,
Just to let you know my wife and I very much enjoyed our
visit last week. Hopefully your trip to Canada was enjoyable.
I am looking forward to a week's vacation and attending the KRC
electric funfly this weekend.
Just out of curiousity, what was the general reaction to your
Race Cat at the CMRCM field?
Regards,
Jim
|
| 1426.31 | RACE CAT would be neat if it was a little less electric | LEDS::KLINGENBERG | | Tue Sep 15 1992 20:28 | 35 |
| > Just out of curiousity, what was the general reaction to your
> Race Cat at the CMRCM field?
Nice, but too electric :-) :-)
Look into the DECRCM file under weekend wonders. There was some more
distraction around at the field that afternoon :-)
In fact, I think most of the Deccies there on Sunday had seen my RACE CAT
before. There wasn't too much attention, especially as the field was pretty
busy after the funfly. There wasn't much attention to the bad crash of a nice
bipe (Acromaster, I assume) of Mel (a non-Deccie) either, although he crashed
directly into the field that others have a hard time to hit for a landing.
Yeah, we enjoyed your visit, too. Especially that you brought your wife to
entertain mine while we were busy :-). I really enjoyed playing with your
toys. And I agree - to have that white on black in here - that the WACO fuse
is verrryyyy tight. I'd still try and widen the access hole you made on the
top between the wing screws. But it's hard to get all the equipment in there.
I liked the wing and the stab except the Kevlar fraying at the nose, but the
fuse didn't really impress me. The workmanship is far from what I'd expect for
the price you've paid. And I agree, it should have been no big deal to make
a little more room for equipment. I even believe that you could do it with a
little love and passion without adding weight or drag (=surface). I think a
smoother transition from nose (cone) to fuse (cylinder) would reduce more drag
than a little wider a fuse would add. And the bad surface - especially of the
taiboom seam - will need a lot of dead weight to get to look nice. I'd probably
go your route, too: Get it done with 7 cells for now, but plan on getting/
building another fuselage soon.
We had a great time on our trip in Canada and all the way back. It was
just super. Thanks for asking!
Best regards,
Hartmut
|
| 1426.32 | | UNYEM::BLUMJ | | Wed Sep 16 1992 19:57 | 15 |
| Hartmut,
I did not see an entry in the DECRCM conference under "Weekend
Wonders". I can only assume your comment that the Race Cat was
"too electric" implies little or no interest existed.
I've had quite a few flyers inquire about my electrics, which is why
I asked. Knowing the Race Cat is a pretty high performance plane I
was curious if the interest in a fast electric was substantial.
Regards,
Jim
|
| 1426.33 | It was a 'second-timer' for many | LEDS::KLINGENBERG | | Wed Sep 16 1992 22:53 | 17 |
| Jim,
you're right, there wasn't too much interest in the Race Cat on Sunday.
I guess it's partly due to the funfly before and people getting tired
(and then some 'distracted' by Christine). Many reports talked about
the funfly, not that much about people showing up later (see 114.945).
Also, a few Deccies had already seen the Race Cat before. If you're
interested in first-hand attention to be gathered with a Race Cat,
check out notes 115.552-.556 and (no flight, just show and tell) .567.
There is some interest, but I really don't expect many to get into
it. You have to do hi-performance electrics because you like it
yourself. If you are into getting attention, I guess scale planes or
ducted fans will buy you more - for even more money :-).
Best regards,
Hartmut
|
| 1426.34 | Low Interest | LEDS::WATT | | Fri Sep 18 1992 12:28 | 17 |
| Hartmut,
It's true that there's very little interest in electric at CMRCM.
I think that this is due to the cost. Most of the club members have
very low budget planes. (there are exceptions) When you factor in the
cost of a charger and battery packs, electric is a major investment.
Since most members already have the necessary power stuff, they are
slow to invest in the required equipment. Also, some have tried
electrics and failed with them. (electricub, PTelectric) The low
budget electrics with cheap motors and batteries are very poor flying
planes. I've had a couple beginners show up with these planes and they
are not suitable for training!
I was impressed with the Race Cat! In fact, I may build one this
winter since I already have all of the necessary electric equipment.
Charlie
|
| 1426.35 | power/weight ratio < 1 and electric ! | KBOMFG::KNOERLE | | Mon Sep 21 1992 12:23 | 19 |
|
>>> In fact, I think most of the Deccies there on Sunday had seen my RACE CAT
>>> before. There wasn't too much attention, especially as the field was pretty
>>> busy after the funfly. There wasn't much attention to the bad crash of a nice
>>> bipe (Acromaster, I assume) of Mel (a non-Deccie) either, although he crashed
>>> directly into the field that others have a hard time to hit for a landing.
Hartmut,
there is an easy explanation why : they are too used seeing planes
crashing ! I think I've never seen so many planes (Gremlins
especially) crash as the few times I was at the CMRCM field.
And yours even doesn't have an engine upfront.
Charly, imagine the Race Rat with a hot .15 !
Bernd
|
| 1426.36 | Sounds Like Fun | LEDS::WATT | | Mon Sep 21 1992 14:49 | 11 |
| Bernd,
I have a soft spot in my heart for electrics as well for the power
jobs. Actually, I'd like to have one each of every kind of plane. :-)
Everyone's emotions are pretty much drained after a funfly so the crowd
reaction is diminished as well. Gee, I haven't crashed a Gremlin in at
least a week! :-) ?-) I think you caught us on a good HTA day!
Charlie
P. S. I'd like to try a .15 powered Race Cat!
|
| 1426.37 | Pylon Racing in Germany | UNYEM::BLUMJ | | Wed Sep 30 1992 12:42 | 75 |
| Below are excerpts from a British Magazine article entitled "German
Topics" about pylon racing. It is quite informative and short, giving
a good synopsis of what's going on in the world of high performance
electrics.
There are two classes flown in Germany. The FAI class, which means ten
rounds in the shortest time, and the so called "Jedermann-Klasse" that
is flown over 4 minutes. These two classes have become so similar,
that usually only the official FAI one is now flown. Last year, Germany
saw a first German championship with special contests for pylon racing
only. An interesting side effect was that some of the events were
flown together with the IC powered pylon racers, which is usually very
race. There is still a gap between the electric and IC powered, but
with about 100-110 seconds against 80-90 seconds, this is rapidly
reducing. Next year the electric class will probably change to ten
cells(seven now), and together with the Sanyo 1800mah nicads, that will
be available by then, the electric pilots will have a power source of
double capacity for only 15% more model weight.
For some years models have been getting smaller and smaller. Sizes
down to 700mm span were not unusual, until people learned, that size is
not the thing that really makes you happy. It is not the fastest model
that wins, but the one that manages to fly ten rounds in the shortest
time. There is a difference. It may be worth reading the last two
sentences again. The effect i s similar with f3e flying. Competitions
are decided here at the turns(pylons) not between them. A fast turn is
easier with a bigger model that is easier to handle. So German
champion Martin Wombacher's model has a span of 1000mm now, and he is
still one of the fastest. Popular wing sections are: MH32, MH30,
HQ1.5/8, with the MH42 as favorite. Total area should be around 15 sq
dm. FAI max permitted wing loading is 75g/sq dm, but most models are
below 70 to make the start easier. Many pilots have changed to two
ailerons. Some try to use them as flaps, but with little effect.
The motor/prop combination is most important. Motors have gotten
faster, since every brand has in its catalogue a type with 4 windings.
The ferrite motors take a lower current, but weight is lower and
efficiency much greater. There is an unimportant slight difference in
power output. More important is the right prop. Graupner supplies the
6.5x6.5 speed prop, a prop straight of the shelf that is good for 115
seconds on one of the 4 wind motors. For ferrites it should be
shortened a little. The price is low enough for you to optomize the
motor/prop combination without too much cost. Motor running time
should be about 150-180 seconds for the fast ones and 210-240 seconds
for the others.
Training for you on the course is difficult without a half dozen
helpers, but the circuit can be learned without the course. First,
you learn to fly really fast circles around yourself, with a diameter
of about 50 meters. When you have perfected this you may try to do the
same with a diameter of about 30 meters. When this becomes boring it
is time to find a landmark about 180 meters away. Now you can learn
to turn in the distance. Start with big circles, and reduce these
until you think you are losing speed in the turn. The straight runs
should not be a problem. A trick to see if your flying is improving
is to measure your motor run time. The longer it runs, the better is
your flying, provided you do not change other parameters. If you now
feel you really have control of your model, it is time to face the
competition!
**The article showed several pictures, one was of the RACE CAT which is
the longest running design in electric pylon racing and is still a hot
favorite. Martin Schlief is the fastest electric pylon racer at the
moment and is using a flying wing of 880mm span with tiplets and slight
anhedral.
Hartmut or Bernd, if you read this do you concur with the Brit's
assessment of German pylon racing. Also what type of IC motors are
used in German FAI pylon? How big are the IC designs. How long is
a lap?
Regards,
Jim
|
| 1426.38 | I'm not aware of a bug in what you wrote | LEDS::KLINGENBERG | | Wed Sep 30 1992 13:27 | 15 |
| Yep, I read this and from what I can tell (read in mags, never been to
a pylon contest), it's all correct. It's true that the competition
planes are getting bigger (RACE CAT, oldest design, 800 mm wingspan,
RACE RAT, same shape, newer with 1000 mm (=1 m) wingspan). In parallel,
for starters a new class is shaping up: Pocket Racers, they have about
600 mm wingspan and fly on the Speed 400 ($10 motor) with (I guess)
only 6 AA cells. No way you can rave about investment for electrics
there:-)
Sorry, since I don't intend to take part in competition, I don't know
details of the rules and the course. I might be able to dig them up for
electrics, though. Stay tuned.
Best regards,
Hartmut
|
| 1426.39 | don't know nothin' 'bout Pythons aeh Pylons | KBOMFG::KNOERLE | | Wed Sep 30 1992 13:42 | 7 |
|
I only know Pylon races from this screeming lightnings I've seen in the
US, but never saw anything in Germany. The only Electric type of Pylon
racers I've seen is Hartmuts race rat.
I must admit that I'm not too interested in Electric flight though.
Bernd
|
| 1426.40 | SPeed record info. | UNYEM::BLUMJ | | Wed Oct 07 1992 11:16 | 13 |
| Hartmut,
In the now dormant F3E note(386), I noticed you mentioned that
Franz Weissgerber had set a speed record of around 252km/h using his
ARIANE and an ULTRA 2000 motor. Later on you mentioned he had
attained a similar speed with the Hecktoplatt motor. Do you know if
this speed was measured in level flight with the motor running or
in a dive with motor off? I am confused due to the mention of the
two different motors used.
Thanks,
Jim
|
| 1426.41 | Level flight/motor running | LEDS::KLINGENBERG | | Wed Oct 07 1992 12:42 | 16 |
| Jim,
if I recall correctly (didn't look up neither the topic nor the mags),
the speed record was set with the Hectoplett. I've seen a video of the
record flight. The speed was measured with the motor on in level flight
(circles, if I recall correctly). The point he made is that a few days
later he achieved 249 km/h with a regular Ultra2000. So, given the
right model and skills, everyone can do it with motors and radios
readily available. Sure, they are expensive and far from what I would
be willing to spend, but still, it does not need big money and
sponsoring.
Does this answer your question?
Best regards,
Hartmut
|
| 1426.42 | Why not in the F3E note? | LEDS::KLINGENBERG | | Wed Oct 07 1992 12:44 | 7 |
| BTW, why don't you revive the F3E note and put F3E stuff there? It
might help to use the beginners electrics note for beginners electrics
again?
Just a suggestion...
Hartmut
|
| 1426.43 | electric thoughts | UNYEM::BLUMJ | | Wed Oct 07 1992 14:23 | 42 |
| Hartmut,
There simply is not enough interest in electric flight in this notes
conference to warrant separate discussions. It is difficult to
check 3 separate notes(F3E,beginners,fast/pylon) when basically there
are only one or two contributors(you and me!).
The message has come through loud and clear "WE ARE NOT INTERESTED
IN ELECTRIC FLIGHT!!!!!" I have very much enjoyed our correspondence
and learned some interesting things(plus acquired a great motor!), but
I fear we are alone. There are no beginners,F3E,pylon,scale or sport
electric flyers other than you and me! If there are, they certainly
prefer to remain anonymous.
I probably will become a "read only" noter as it seems pointless to
carry on a two man discussion, knowing you and Ed Siegmann are
willing to share information via VAXMAIL.
Information about IC flight abounds in every RC club in the land and
every magazine on the stand. Information about silent flight is
best attained from the other side of the Atlantic and from specialty
West Coast publications.
Enough editorializing! I am amazed that Weissgerber's plane went
that fast under power. I mean that is as fast as the huge RENO
racer models! I thought the 252km/h was the level gliding speed
after a power-off dive. I truly am amazed! That is incredible
performance. I would love to see the video. I am currently
searching for an airframe for the Ultra 2000, which is why this
information is so exciting.
I have heard that you can roughly estimate the airspeed of a clean
aerodynamic design by multiplying the pitch of the propeller by
the rpm in thousands(ie a 12,000 rpm x 8" pitch propeller = 96 mph).
If this assumption is even close to true, the Ultra 2000 must
turn a 10" pitch prop at close to 15000 rpm. WOW! The sound must have
been really neat.
Regards,
Jim
|
| 1426.44 | Don't leave yet | HANNAH::REITH | Jim HANNAH:: Reith DSG1/2E6 235-8039 | Wed Oct 07 1992 14:39 | 10 |
| Sure, get us all interested and then pull up stakes and go read-only!
I just bought a Novak 828 speed control and I'm planning on using it with a
15 year old ferrite Astro 25 in something. I've been keeping a low profile
on this since I wanted to get it working before "going public". I also own
two Astro 05 ferrites from the same era and hope to use them in something in
the future.
If we only rambled about what others were interested in, this would be a
notesfile of "me too".
|
| 1426.45 | makes interesting reading | ITHIL::CHAD | Hi | Wed Oct 07 1992 14:42 | 4 |
| I am a "electric readonly" who likes to read about it, though I don't do it.
If you have something to say, say it, don't stop, please.
Chad
|
| 1426.46 | we're listening | KAY::FISHER | The higher, the fewer | Wed Oct 07 1992 14:57 | 39 |
| > The message has come through loud and clear "WE ARE NOT INTERESTED
> IN ELECTRIC FLIGHT!!!!!" I have very much enjoyed our correspondence
> and learned some interesting things(plus acquired a great motor!), but
> I fear we are alone. There are no beginners,F3E,pylon,scale or sport
> electric flyers other than you and me! If there are, they certainly
> prefer to remain anonymous.
Hey - I resemble that remark!
Seriously - just because most of us are not currently banging away
at the keyboard does not mean we are not interested. I read all your
notes with interest and unlike the usenet have no present need to
comment. That is if you were saying incorrect things or something
controversial that I had a strong opinion on I would comment. Basically
I am currently without a flying electric and I agree with what you guys
have been saying and I am learning about new state of the art stuff
by reading your notes.
Kinda like the 12 year old kid whose first words spoken were to his
mother when he said at supper "this taste awful!".
She said "HE SPOKE, HE SPOKE - why now?"
He said "Up till now I haven't had any complaints!"
Anyway - don't be discouraged by our lack of comment. Nearly all
of us have one closet electric and keep a watchful eye out in this notes
file.
Speaking of my electric Cub - after I broke the Master Air Screw gear
reduction unit I ordered an Astro unit thru Tower. Months later with
still no ETA I canceled the order and took the radio out of the plane
and plan to auction it off this winter. I've been thinking along the lines
of a Mini-Challenger but we'll see. Currently I just have no extra time
to consider yet another kit.
Bye --+--
Kay R. Fisher |
---------------O---------------
################################################################################
|
| 1426.47 | Another, read only noter speaks | SALEM::PISTEY | | Wed Oct 07 1992 15:16 | 11 |
|
Jim,
I generally only read notes. However electric RC is my main
interest. I enjoy very much ALL RC notes , especially any on
electrics. I have experimented with a lotta crazy ideas , made my
own electric ducted fan, worked great, on the bench. Might even be
usefull to push the balsa dust off my bench. So keep discussin
electrics. I need this notesfile badly.
Kevin
|
| 1426.48 | Keep it coming Jim! | WMOIS::WEIER | Wings are just a place to hang Ailerons | Wed Oct 07 1992 15:23 | 4 |
|
I Send Jim a mail message essentially echoing the last few replies. I
guess I made a mistake, and should have posted it instead!
|
| 1426.49 | Jim: Don't Stop Now!!! | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Wed Oct 07 1992 16:28 | 33 |
| This seems almost too late considering all the other noters that
have said basicly the same thing. But...
Jim, please don't become a read-only noter. As one of the
"pioneers" of electric flight in this file, I know what you're going
through. Hang in there and keep the stories and experiments coming.
Even though I have become nearly a read-only noter, it is NOT due to
lack of interest. I have a batch job that sends me the new notes
every day. I read EVERY one (on all topics)!
As many noters have noticed, I have (almost) dropped out of writing
notes. This is due to a few reasons and the primary one is that I
now have a one year old daughter that takes away from the R/C money
and time (building and flying) budget. I feel that I currently have
nothing useful to say so I don't bother to clutter up the file.
I'd *LOVE* to have some of the same plane/motor combinations that
you have. It's through reading about them in notes that I can dream
that one day soon I might be able to afford one and then actually
have enought time to build and fly the darned thing! :-)
Don't stop now!
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 1426.50 | Please keep contributing! | LEDS::KLINGENBERG | | Wed Oct 07 1992 16:28 | 15 |
| Nonono, Jim, please don't go!
Sad enough that Ed Siegmann participates so rarely. I've always
enjoyed his notes and the mail even more so (Ed, are you read-onlying
this?). If you're gone, who shall I talk to? Only these guys that keep
asking why I still don't have a Gremlin:-)
Maybe we can stir some interest one of these days (at least Jim R.s
entry seems to prove we do). And I plan to fly the Race Cat hopefully a
few times before CMRCM is closing (maybe even tonight). Charlie Watt
may build one over the winter. Don't give up on your fellow Deccies!!!
There is hope for them!
Best regards,
Hartmut
|
| 1426.51 | Work..... | OLCROW::PHILLIPS | DECtp Engineering TAY1-2 DTN 227-4314 | Wed Oct 07 1992 19:35 | 23 |
| Jim,
I agree with everybody else, don't give up. I almost gave up the sport because
I've been so busy at work(eating into both family time and RC time.) 90% of my
flying is done during lunch and the only field close enough is a local soccer
field in Acton, MA. That means only quite flight. If it wasn't for quite flight,
I wouldn't be flying!
I've currently got a Uhu with an Astro 05 cobalt that I plan to flying very
soon. I also have a Goldberg Mirrage 550 with floats(use same 05 in the Uhu.)
My first electric was a Davey Systems Fly Baby. I crashed it three times before
I finally gave up on it and went to the Mirrage. I still plan to build that OV10
Bronco, that I spoke of in another note, in the near future. Also after seeing
an electricfied Hurricane on pg 96 of the November RC Report, I gotta build an
electric war bird this winter!! The Acton guys will have to "check there six"
when it gets built. Maybe an FW 190???? :-)
I also enjoyed seeing Hartmut's electric Fiesta fly at the end of Al Ryder's
contest this past Sunday. I hope to see his Race Cat(?) fly before he leaves.
Don't give up on us yet!!!!
-Lamar
|
| 1426.52 | Hey...I do electrics too. | SOLVIT::COLLINS | | Wed Oct 07 1992 20:46 | 18 |
| Jim....
I'm a read only ELECTRIC FLIER who follows all electric notes with
avid interest. I suspose I'm like most read only noters...family and
job have taken up so much of my time lately that I haven't been able to
do much building or flying this season. This winter that will change in
a big way.(my wife wants to know when we can go r/c flying again :-) )
Reading about your interest in F3e and the capability of these planes
plus your reports on your efforts helps keep the spirit in me alive.
Don't go "read only"...there are too many of us like that now. If you
hang inthere, I'll send in an occasional note(when I can contribute
soomething useful)
regards
Bob
|
| 1426.53 | | QUIVER::WALTER | | Wed Oct 07 1992 22:12 | 7 |
| Well, Jim, you must get the message by now. You're like an actor who
can't see his audience. We enjoy what you're doing, even though you may
not know it. I don't know about others, but I find it very difficult
to get the time to respond to notes. Wish I could contribute more.
Dave
|
| 1426.54 | My $.02 | STOHUB::STOSPT::EATON | Dan Eaton St.Louis,MO,USA, 445-6522 | Wed Oct 07 1992 23:14 | 5 |
| Jim, given the prevelant mood at my club (it ain't an airplane unless
its got a big gasoline powered engine up front) I will probably never
experiment with electric flight. I take enough abuse now being the only
helicopter pilot in the club. However, I do enjoy reading your notes
and I'd hate to see them stop. Please keep the information coming.
|
| 1426.55 | APPLAUSE!!! APPLAUSE!!! ENCORE! ENCORE! | VARESE::SIEGMANN | | Thu Oct 08 1992 08:46 | 25 |
| Ciao,
First; thank you Jim for the WACO info. I may end up buying one when
next in US, thereby speeding up my now almost non-existant building.
Since I have gotten busy with one of my other passions, making wood
furniture (having discovered a great source of hardwood right down the
street from my house here) I have become a more than lazy builder of
'electric wings' (this is really what it is all about. Well, that and
spending money...). I also have not had alot of time to enter the notes
business, what with the re-org and figuring out what we should be doing
here in Italy in way of swr devel and then figuring out how to
repatriate ourselves back to US (with a job..). In fact I have not even
flown since August due to holiday and then lousy weather. The sun is
out now so perhaps I'll twiddle the sticks this weekend.
So, with this confession, I hereby absolve myself of past sins of not
keeping up with the electric stuff and thus not being able to thank and
encourage. I will do pennance by reading the notes once per week and
will input when I have something to add. So, Jim, you and Hartmut seem
to have a large enough and appreciative audience to warrent
continuance. I hereby send official electronic applause!! applause!!
which will continue until the encores are performed.
Ciao e grazie, Ed
|
| 1426.56 | Continue, please . | LETO::LEGER | Jean-Claude LEGER | Thu Oct 08 1992 09:00 | 16 |
|
Not yet an acrobatic electric pilot but i' m flying an 2M electric
powered glider (EPS2000 GRAUPNER) for 6 mounth.
It's my first plane . I'm waiting to be a better pilot before
use a faster electric plane. I found all info in electric (beginner)
note very usefull to choose my first plane !
In Europe i was told they want to set all electric plane in an
F5(A,B,C) category .Anything similar in USA ?
Please ,thank for your contribution ,and continue to keep
us inform .
Jean-claude.
|
| 1426.57 | Don't discount the "read onlies" | SNAX::SMITH | I FEEL THE NEED | Thu Oct 08 1992 10:38 | 14 |
| Jim, by all means, keep writing. There's always some little tidbit that
crosses the boundries between glider/power and electric. I don't own
anything electric but that doesn't mean I never will, but I do read
all the notes. As a matter of fact, I "have" been looking at the
EPS2000 that Jean-Claude has been flying which prompts me to ask......
Hey Jean-Claude, how do you like the EPS2000 and how does it fly???????
What are you using for a motor/battery pack combination and what kind
of climb do you get??????? How well does it thermal??????
Thanks alot Jim. Now ya got me going........ 8^)
Steve
|
| 1426.58 | Electrics ? | KBOMFG::KNOERLE | | Thu Oct 08 1992 11:22 | 32 |
|
I don't need no ELECTRICS - let this topic die.
Gas engines forever !!!!!!
@ & % )
^ $ %
# $ % (
+ { } " : ? .,
<> ******
oh ! autch bah hey!
don't ! gulp ! splash!
boing zap
slash slam
\ O / Oh well, we'll have egg and tomato
| salad this evening !
/ \
:-)
I'm very interested in this topic although I don't have any
electrics nor do I plan to. I like the gasers. And I like
to go flying with Hartmut and his 'trics, me with my "Krachmachern"
(noise makers). I think we both enjoy it.
Soooo, the interest is there, it's the money, that isn't !
Bernd
|
| 1426.59 | | UNYEM::BLUMJ | | Thu Oct 08 1992 13:06 | 67 |
| Wow- I never realized so many people were reading these notes! But
then again probably nobody knows I read the power notes, gremlin
notes, decrcm notes etc., since I rarely enter any replies.
Please don't misconstrue my response to Hartmut as a crying complaint
of "Nobody likes what I do". I have become uncomfortable being the
dominant contributor in a dormant note. I feel like a loudmouth at
a cocktail party, boring everyone about some personal interest, which
the rest of the party has no interest. So I thought it best to take
this "limited interest" off line. I certainly will continue to
contribute anything I can.
F3E and F3B are in the dark ages in the USA, even though we are now
a dominant force to be dealt with in the world. Unfortunately, this
knowledge, talent, and most of all interest is confined to a handful
of Californians. There seems to be an assumption that if you live any-
where else in America, you can't do these things. I don't buy the
excuse that the weather makes it that way. I have seen many pictures
of world class flyers in Europe with snow in the background!
What is lacking is interest. It is difficult if not impossible to do
these things without the camerardie(sp?) and organization of a club.
This becomes even more crucial when the members have families and
limited resources to spend on "a hobby". Mark Antry's(remember him)
club appeared to be doing this with F3B. They bought fuselages in bulk
from Hans Mueller, then developed the foam cutting and wing bagging
skills(as a group) to complete their ICON design. The HTA group is
doing it with their GREMLIN-making entry into combat and pylon racing
easy!
There are no competitive, readily available F3E ships for sale in
America at any price. Thankfully, everything else(motors, speed
controllers, etc) are. If the interest existed, I think a fairly
low cost machine could be produced.
In my area, entry into RC is usually facilitated by men over 40 years
old and often over 60. These guys serve as tremendous instructors,
but have a lot of preconceptions and are generally not open to much
"new". I have never met a man over 40 years old in America that was
interested in F3*.*.*! It is immediately assumed that if anyone
mentions the word "team" or "competition" he is a club-splitting
radical! Heaven forbid that the tradition of high wing trainers
and half A**ed pattern ships be questioned. This of course would
undermine the long established "conventional wisdom" - you know
electrics don't fly, gliders are boring, scale is for fanatics,
helicopters are complicated, etc.
I guess where I am going with all this rambling is a desire for
more diversity in East Coast RC. The sport flyer will always be
king and as such, the hardware and information will always be
readily available. It would be nice if there was just a liitle more
room for something different. Eric Henderson's reply "I live in
Massachusetts" to Joe Wurt's question-"Why aren't you flying F3B"
is discouraging testimony to the "limited RC opportunities" in
the East. I hope I will still be flying if and when this ever
changes.
Thanks to all for the encouragement.
Regards,
Jim
|
| 1426.60 | About EPS2000 | LETO::LEGER | Jean-Claude LEGER | Thu Oct 08 1992 13:50 | 39 |
| re .57
> Hey Jean-Claude, how do you like the EPS2000 and how does it fly???????
> What are you using for a motor/battery pack combination and what kind
> of climb do you get??????? How well does it thermal??????
Hi Steve,
I'm very happy with the EPS2000 .It's robust and easy to fly.
Mine is a litle heavy (1.6Kg instead of 1.3Kg witen on the box),
but it doesn't seems to be a problem.(42g/dm2)
I use a Le MANS 360PT (kyosho) with 6 cell sanyo 1300SCR and a 8x4
folding propeler. It give's me more than 3mn power.
It climbs at 2m/s (200m estimated in 1.5mn).
Its first fly ,one evening in may ,after a no so warm day,was 20mn
(with a good glider pilot) and enough power for a second runway
turn, as the first approach was too long ...
We have a 100m short grass runway with wheat arround.
One month ago i do my first full solo flight : 15mn with lot of
swallow around the plane ... swallow gone ... plane landed...
very nice.
I had two crash, one on a too hot start, one on my first try to land,
(i'm not yet 100% error free when plane is coming in front of me).
I'd only the motor couple to be glue again.
My only restriction : be carefull with windy weather ...
you can use the full cell capacity to come back to the runway,
my shortest fly... 3mn and only 50m hight ...
Happy silent flying,
Jean-claude.
|
| 1426.61 | My ESP2000 experience | LEDS::KLINGENBERG | | Thu Oct 08 1992 14:53 | 35 |
| Jean-Claude,
any inputs on the CG? I helped a beginner last winter getting started
with the EPS2000. A son of a colleague got one for Christmas (against
the collected KBO RCers advice). I helped to install everything and get
it airborne.
What bothered me most is that it's really very lightweight as
advertised, but once you put in the gear as recommended, the CG is way
back. So, we ended up putting large chunks of lead in the front and the
battery as far forward as would possibly go (directly under canopy).
It's not the idea of a lightweight plane - especially electric - to put
the weight back in to balance it. Of course, you could probably cut
lightning holes in the tail boom and tail feathers, but then it's not
an ARF any more.
I was impressed with the flying, though. It really flys and glides
nicely. I didn't catch any thermals during the few flights we did (need
to practice to find them in the winter over snow). If I recall
correctly, it tended to tip stall more than I'd like for a beginner's
plane.
Graupner last year introduced the ESP2300 (or some such) which seems to
be the same concept, slightly larger (2.3 m wingspan instead of 2.0)
with a significantly longer nose. My guess is that this would not have
the SP2000s CG problem.
BTW, we flew the SP2000 with the setup recommended by Graupner: Speed600
7.2V, 7*3 folding prop, 6 Sanyo cells and a BEC switch (Robbe
control 7). Unfortunately, the guy involved has too many other
interests and can't stick to the hobby enough to make considerable
progress.
Best regards,
Hartmut
|
| 1426.62 | Race Cat grounded for it's fortnightly (not annual) | LEDS::KLINGENBERG | | Thu Oct 08 1992 15:16 | 31 |
| To get back to the topic (now the ESP2000 really belonged into the
beginner's electric topic), after a flight with the E-Fiesta yesterday
I put the RX in the Race Cat, mainly to finally show Jim Reith how it
flies.
It was another great flight - I'm really feeling more comfortable with
it and can cope with it's speed (it usually passed the pattern ships
and trainers), but landing is still hairy. I broke it again. Since Bob
Palmer doesn't allow excuses any more, I have to admit: I did it wrong.
Too bad, I have a nice list of excuses handy, wish I could use them: I
was distracted by the engine noise of the power planes and not really
sure whether my battery had allowed a go-around. I came in hot and
high. Since I stalled it into the bush with some damage the last time I
flew (no juice for the go-around) and broke it before by landing on
rough ground, I decided to put it down where I was. But the wing was
not really level, it was still too fast and maybe even caught some of
the high grass at the edge of the runway. So it cartwheeled and broke
the fuse again. The fin is cracked, the elevator pushrod bent and the
elevator broke off again. Not sure I'll repair it here. It's easier to
pack this way. Maybe I'll make a new fuse at home and take some time
next year to not only show-fly it, but really practice landing
approaches. The speed and flat glide simply needs some practice, and
it's certainly better to practice in our nice large open fields at
home. Oh well...
Did some more flights with the Fiesta after that. That's relaxing. I
like it more each time I fly it.
Best regards,
Hartmut
|
| 1426.63 | It really moves right along | HANNAH::REITH | Jim HANNAH:: Reith DSG1/2E6 235-8039 | Thu Oct 08 1992 15:33 | 3 |
| I appreciate the Race Cat demo flight. It showed me what an electric can do
and got me going on my Astro 25 project. Now I just have to stop at the hobby
store on my way home and pick up some spare time.
|
| 1426.64 | Pylon in Honeoye in '93? | UNYEM::BLUMJ | | Thu Oct 08 1992 16:15 | 13 |
| I took yesterday afternoon off and went flying, it was such a
nice day, I could not resist. I was talking to another new
member of the club and he thought it would be fun to run impromptu
pylon races next year. To make it fun and easy for anyone who
wishes to participate I will propose an anything goes format, no
rules for engine, wingspan, etc. Most laps in two minutes, one
plane on the course at a time(no midairs). I plan to use a Race
Cat with Astro 05 FAI on 7 cells. I hope there is some interest
cause it sounds like a lot of fun.
Regards,
Jim
|
| 1426.65 | Another ramble... | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Thu Oct 08 1992 20:24 | 51 |
| RE: Note 1426.59
> F3E and F3B are in the dark ages in the USA, even though we are now
> a dominant force to be dealt with in the world. Unfortunately, this
> knowledge, talent, and most of all interest is confined to a handful
> of Californians. [...]
> What is lacking is interest. It is difficult if not impossible to do
> these things without the camerardie(sp?) and organization of a club. [...]
> I guess where I am going with all this rambling is a desire for
> more diversity in East Coast RC. The sport flyer will always be
> king and as such, the hardware and information will always be
> readily available. It would be nice if there was just a liitle more
> room for something different. Eric Henderson's reply "I live in
> Massachusetts" to Joe Wurt's question-"Why aren't you flying F3B"
> is discouraging testimony to the "limited RC opportunities" in
> the East. I hope I will still be flying if and when this ever
> changes.
Very interesting note. Strikes a resonant chord with how I feel.
I've been searching (in vain) for a good slope site for over 3 years
now. Lots of great west facing hills but they're covered with
either trees or houses. :-( Once, I found the perfect open field
on a hill. Two weeks later, it was covered with apple tree
seedlings - an apple orchard. I was bummed.
Similarly, there are no glider clubs in this area. The closest is
CRRC that has a less than optimal glider-only field and another part
time field that they (try to) share with power planes. It would be
great to have something like Terry Tombough has in NM.
I'm also AMAZED at how slow the hobby community has taken to
composite materials (except some glider folks). Seeing the strength
to weight ratio in (for example) the Weston designs makes me wonder
why there is no sport plane with similar design. I guess another
way to say this is that until there is an all foam & glass sport
design that is as popular as the generic Ugly Stik, the average
modeller will look at fiberglass as only good for strengthening the
center section of that new balsa wing or making a cowl.
I could go on, but I've gotta' get home and mow the (overdue) lawn...
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 1426.66 | EPS2000 last. | LETO::LEGER | Jean-Claude LEGER | Fri Oct 09 1992 08:32 | 22 |
|
re .61
Hello Hartmunt,
> any inputs on the CG?
> ...
> ...
I'd same problem with CG . I use 450mA Rx battery ,just behind the
motor ,disable BEC and set the power pack 2/3 under the canopy.
Cuting lightning holes in the tail boom and tail feathers is planed for
winter evenning.Make a new wing (2.2M eppler193) with aileron too ...
I never stall it ,but i don't try to reach its limits !
Moderators ,perhaps you can move .60,.61 and this one to beginner note ?
Regards,
Jean-claude.
|
| 1426.67 | Aerodynamic design | UNYEM::BLUMJ | | Fri Oct 09 1992 12:25 | 46 |
| re: -2
Dan,
I think there are two reasons why composite construction is rare
in IC power designs. First, the people flying the planes are not
familiar with the constructions methods(foam cutting, vacuum bagging,
etc). The second and probably more important reason is the
traditional building methods are well suited to the designs the IC
flyers prefer.
What sense would it make to have an incredibly light and strong
composite Telemaster with a glass-like finished vacuum bagged wing?
The inherent drag of the thick wing, fat fuselage, landing gear,
muffler, propeller, external antenna, gaping space between all
control surfaces, etc. would make one question why the builder bothered
using composites. I doubt one would even notice any difference in how
it flyed.
Composites are better suited to designs which require light weight,
accuracy, strength, and low drag. The technology in IC designs is in
the engines which are capable of amazing power. The IC flyers have
long known this and hence have had no reason to fool around with
"efficient designs". Additional performance can be had by simply
bolting on a larger engine. I recently saw this at my field where a
poor builder's EXTRA 300 came out about 4 lbs. overweight. It flew
poorly on a .91 two stroke, so he simply substituted a 1.08 and it
now flys much better. There was no need to worry about how to get
the design lighter while retaining strength or how to clean up the
plane aerodynamically. The best and easiest solution was to add more
power.
Now obviously if one wishes to build a competitive pattern ship, or
a scale design a little more care in materials selection and building
skill will be necessary. But with the advances in engine technology
(Schnerle porting(sp?), nitro, etc) there is no need for the sport
flyer to worry aerodynamic design. Indeed I have seen power designs
of flying lawnmowers, doghouses, pigs, etc. So why "clean up" a
Telemaster? Balsa, momokote, and a powerful engine will more than
suffice. To any telemaster owner reading, I am using the telemaster
figuratively to represent a typical "sport IC design".
Regards,
Jim
|
| 1426.68 | there are reasons why balsa | KBOMFG::KNOERLE | | Fri Oct 09 1992 12:38 | 19 |
|
There is also the $$$$ - reason. A well constrcted all_wood plane like
Super Sportster, Telemaster, Cap21, Chipmunk ......cost well below the
ones with composite materials. Ask the Pattern guys. They know.
So why to pay $200 and above for a composite trainer when you can get
it for $50 ? And if you ever seen the robustness of a Super Sportster
compared to a all composite plane, you might get annother reason.
And third, I know many who enjoy building in wood. Even if I do
have/had many composite planes (like the big CAP20 that crashed this
year) I prefer building balsa planes.
Just look at Hartmut's Race Rat, isn't that a sleek design - all balsa.
(I must admit in this case that a composite material fuse could be of
certain advantage - right Hartmut ?)
And if you sand fibreglass, you better wear a good mask !
Cheers, Bernd
|
| 1426.69 | Balsa vs. composites | UNYEM::BLUMJ | | Fri Oct 09 1992 15:29 | 32 |
| Bernd,
I am in agreement with what you say. I feel balsa is the
best material for most IC designs. The thick wing chords and
relatively short spans of most IC designs can be built very
satisfactorily with balsa and spruce. Most electric style
power planes use balsa construction because it is the strongest
and lightest material available.
If, however, one desires a high aspect ratio wing of 8% thickness
or less with a span of 2.5 meters or more, which can handle 25G turns,
the limitations of balsa are quickly discovered. It is nearly
impossible to build a wing that meets the above criteria at an
acceptable weight using traditional methods. This is why the
Germans have over 95% of the world full scale sailplane market.
The rest of the world was slow or unwilling to abandon the
traditional methods using wood or aluminum, while the Germans quickly
utilized the new composite structures available.
Like you I prefer to work in balsa and do so wherever possible. I am
not sure if it is cheaper to scratch build with balsa, however.
Foam and fiberglass is pretty cheap and light, quality balsa is getting
more and more difficult to find.
I certainly see no benefit to building Caps, sportsters, telemasters,
etc. using composites other than the resistance of epoxy to the
fuels.
Regards,
Jim
|
| 1426.70 | Yup... | LEDS::KLINGENBERG | | Fri Oct 09 1992 17:36 | 16 |
| > Just look at Hartmut's Race Rat, isn't that a sleek design - all balsa.
> (I must admit in this case that a composite material fuse could be of
> certain advantage - right Hartmut ?)
Absolutely right, Bernd,
in fact, I'm considering right now to put it aside for a while and
think about crash- well, no, but hard-landing-proofing it. Thinking
about a composite fuse or at least more significant strengthening
is one of the lines I'm currently thinking along. I'll keep you all
posted. The flying of this beast has turned into so much fun that
I'm not willing to give up (yet).
Best regards,
Hartmut
|
| 1426.71 | Make a glass fuse! | UNYEM::BLUMJ | | Fri Oct 09 1992 19:10 | 13 |
| Hartmut,
It should be fairly easy to make a race cat fuselage by
sanding a foam plug to shape, covering the plug with fiberglass,
then melting the foam away with mineral spirits. My father made
a fuselage this way, and it worked out pretty well. It helps to
glue two pieces of foam to a stick, so the plug is stiffer and
you can handle it easier and hang it up between coats of epoxy/glass.
Just a thought.
Regards,
Jim
|
| 1426.72 | make a mold.... | KBOMFG::KNOERLE | | Mon Oct 12 1992 06:28 | 9 |
|
I'd consider making a mold. This little fuse shouldn't take much
material, even Polyester resign, what is significantly cheaper than
epoxy, could be used. And you could make many copies...
Would be an interesting project to start with.
Bernd
|
| 1426.73 | Might be the thing to do (you want one, too, huh?) | LEDS::KLINGENBERG | | Wed Oct 14 1992 14:03 | 7 |
| Bernd,
in fact, I was already thinking about this. Especially, since I can use
the current fuselage as a core. I'm afraid it will take me some more
winters to get around and doing it, though...
Hartmut_Epoxy_Slow
|
| 1426.74 | Hmmm, speeding up ..._epoxy_slow | KBOMFG::KNOERLE | | Thu Oct 15 1992 06:34 | 9 |
|
Maybe if we take it as a two person's project it could be done faster.
And if I think about it, the more I like this idea. Imagine - the Race
Rat and a beautiful WEBRA SPEEDY on a tuned pipe.....whow !
How's about the wing ?
Bernd
|
| 1426.75 | Good price on Astro MOtors | UNYEM::BLUMJ | | Fri Oct 16 1992 14:52 | 11 |
| Hartmut,
I picked up a magazine while hanging around the airport last
night and noticed the Hobby Barn had a very good price on Astro
motors. The Astro 60 FAI was available for $180. This seems like a
really good price compared to what Multiplex charges in Germany.
Regards,
Jim
|
| 1426.76 | Not for me... | LEDS::KLINGENBERG | | Fri Oct 16 1992 16:40 | 19 |
| Jim,
thanks for the hint. You're right, I wonder how Multiplex can sell any
Astro motor in Germany. I guess they don't. I already have two Astros
(05 of course, not 60) from here.
I guess I'm not ready to spend that amount of money on a plane. It's
not just the motor, I'd also need the battery (preferably 2, right?)
and the plane. Right now I try to save some money for a new radio. I'm
really not sure I ever would be willing to do the spending on serious
F3E. But maybe something hot in the 10 to 16 cell range some day (not
before 1994, I'm sure).
I've even decided to not get any Astro motor this time.
Thanks again, anyway!
Best regards,
Hartmut
|
| 1426.77 | For Another? | UNYEM::BLUMJ | | Fri Oct 16 1992 18:20 | 18 |
| Re: -1
Hartmut,
I was thinking more in terms if you new someone in Germany
who could use the motor which could be had at a low price. While
probably not in the class of the Hecktoplatt's, it is a powerful
motor which is quite inexpensive. The Hecktoplatt F3E open class
motor is available from Hobby Lobby in the USA for $458. So the
Astro 60 FAI at $180 offers the "Sport F3E flyer" a great savings.
I was happy to get the Keller 70/4 from its country of origin at
such a good price. By the way, if you ever need Astro parts I
would be willing to ship them to you, thus avoiding the high
domestic prices you might pay in Germany.
Regards,
Jim
|
| 1426.78 | Don't know someone personally who might be interested | LEDS::KLINGENBERG | | Fri Oct 16 1992 18:54 | 32 |
| Jim,
> I was thinking more in terms if you new someone in Germany
> who could use the motor which could be had at a low price.
Well, Jim, I don't want to disappoint you, but I already have a request from
a buddy at home to bring him a motor. An even more expensive one. Yes, you
guessed it, a Tartan Twin... We are not all electrics at home, neither...
In fact, I am not in touch with anybody currently who is into FAI F3E. Maybe
it's helpful to not get tempted too much:-)
> Astro 60 FAI at $180 offers the "Sport F3E flyer" a great savings.
Certainly! After all, it's the motor of your world championship team, right?
Do you know whether they modified it or used a stock motor?
> By the way, if you ever need Astro parts I
> would be willing to ship them to you, thus avoiding the high
> domestic prices you might pay in Germany.
Thanks for the offer. I intend to get a couple of brushes now for my 05s and
hope to not need anything else in the foreseeable future. I'll get back to
your offer in case of 'unforeseeable events':-)
How lucky have you been getting piece parts for the Astros? I seem to recall
Ed Siegmann waiting for Astro 60 piece parts for more than 3 months (did you
get them yet, Ed?). I figure brushes for the 05 is not such a big deal -
hopefully.
Best regards,
Hartmut
|
| 1426.79 | ASTRO 60 | VARESE::SIEGMANN | | Mon Oct 19 1992 07:28 | 23 |
| Ciao, (Hartmut and Jim...)
Re my ASTRO 60 fiasco....for the F3E they use a special ('available on
special order..') 6turn rotor and magnet ring. Price $100. This is the
part I actually waited 6 month to have shipped. I also waited 4 months
for a 'regular' 11t 'sport' rotor. I think ASTRO has very limited
production facilities and uses JIT (just in time) scheduling, hence the
long lead times for specials. However they do make good on their
warranty as one of the motors received here (the 6 month 6t) shorted
the rotor after about 1 year. I sent it back, reminding them that
the warranty was way past but asked them to make good as they took 6
months to ship it and had the wrong customs information thus causing
added expense and time. They shipped it, nc and arrived 2 months later.
They are nice people to deal with and you can get Bob B to answer
questions and give advice.
Seem to be good motors and capable of world class performance with
planes designed and flown by experts. The 2 6T here in the club have
been retrofitted with either the 9t or 11t and used in large (15#)
gliders or aerobatic ship.
Ciao, Ed
|
| 1426.80 | Astro question/info | UNYEM::BLUMJ | | Mon Oct 19 1992 12:34 | 44 |
| Re: -1
Ed,
The ads Astro has been running in the magazines list their entire
line of FAI motors(035-60) with a "spec" sheet. The FAI-60 winding
is listed as 6 turns of #20 wire. I am now wondering what the
difference is with the $100 F3E armature.
The Astro 60 motors I have seen at KRC were strong performers. This
year their was a guy who had one in an Aeronaut Sunfly. I am sure it
was a stock motor, and the performance was excellent.
The 60 in Steve Neu's F3E ship may very well be modified, I know he
has a special 5 turn Astro 05 motor in his 7 cell pylon racer.
Bob Boucher(owner of Astro Flight) is a cantankerous fellow, who can
be very helpful or brusque depending on the mood you catch him in.
I think he knows he makes a very good, competitive product. I mean
unless you are willing to really spend some serious money for German
or Swiss motors, who else is their? The USA electric airplane market
is tiny and Bob owns it, so he he is not being pushed to
improve/change any of Astroflight's deficiencies.
Astro probably makes the best motor for the money in America(notice
I said for the money). Below is a cost comparision based on the
latest prices I have seen for unlimited class F3E motors:
Graupner Ultra 2000 - $341
Plettenberg 355/40/6 - $458
Keller "pro" 5 turn approx. $475
Astro 60 FAI - $180
For sport F3E type flyers the AStro delivers amazing performance at
a bargain price. Parts are also readily available here in the USA.
I think the other motors give somewhat higher performance, however,
and parts availabilty may be inconsistent. I have been waiting for
an Aeronaut 5mm prop shaft adapter since May from Hobby Lobby!
Regards,
Jim
|
| 1426.81 | Speed 400 pylon designs | MISFIT::BLUM | | Wed Dec 23 1992 12:58 | 13 |
| The first issue of "Aufwind" I received had many pictures of
commercially available kits and "home brew" creations of electric
pylon models designed to use the Speed 400 motor.
There were built-up flying wings and composite designs. Wingspans
of the "traditional" designs were around 24" using 5 800 mah cells.
Looks like a lot of fun at low cost.
Regards,
Jim
|
| 1426.82 | USA Pylon Update | MISFIT::BLUM | | Thu Mar 11 1993 15:04 | 14 |
| I noticed in an article about the Astroflight Electric Championships
that two of the top US pylon racers(Bridgeman,Manganelli) used the
German "VIPER" design. I am not sure if this is a Detweiller design,
but I think he also used a VIPER at this years electric world
championship. It uses a MH airfoil(Martin Heberle) and is a little
larger than the Race Cat and Cad Cat, I believe(200 sq.in. vs. 180
sq. in.). The German flyers and designers still dominate electric
pylon racing, evidenced by their 1-2-3 finish at the World Champion
ship.
Regards,
Jim
|
| 1426.83 | F3E pylon Hype! | UNYEM::BLUMJ | | Fri Aug 13 1993 14:40 | 107 |
| Finding the Race Cat plan and realizing how much cheaper this is
than F3E gliders, has got me excited about doing a pylon racer.
Liberally borrowing from several Foreign publications, I will
describe F3E pylon racing, using the last world championship
as an example.
Specifications:
1) Electric power shall be provided by 7 NC cells.
2) The motors shall be controlled by radio control to short or cut
the power to the motor.
3) Max weight of 1.25 kg.
4) Scale not necessary, landing gear or wheels not required.
5) FAI number required on model.
The Race Rules:
1) A max of 4 aircraft flown in each heat.
2) All laps flown counter-clockwise round a triangular course.
3) Cut pylons: The lap will not be counted.
4) Hand launch, close to simultaneous as possible.
5) Each race 10 laps of the 400 meter course.
6) A min. of 2 heats must be flown.
7) The CD shall determine the airworthiness of the models.
Scoring:
1) Each second to fly 10 laps gives one point/second.
2) The winner is the contestant who has the lowest number of
accumulated points. With three heats, the highest score
will be discarded.
3) Disqualification of an individual within a heat will give a
500 point score as penalty.
Comments:
As this class started in Europe a certain degree of development has
produced not a single design but a race technique. The European race
pattern is low and tight pulling high G corners around the pylons.
The American and Italian fligth pattern is more oval with large radius
turns around the pylons, this provides a smoother flight pattern.
Last year's World Champiopnship Race:
Individually the German pilots were showing the way. Detweiler,
Kramer, Schlief, and Wombacher in their heats were very impressive.
Dettweiler flying his all black one piece "VIPER" flew a smooth
course leaving the opposition trailing laps behind.
Even after the 10 lap race the little model crossed the line and then
proceeded to climb vertically rolling to a speck, followed by huge
loops before the motor off landing.
Of the Americans, Steve Neu with his Cad Cat and Astro 05 motor stormed
around the course in hell-raising fashion. The EXTASE flying wing by
Martin Schlief semed odd yet spectacular in its ability to round the
pylons and speed down the course. As the afternoon progressed the
adrenaline was pumping high. Dettweiler had the fastest race with
102.9 seconds in round 2, some recompense for his disqualification in
round 1. A quick look at the speed of these models reveals that if
the course was flown perfectly the average speed would be 38.87m/sec
(87mph). The true speed is probably 90-100mph. This form of flying
can be described as exhilirating and stimulates the pilot to fly a
precise and accurate course in an effort to reduce the flight duration.
Final Positions:
1) Wombacher - 211.5 points - "Excalibur 1"
2) Sclief - 216.8 point - "EXTASE" flying wing looks real neat!
3) Dettweiler - 220.4 points - "VIPER"
My personal observations:
I have seen Steve Neu fly the Cad-Cat, Keith Shaw fly his all wood
Hyperon, Chris True fly the Robbe Micro Racer in a mock race at
KRC last year. If you are a hot shot flyer, these ships will
challenge you! With unlimited vertical, incredible roll rates,
and 100+ mph speed they are quit amazing. They sound pretty neat
to! The Cad-Cat or Race-Cat with Astro 05 FAI, 40 amp on/off switch,
and 7 cells can be had for around $200.
Anybody need a copy of the RACE-CAT plan? I've got it.
Regards,
Jim
|
| 1426.84 | Need to get mine going again! | KBOMFG::KLINGENBERG | | Fri Aug 13 1993 14:50 | 10 |
| Your notes remind me that I need to get the RACE CAT in the air again.
I had put it off until I had the new radio (with tray, exponential and
everything) and then all other things got in the way. Now, it's ready
to go, I just need someone to throw it for me for the first flight with
the new radio. It's so fast, it's in the dirt before you have your
hands on the sticks. Once the trims are all set, it's no issue to start
it myself. Maybe this weekend...
Best regards,
Hartmut
|
| 1426.85 | 'Aufwind' Arrives | UNYEM::BLUMJ | | Tue Aug 17 1993 13:36 | 32 |
| I finally got the latest 'AUFWIND' last week and saw the picture of
the C-130 which Joe T. told us about. Impressive! Wish I could read
the text.
I cannot believe the incredible array of electrics and gliders which
I see in this magazine. The workmanship is unbelievable. In a way
it is depressing for us homebuilders, there is no way I will ever be
able to match the craftsmanship I have seen in this magazine. It is
a good thing I do not live in Germany, I either would be broke from
buying stuff or depressed because I could not afford it(the more likely
scenario)!
On another note, which Hartmut discussed some in the past is electric
ducted fans. I noticed in the last edition of 'MAN' that Kress Jets
is moving quickly into this arena. They are offering a ducted fan
unit for use with the Cox .09 engine that produces 18 oz. of thrust.
The unit is available for use with electric motors on 10 cells
producing 16 oz. of thrust. The gas unit weighs 7.1 oz(with motor)
and the electric unit weighs 8.4 oz. witht the Kress jet motor.
The electric unit was advertised at $42.95. They are selling
an electric version of their F-15 Eagle as well as A-10 and a neat
P-38 the prototype I saw fly last year at KRC.
I will be sending for more info. and will post it when it arrives.
I must admit that an electric F-15 is something that I could get
excited about for a winter project!
Regards,
Jim
|
| 1426.86 | My box from Gremany is getting bigger 8^) | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Tue Aug 17 1993 13:51 | 5 |
| Jim,
Joe is forwarding me a set of C-130 plans with my Jet fuselage. I can make
you a copy/let you borrow them for a look when they come in. I was thinking
of using the same technique on a B-17.
|
| 1426.87 | Hobby Horn offerings | UNYEM::BLUMJ | | Tue Aug 17 1993 14:46 | 17 |
| I received the latest Hobby Horn catalog last week and they are
offering some interesting high performance electric gear:
1) USA F3E SE-V/VI short kit for $130
2) Becker 30 Amp on/off switch $34.95(perfect for Race Cat/Cad Cat)
3) Steve Neu F3E 85 amp speed control $120(nice and small, 1.75 oz.)
4) Cad Cat short kit $60
5) Airtronics 9141(metal geared micro servo) $39.95
6) JR micro 341 servo $34.95
*They have the lowest prices on JR equipment I have seen, plus they run
monthly specials.
|
| 1426.88 | More Kress Jet Info | MISFIT::BLUM | | Mon Aug 23 1993 20:37 | 32 |
| I received the flyers from Kress Jets Friday night summarizing
their electric offerings.
They offer a 2.5" diameter Morley fan with their KP1 motor for
$59.95. The unit weighs 8.2 oz and provides 16 oz. of thrust
on 10 cells @20,500 RPM. The motor is warranted for 6 mos. with
a $10 replacement fee(I do not know the details of this warranty).
Also available is the KR-709 3" fan for use with 05-15 size motors
for $69.95 with the KP2 motor(rated at 175 watts). The same warranty
as above applies. The unit weighs 12 oz with an Astro 05 motor
and puts out 16-25 oz of thrust(25 oz thrust attained with 250 watt
motor).
Kress Jets offers an electric version of their F-15 Eagle for $155
list price with 31" span @54-56 oz. weight.
A 50" P-38 that runs on a single 035-15 motor using a toothed pulley
to turn the 9-7 props - $124 list.
A 50" Beech 18 that uses a single motor like the P-38.
A V-1 buzz bomb for use with the small Morley fan.
A 62" twin 05 Pucara available in semi kit for $78 and full kit for
$155, plans alone $18. Complete kite with 2 175 watt KP2 motors
mated to master Airscrew 2.5 to 1 gearboxes for $211.
Regards,
Jim
|
| 1426.89 | Scale electric dreams | MISFIT::BLUM | | Mon Aug 23 1993 20:58 | 38 |
| After reviewing the Kress Jets ducted fan specs, I pulled out
my encyclopedia of Lufftwaffe(sp?) aircraft to start dreaming
about a potential airframe. The Heinkel 162, also known as
"The Salamander" looked like an interesting candidate.
The fan sets on top of the fuselage which allows lots of room
in the fuselage for the batteries to be placed for proper CG.
The high wing lends itself to grass belly landings(no landing
gear-hand launched) without damage.
Interestingly enough the scale Heinkel's engine provided thrust
equal to about 1/3 the weight of the plane. Using the Morley
fan producing 16 oz of thrust would require the designer to
have a plane with a 48 oz. flying weight. The numbers might
be as follows:
Morley fan unit - 8.2 oz. with KP-1 motor
10 800AR Sanyo cells - 12 oz.
RCD 5 channel RX - 1.0 oz
Sanyo 225mah RX battery - 1.5 oz.
Speed control(Jomar SM-4) - 1.0 oz
2 S-33 servos - 1.2 oz
Total equipment weight = approx 25 oz.
If a 20 oz airframe could be built this thing just might fly!
Now what about an A-10 with 2 fans, hmmmm - time to wake up.
Regards,
Jim
|
| 1426.90 | September issue of FMT is out | KBOMFG::KLINGENBERG | | Tue Aug 24 1993 08:04 | 36 |
| Jim,
I just got me the announced FMT September issue. Let me know if you
want a plan of a ducted fan A-10. It's in there, really nice. It's
powered by two Speed 400 6V motors on 10 Sanyo 1000 SCR cells. The cost
of the motors here is pretty close to what you would have to pay for
glow plugs for a glow-engined ducted fan version: They are around DM 10
($ 6). Everything - including the fans - is built up from wood (foam
wing, though) and described in detail; of course, it's not a
beginner's plane.
The data I remember:
Wingspan 1000 mm (39.4")
Weight 1200 g (42.3 oz)
Let me know who wants in issue (I forgot who already ordered one). The
mag including plan costs DM 8 + shipment, but I have to ship a glass
fuse to Jim Reith during September anyway and could include a couple of
mags (unless I find someone to carry it I'll ship it surface mail).
FMT hopes to come out with another plan from the same author: An
equally impressive Mig 15. This flies on only one Speed 400, so your
total engine investment is $ 6. Keep dreaming...
If, on the other hand, this is way to cheap for you: The kit for the
second turbofan (design by Schreckling) is out there. It's only half as
expensive as the French unit: DM 3300 + shipping and tax from Austria
($ 1900). It flies on Diesel + 15% gasoline and puts out a thrust of
300 N (106 oz) and is said to be VERY quiet.
Maybe I should start a business exporting stuff to you guys when KBO
will be closed soon....
Best regards,
Hartmut
|
| 1426.91 | What happens next? | UNYEM::BLUMJ | | Tue Aug 24 1993 12:54 | 10 |
| Hartmut,
I would like a copy of the FMT magazine. I thought about
you when I read the KBO announcement. How will this affect you?
Regards,
Jim
|
| 1426.92 | Will be gone, I assume... | KBOMFG::KLINGENBERG | | Thu Aug 26 1993 16:55 | 20 |
| Jim,
I got a copy for you and will ship it with Jim Reith's Jet kit.
Well, the KBO closing will affect me as much as it can. Since Digital
is closing down the whole operation here in the area (Subsystems will
probably remain someplace in Europe, but nobody knows where as of yet),
I expect to be gone some time between now and the end of the fiscal
year. I assume to be leaving by the end of December. There are some
openings in other storage plants (Shrewsbury MA, Colorado Springs CO
and possibly somewhere on the Pacific Rim (Malaysia?)), but it depends
a lot on the conditions and other opportunities I can find around
Germany. I guess I'll be most probably off this note, the net, and far
away from this area which is probably the nicest flying ground in
Germany. Only good news is that it will take a couple more weeks.
For now, I'm off for two weeks vacation time (finally).
Best regards,
Hartmut
|
| 1426.93 | Aveon brushless motor | UNYEM::BLUMJ | | Wed Sep 08 1993 18:28 | 18 |
| The October issue of Model Airplane News had a small article about
a new brushless motor being offered by Aveon, a California based
company.
Apparently electric plane wizard Keith Shaw has done some work with
the prototype and is very impressed.
He stated that the Aveon motor was more efficient, developing similar
wattage outputs with 10-15% less input wattage. He stated that
his 1983 designed pattern ship(Coulomb) flew better with the Aveon
motor on 8 cells than with the original Keller 25 on 12 cells!
This technology sounds interesting. Hopefully more information will
be forthcoming.
Regards,
Jim
|
| 1426.94 | KRC '93 review | UNYEM::BLUMJ | | Mon Sep 20 1993 20:59 | 80 |
| This year's KRC electric meet in Quakertown Penn. was marred by rain
on Saturday(9/18/93) but Sunday was sunny and a bit windy.
I will provide a very brief overview of new developments and planes
of note.
*Dan Palumbo of Aveox was there demonstrating his brushless motors
with ammeter and tachometer. Keith Shaw actually had one of the
motors running on 8 cells in his "Coulombia" pattern plane. These
motors must be used in conjuction with the Aveox speed controller
which convert the DC Nicad voltage to 3-phase AC. The motor on the
test stand used 42 nicads to spin a 12X7 APC prop at close to 13,000
RPM. The sound was something to hear! Current draw was 33 AMPS.
This technology looks promising. Dan generously donated 3 systems
for the raffle benefitting KRC and the AMA.
*Steve Neu of the USA F3E team(7th at last year's World Championship)
was again present with one of his F3E gliders and a pylon racer.
He is now using a Graupner MC18 system instead of the Vison seen in
past years. Unfortunately his F3E ship was apparently shot down on
its first flight. I was standing next to him when he yelled that
he was getting hit at about 500 ft. The plane went in with the
classic "shotdown profile" - full down elevator and full aileron
deflection. The all molded ship was totalled, but the servos were
functioning when he brought the ship back.
Steve's new Cad Cat pylon racer had a Hektoplatt 320/4 motor spinning
a 6.5x6.5 Graupner prop. The wing sported an interesting new
higher aspect(38") ratio,forward swept wing with an SD7003 airfoil.
The speed and handling of this ship had to be seen to be believed.
With an on/off switch, the entire 2 minute flight is flown at speeds
over 100 mph. The vertical climb is astonishing. A ship this
small, flying this fast, with almost no noise is incredible to witness.
The forward swept wing provides better low speed handling(for
landings) and better stall resistance in the tight pylon turns. The
wing needed a spar and cloth bagged at 45 degrees for torsional
stiffness, due to the loads imposed by the forward sweep. After
Steve's initial flight, all the Cad Cat fuselages offered by a vendor
were immediately sold! Needing only 2 servos(aileron,elvator) a
$35 Becker on/off switch and a $100 AStro 5 turn motor, this ship
provides a lot of performance for relatively low investment.
My fuselage is on it's way!!!!
Several ducted fans were successfully flown and several were not.
The most impressive being Keith Shaw's incredible twin ducted fan
Horten flying wing. This technology is still in its infancy,
requiring the designer to really understand all the variables.
The ones that flew were impressive!
Tom Hunt representing Kress Jets flew 2 twin engined planes
(P-38 and Beech D18) using a single motor mounted in the
fuselage. The P-38 utilized an Astro 035 and the Beech
used a Speed 600. The motors are driven by toothed belts.
The Beech weighed 72 oz., ROG'd and flew in a very scale like
manner. Try flying a single engine plane of this weight on
a Speed 600 motor! The efficiency of twin props was very
evident(2 Graupner 9x7 props).
*Tony Fiore's 1/4 scale Mustang with retracts powered by a direct
drive Astro 90 was very impressive, performing beautiful scale
loops and rolls, with a suprising turn of speed.
*The pattern ships were quite impressive this year with much better
vertical and duration than I have seen in the past. Most were
using 20 or more cells and put in respectable pattern maneuvers.
*The high performance gliders(Surpises, Auras, Sunfly's, etc) were
as spectacular as ever performing beautiful whistling power off
passes, terminating in rolling climbs to 1000 ft. Inside/outside
loops, point rolls, extended inverted flight all were witnessed.
10 minute flights were easily the norm with lots of aerobatics
and 100+ mph passes on the deck. Interest in these machines
seems to be increasing. The cost unfortunately deters many.
***More later.
Regards,
Jim
|
| 1426.95 | ex | UNYEM::BLUMJ | | Thu Sep 23 1993 13:13 | 21 |
| At KRC I met a vendor from Texas, Kirk Massey, who has a company
called New Creations R/C. He specializes in repairing and
modifying Astroflight motors.
He is a talented machinist who among other things lightens Astro
motors by removing excess metal. 1-5 ounces of weight is saved
depending on the motor.
He offers a neat custom motor which is two Astro 25's joined end
to end with a common shaft. It spins a 16-6 prop @6000 RPM on
only 14 cells! Perfect for scaled applications.
He also sells Steve Neu FAI speed controllers for $105. I bought
one at the show. He also offers the Cad-Cat pylon racer fuselage
for $41 and the Snipe F3E fuselage for $81.
Kirk really offers a lot of custom services and parts for any electric
application. He is knowledgeable and talented.
New Creations R/C
(409)856-4630 8 AM - 10 PM CST Mon-Sat
|
| 1426.96 | Hot motor/prop combo | UNYEM::BLUMJ | | Mon Sep 27 1993 13:50 | 19 |
| At KRC, Steve Neu mentioned a hot, relatively inexpensive motor/prop
combination.
- New Astro 25 5 turn motor
-12 x 7 prop
-10 1400 mah cells
The Astro motor is less than 1/2 the price of the European equivalents
(Ultra, Keller, Hektoplatt, etc), is readily available and can be
repaired without any hassles. This combination draws 65 AMPS, giving
1.5 minute runtime. The Astro motor is also very light weight compared
with the competition.
Regards,
Jim
|
| 1426.97 | Ferrite vs. Cobalt | UNYEM::BLUMJ | | Tue Sep 28 1993 15:00 | 21 |
| I am trying to better understand electric motors. A review of the
recent electric games held in Australia revealed that a reworked
ferrite car motor known and marketed as the "Ballistic" was the
hot setup in the 7-cell pylon class. It turned a 7x7 prop at
14,000 rpm. The Hecktoplett 270/4 neodym motor is close to this
performance but draws 15 more amps to do it! The Hecktoplett also
sell for $261(Hobby Lobby) which makes the ferrites even more
interesting.
I was under the assumption that neodym or cobalt magnets had higher
field strength than ferrite, plus were more resistant to
demagnetization due to high temperature. Hence fewer turns of thicker
wire could be used on the cobalts vs. the ferrites.
Why does a ferrite motor spin faster than a cobalt motor?
Thanks,
Jim
|
| 1426.98 | As far as I know... | KBOMFG::KLINGENBERG | | Tue Sep 28 1993 17:13 | 63 |
| 1426.99 | Becoming clearer | UNYEM::BLUMJ | | Tue Sep 28 1993 19:44 | 21 |
| Hi Hartmut,
Thanks for this information, I need to read it carefully
tonight and think about without interruption.
The Hecktoplett 320/4 draws 50 amps static, spinning a Graupner
6.5x6.5 prop. The ferrite motor drew about 35 amps static.
I would assume the voltage the motor "sees" is less with the
Hecktoplett due to the higher current draw.
This is beginning to make more sense to me now. What I remember as
"back EMF" from school days is what you are saying is limiting the
rpm of the cobalt. Is this true?
Thanks,
Jim
|
| 1426.100 | Yup. Back EMF limits rpm. | KBOMFG::KLINGENBERG | | Wed Sep 29 1993 07:26 | 9 |
|
> This is beginning to make more sense to me now. What I remember as
> "back EMF" from school days is what you are saying is limiting the
> rpm of the cobalt. Is this true?
Yes, exactly. The higher the back EMF, the lower the rpm/V value.
Best regards,
Hartmut
|
| 1426.101 | Motor Equations | LEDS::WATT | | Wed Sep 29 1993 10:50 | 8 |
| Normally, a stronger magnet motor will have fewer turns to compensate.
Otherwise it will want to run much slower. Back EMF is proportional to
RPM * Flux * Number of turns. Torque is proportional to flux * number
of turns * current. You still want maximum flux to get the most
efficient motor.
Charlie
|
| 1426.102 | Black Art/Science? | UNYEM::BLUMJ | | Wed Sep 29 1993 14:06 | 62 |
| Quoting from an old textbook - "The torque that a motor produces is a
linear result of the armature current that flows if the field flux
is constant constant. As the motor angular velocity increases, its
back emf also increases. Soon a point is reached where the difference
between the back emf and the line voltage becomes small and the arm-
ature current is reduced. The final balance is reached where the
difference between the two voltages just allows enough current to pass
to meet the torque requirement and the angular velocity(RPM) stabilizes
at a steady state."
What I am trying to make sense of in the airplane world is the
difference between torque and speed. I know a motor that produces
more torque can spin a larger prop which generates more thrust than
a smaller prop. Here is an interesting situation: I want a motor
for a pylon racer, the acknowledged favorite is the Hecktoplett
320/4($261) spinning a 6.5x6.5 prop. However, the Graupner Speed
500BB($86) looks like a very suitable, economically viable alternative.
The no load voltage w/7-cell pack(8.4Volts):
Hecktoplett - 25,074 RPM(Hobby Lobby data)
Graupner - 24,000 RPM(Hobby Lobby data)
Static tests conducted by Silent Flight columnist Frank Moeller:
Hecktoplett @8.4 volt w/ 6x3 prop = 20,000 RPM @ 32 amps
Graupner " "= 19,000 RPM @ 20 amps
*The advertised weight of the Hecktoplett is 9 oz vs. 6 oz for the
Graupner. Also with the lower current draw of the Graupner, you might
be able to get away with 1000 mah cells vs 1400 mah cells for an
additional 2 oz. weight savings. Is it possible that the Hecktoplett
is only 5%(19,000 vs 20,000) stronger at 3 times the price($89 vs $261)
and 33% heavier?
Quoting from the British Electric Flight Association's review of the
recent electric pylon races in Australia - "The hotter ferrite turns
the 7x7 speed prop at an initial 14,000 RPM which is close to the best
we have been able to achieve with a Hecktoplett 320/4 at an extra 15
amps draw. Our suspicion is that the ferrite will unwind more in the
air as it climbs up its efficiency curve and this gives it the
advantage over the cobalts which "hit the wall" at a much lower
efficiency. Dyno tests and flight times suggest a current at speed of
around 30 amps and an efficiency of 70% compared with a probable 40+
amps at 55-60% from a typical cobalt motor."
I am a little confused at this point. The ferrites with smaller
loads(props) seem to good to be true- low price, more efficient,
lower current draw, lighter weight, etc.
All I can figure is that cobalt motors are good for providing a
lot of torque(current) at the expense of efficiency.
Comments/analysis appreciated!
Regards,
Jim
|
| 1426.103 | Depends on your application... | KBOMFG::KLINGENBERG | | Wed Sep 29 1993 15:52 | 46 |
| Re: -.1
> All I can figure is that cobalt motors are good for providing a
> lot of torque(current) at the expense of efficiency.
Jim,
no, I don't think that's correct. As far as I understand it, the
cobalt motors provide alot of torque - the most torque you can get
for the current you want. Therefore, they are the most efficient
way to go for high torque applications (big prop turning at low rpm).
The prop efficiency is also a variable in the equations you have to
solve. And for a slow flying plane (glider), you have better prop
efficiency if you use a big prop turning slowly. If you want to
drive this with a fast turning motor, you'll have to use a gear, and
gears are coming strongly this side of the pond!
Now, for a pylon racer, it's a different story. You need a small prop
with high rpm to get the efficiency you need. Torque is less of an
issue, rpm is the ticket. To get over this back EMF hurdle, you reduce
the number of windings (on your cobalt motor). This reduces the
resistance and increases the current. Also, you get the effect of the
eddy current in the cunductive magnet material from the alternating
magnet field of the turning coil. This eddy current creates a magnet
field that reduces the effective field of the coil (opposite direction)
and therefore, the great efficiency of a cobalt motor at relatively low
rpm goes down the drain at higher rpm applications where the effectivity
of a cheaper ferrite motor might become better.
This is what I understand (as a poor mechanical engineer). Does this
make sense? Corrections (Charlie?)?
I really do believe there is a market and an application for both.
The workmanship on any cobalt motor (and lifetime for this matter) is
still a lot better than that of most can motors.
I talked to Joe T. over the phone last week. He had watched one of the
biggest electric RC meetings here in Germany and was impressed. Most
planes were flown with a gear drive (and I guess many with cheap motors)
this year. Keep following the Aufwind (and the rear cover ad for gears
from Graupner).
Does this help?
Best regards,
Hartmut
|
| 1426.104 | I don't thing the car guys are using them | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Sep 29 1993 16:01 | 4 |
| The other point of reference is the R/C Car market. They're turning
high RPM and using ferrite can motors. This would seen to agree with
Hartmut's statements. Any of the car people want to let us know what
the status of rare earth car motors is?
|
| 1426.105 | Is this the reason why the car guys don't use them? | KBOMFG::KLINGENBERG | | Wed Sep 29 1993 16:15 | 18 |
| Yeah, I thought this before, too (and even mentioned it once). But
having looked a little closer at them (thinking about getting one for
Jan some day), the cars usually have high gear ratios. I guess that
they could simply get rid of the 30.000 rpm motors and use a cobalt
motor with a different gear ratio. maybe they just save their money for
batteries and chargers. Then again, if I lok at the price tag on some
cars, this can't be the only reason.
Cobalts seem to be catching up on boats, though. Anybody out there to
confirm this? I once saw a boat being tested with a Graupner Ultra on
it. It was a wise thing for the driver to first make sure noone was
swimming in the lake at that time. The speed was incredible, but the
boat was nearly uncontrollable. It flipped over when they tried a turn
(did turn, but wrong axis...). However, there is a couple of water
cooled cobalt motors out there (and water cooled controllers as well).
Best regards,
Hartmut
|
| 1426.106 | Maximum Depletion | LEDS::WATT | | Wed Sep 29 1993 17:26 | 10 |
| The trick is matching the motor to the battery voltage and the prop.
More flux will give more efficiency because you will get the same
torque with less current. Winding resistance is a loss term in the
equation which is proportional to current. Trick in a pylon racer is
to deplete the battery as much as possible in a race by tuning the
motor and prop to get maximum performance for the duration of the race.
Charlie
|
| 1426.107 | Get all you can for the time you need. | SNAX::SMITH | I FEEL THE NEED | Wed Sep 29 1993 19:39 | 15 |
| Tuning to race time is exactly what we did back in my car racing
days. We ran 3 minute heats. You experimented with different gear
ratio's until you got about 3 minutes and 10 seconds out of the
battery. But then you were getting beat by someone that was getting
3 min. and 5 seconds out of their battery.
If the system (plane) is direct drive, about all you can do is keep
experimenting with props until you get the performance your looking for.
If you just want to fly fast for a few minutes pick the prop that gives
you that. If you NEED 3 minutes to complete a 3 minute heat, pick the
prop that gives you just over 3 minutes.
If the system is gear driven, which I guess is not likely on a pylon
ship, the more expensive unites have changable pinion gears so you
can still experiment with different gear ratio's.
|
| 1426.108 | DC motor characteristics | UNYEM::BLUMJ | | Thu Sep 30 1993 12:04 | 90 |
| I dug out some old articles from Silent Flight which address DC
motor principles without getting involved in a lot of mathematical
equations.
1. Max. Voltage limit - The voltage generally determines the speed of
the motor and too higha voltage will run the motor at very high
speed. With high voltages the motor currents will also increase
proportionally and the resultant power taken by the motor will
increase by the power of 2. Efficiency generally increased at
higher voltages.
2. Max Current limit - The current determines the torque of the motor
and the heat input into the armature winding and brushes. The
efficiency of any motor is reduced considerably when running at
high currents(cobalt/neodym).
3. Max. power input - Input power is the product of voltage and
current. At very high powers and speeds, the brushes tend to
lift off the commutator. The result is bad arcing which could
rapidly wear the brushes and damage the commutator.
4. Max. speed limit - The max speed of motors are not quoted by
manufacturers, empirical experience is needed.
5. Max. brush temp. - limited by brush material(graphite) which contain
lead and my guess is that they can probably withstand 200 degrees C.
Directly on the commutator surface temperatures could be much higher
than that and heat must be conducted rapidly away.
6. Max armature winding temp. - This will cause the breakdown of the
wire insulation lacquer with a resultant short circuit. Again the
limit is around 200 degrees C.
7. Max. permanent magnet temp limit - Depends on the material used
(Curie temp). Ferrite and Neodym magnets must never get hotter than
100 degrees C. The hotter they get the more magnetism they lose.
Samarium Cobalt can get very much hotter.
8. High power does not necessarily mean high motor weight, but def-
initely means low efficiency, resulting in large battery
requirements or short motor run times(F3E).
9. A low number of winds on the armature means a low back emf
and the motor has to spin faster to create some reasonable
back emf.
Comments from Silent flight review of Graupner Speed 500 BB:
-they have low permanence iron armatures and their iron content is
cut to the bare minimum.
-they have ball bearings and a very low number of winds, so that
efficiencies of over 80% are reached, even at speeds above 20,000
rpm(pylon material!).
-for us these motors are in fact the most interesting development in
the last few years. They appear to have all the advantages:
1. high efficiency
2. high power output
3. high power to weight ratio
4. small dimensions
5. low cost
6. high speed
Hartmut, isn't this the motor you are using in your Race Cat? Is it
really this good?
Regards,
Jim
**Comments on the Graupner Speed 500BB
|
| 1426.109 | It certainly is a good motor! | KBOMFG::KLINGENBERG | | Fri Oct 01 1993 10:05 | 66 |
| Hi Jim,
> 1. Max. Voltage limit - The voltage generally determines the speed of
> the motor and too higha voltage will run the motor at very high
> speed. With high voltages the motor currents will also increase
> proportionally and the resultant power taken by the motor will
> increase by the power of 2. Efficiency generally increased at
> higher voltages.
yup. That's why the F3E guys (battery weight limit 1.1 kg) went with
the smaller 1000 mAh early on. More voltage for the weight than with
the 1200/1400/1800 mAh cells.
> 2. Max Current limit - The current determines the torque of the motor
> and the heat input into the armature winding and brushes. The
> efficiency of any motor is reduced considerably when running at
> high currents(cobalt/neodym).
Also true. You just need some current because you don't want to carry
too many cells.
> 3. Max. power input - Input power is the product of voltage and
> current. At very high powers and speeds, the brushes tend to
> lift off the commutator. The result is bad arcing which could
> rapidly wear the brushes and damage the commutator.
The arcing can damage much more if it interferes with the radio signal.
One reason to not use BEC for high current (20 A is my personal limit
of faith).
> Hartmut, isn't this the motor you are using in your Race Cat? Is it
> really this good?
Yup:-) But, as stated before, it all depends on the application. I tried
the motor in the Elektro- UHU once (original Graupner 7*3 folding prop).
It ran nicely, but not that much better than the plain Speed 600. It's
not worth 5 times the money - for the UHU application.
Now the Race Cat is a different story! It's amazing how this motor can
pull the sleek small plane around. It happens that you'll have to fly
one round until the prop 'catches on' and becomes efficient. It's really
going fast and the efficiency stated in the Graupner catalog (82%) is
not exceeded by any of their cobalt motors (but is exceeded by the
competition variation of this very motor).
Another point you have to care about: As far as I know, the typical pylon
race lasts 4 minutes. The Speed 500 BB Race VS is designed to run on
6 cells (with the Graupner 6*6 folding prop). If you run it on 7 cells,
the current gets higher (Ohms law) and it won't survive 4 minutes. Maybe
it will with the new 1800 mAh cells, but I don't know whether they are
allowed.
As far as I can tell, this is one of the reason why Graupner introduced
the 500 BB Race competition. If you take that one, you have a ferrite
motor with a cobalt price (and efficiency).
The 500 BB Race VS with a Race Cat on 6 cells as I have it is a very
good and efficient combination. Only it's too fast for me:-( I just
crashed it again 2 weeks ago. There is always a couple of months between
flights, and that doesn't help it. I decided to put it at the end of
the building queue and get more training on slower planes first. I guess
I'm just not flying enough to handle a plane like the Race Cat (yet).
Best regards,
Hartmut
|
| 1426.110 | Pylon thoughts | UNYEM::BLUMJ | | Fri Oct 01 1993 12:36 | 71 |
| Hartmut,
From my readings of international publications, I believe
two distinct classes of pylon are flow:
1. "Volks Class" - 4 minutes around a 150 meter course, sometimes
a specific motor like a speed 400 may be required. 7 Cell
maximum.
2. F5D - FAI pylon event 10 laps, 7 cells, any motor.
You are right about the Speed 500 being used in the 4 minute event.
The following quote from the Australian electric games supports
this- "The new Ballistic motor aimed directly at 4 minute pylon
on a 6.5x6.5 prop notched up 41 150 meter legs to blitz the
opposition by an average of 6 legs per round. This motor will turn
the 6.5x6.5 prop at an initial 14,000 rpm and still fly the 4 minutes
, unlike the expensive Graupner Competition and 540 VZ motors which
had previously dominated."
Re: Flying pylon racers
I was talking to Steve Neu(USA F3E member) who is an avid, accomplished
pylon racer. The Cad Cat he was flying was very beat up but was by
far the fastest airplane at KRC this year! Steve's advice, which I
might add he follows, is not to spend too much time building a pylon
racer because everbody eventually cracks them up. His plane certainly
had plenty of battle scars, yet flew beautifully!
The picture I saw of your Race Cat looked like it was impeccably
built(ie too nice to fly!). The Cad Cat fuselage is fiberglass/
kevlar which does not split on hard landings. Foam wings can
also be built much quicker than a rib structure, once the templates
are made.
I agree that flying a pylon ship once every couple of months is
most likely a sure way to bust something. The margin for error
with these ships is slim. It will be interesting to see how I
fare when I get mine built.
Anyway, the Cad Cat fuselage is available for $41 and I will be able to
provide cores. I sent the Race Cat plan to Jim Reith and heard
rumblings about a fiberglass fuselage and foam cores, but I know
he has limited time. So if you ever get back to the States
we'll fix you up with a non-pretty pylon beater plane.
I successful pylon design needs a nearly unbreakable fuselage and
wings that can be mass produced with little time and money. Steve
Neu says he has never spent more than a week building a pylon ship!
Practice is they key, but if you don't have a ship you can't fly.
So build it quick and fly a lot till your skills improve.
I wonder if substituting a tamer motor(ie Speed 400) in the same
airframe might not also be a good idea. I might try this with
the Cad Cat.
Keep flying it! At KRC Keith Shaw and Steve Neu were having
an impromptu pylon Race and one of them commented - "2 minutes
of excitement is much more fun than 15 minutes of boredom".
I know very few pilots(IC or electric) who could successfully fly a
hot 7 cell pylon ship. Don't get discouraged!
Regards,
Jim
|
| 1426.111 | Not for me - at least not now, I'm afraid | KBOMFG::KLINGENBERG | | Fri Oct 01 1993 13:05 | 21 |
| Jim,
I'm not discouraged. In fact, I like the Race Cat more each time I fly
it. But the problem is that I don't get enough training. I get out to
fly every other week or so, and it usually takes me months to rebuild a
simple pylon racer fuse, just because priorities are not on RC, I do RC
for fun:-) No problem to build a Race Cat within a week if you are able
and willing to spend 3 hours/day. I'm happy if I find the time to spend
3 building hours a MONTH. And no, I don't want to change priorities.
At this rate, I don't expect to be proficient enough within the
foreseeable future (especially with KBO closing and us probably moving
next year etc.). Under these circumstances, I might as well give up on
the Race Cat for now and get something hotter again at a later point in
time (maybe something like the Calibra/Cherry/Blue Curry or so).
I'd still like to encourage anyone to try one of these small beasties.
They are definately a challenge and lots of fun (building and flying).
Best regards,
Hartmut
|
| 1426.112 | Fuz/video arrives | UNYEM::BLUMJ | | Wed Oct 13 1993 14:01 | 36 |
| I received the Cad Cat fuselage last night. I was impressed with
the quality. The fuse was $41 and the plans were $6. For $60
foam cores are included(HQ1.0/8.0, I believe).
Hope to fly this ship before next spring!
I also received a video of the 1992 KRC electric flyin. It is
distributed and edited by Astro Flight. Cost is $6.95. It was
quite well done featuring the following planes:
-1/4 Scale Pica Mustang w/ retracts
-1/4 scale Percival Mew Gull
-10 ft. 4 motor flying wing w/ retracts
-Sopwith Swallow
-GeeBee Racer
-Scale Horten flying wing- twin engine ducted fan, 120mph
-Porterfield Collegiate
-Cad Cat pylon Racer
-Stearman Biplane
-Scale Spitfire w/ retracts
-Scale Hurricane w/retacts
-Scale Ligetti Stratos w/ shrouded prop
-Scale B-17 w/ 4 035 Astro motors
All in all a nice lineup of planes including WWI, WWII, Golden Era,
Civilian, Aerobatic, homebuilt, and sport. The video runs about 1/2
hour. I hope to show it at a club meeting soon.
There were 550 planes at last year's meet! It was a great turnout with
beautiful weather which is evident in the video.
Regards,
Jim
|
| 1426.113 | | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Oct 13 1993 14:05 | 3 |
| Jim,
How different is the Cad Cat from Hartmut's Race Cat?
|
| 1426.114 | minor differences | UNYEM::BLUMJ | | Thu Oct 14 1993 11:39 | 22 |
| re: -1
Jim,
The Cad Cat was derived from a 3 view of the Race Cat published in
the German magazine FMT. Steve Neu used an overhead projector to
blow it up. The fuselage is taller and narrower to accomodate the
brushes of the Astro 05 for which it was designed.
The wing and empennage is the same or nearly the same. The Nicad
battery arrangement is different due to the fuselage difference
as follows:
Race Cat - IIIIIII = 7 1400mah cells side by side
Cad Cat - |--||--||--||--||--| = 4 cells end to end
|--||--||--| = 3 cells end to end
Regards,
Jim
|
| 1426.115 | Cad Cat progress | UNYEM::BLUMJ | | Wed Oct 27 1993 12:21 | 15 |
| I received the precision machined Graupner aluminum hub/spinner assembly
from Hobby Lobby yesterday. Using a prefabbed motor mount from Robbe,
I was able to perfectly fair the mount into the spinner(all these
specialty items are expensive but sure speed up construction!).
The wings cores have been cut from pink foam and are ready for
sheeting.
I think this thing will be a handful to fly. It is small and fast
and will probably be hard to see/keep orientation.
Regards,
Jim
|
| 1426.116 | Pick a good paint scheme for orientation | KBOMFG::KLINGENBERG | | Wed Oct 27 1993 14:03 | 13 |
| Jim,
regarding orientation: I did my Race Cat in black and neon pink. Black
fuse with neon decals/pink elevator. Wing bottom black with big neon
circles, wing top neon with black decals.
Orientation was the least problem I had with it....
Curiously waiting for your reports (the Speed 500 BB Race will
hopefully arrive at Jim Reith's this week).
Best regards,
Hartmut
|
| 1426.117 | Hoping for the best | UNYEM::BLUMJ | | Wed Oct 27 1993 17:12 | 23 |
| Re: -1
Hartmut, as you know, landing these planes is very tricky. I am hoping
my experience with the Arcus/Calibra/Surprise will serve me here.
It is probably foolish that my first "power plane"(motor running
all the time) be one of these racers. However, I do not think
there really is a better way to learn to fly one of these things.
The fast higher loaded IC planes at my field use a much different
landing technique than I will need to employ with the Cad Cat.
Hence, I will do the test hop and hope for the best.
Probably building the Electric Breeze from Douglas Aircraft
(50" span, more wing area) would be a better ship to begin with.
However, I am now committed to the Cad Cat, so I will hope for
the best.
Regards,
Jim
|
| 1426.118 | Snow prohibits flying | UNYEM::BLUMJ | | Mon Nov 01 1993 11:51 | 31 |
| I awoke Saturday morning to cold(32 degrees) but calm conditions.
I had repaired damage done to the Surprise fuselage last weekend
and was anxious to fly as the plane had been damaged on the first
flight.
I put my rx battery on charge. I had to do something for work
in the morning and had hoped to fly in the afternoon.
I rushed up to the field after lunch and put my motor pack on
the charger. Hmmm, the wind has definitely picked up and I could
see snow falling on the adjacent hills(my club field is @ 1700 ft.
elevation). It now became a race between the charger and the
advancing snow storm. Just as I got the pack in the plane and
began attaching the wing, the storm hit.
It has been snowing ever since and there is 12" of level snow in
my yard with 2" more predicted for today.
I fear the flying season proper is over!
I am hoping to fly the Cad Cat this winter. It is probably within a
couple weeks of completion, barring interruptions. In some ways
this might be a great winter airplane. With a 31" wingspan, it easily
fits in the car. I can sit in the car while the battery charges,
then step out for 2 minutes of 100 mph flight. I can then go back in
the car to recharge the batteries and my nerves! We'll see.
Not ready for winter,
Jim
|
| 1426.119 | EX - Electric | KBOMFG::KNOERLE | | Tue Nov 02 1993 12:21 | 41 |
|
After Hartmut's last F&C (Flight and Crash) with his electric Race Cat bomber
I thought he was real tired of this plane. Not performance_wise, but
fix_it_wise. After several attempts I finally gave in and aquired the
bones of his "Nicady" (nick name for Nicad lead sled).
The Fuselage got some reinforcement and a
R E A L E N G I N E !!!!!!!!!!!!!!!!!!!
I put in a very ancient OS MAX III 15, the one with cylinder and cooling
ribs as one piece. Old, but it runs very well. I put the fuse on my table
saw (where I usually cut real wood with) and took the head i.e. nose off.
A plywood plate got installed and an engine mount. Then I refitted the nose
so it looks like never taken apart (well, sort of). The radio from my HLG (do
you hear this, Charly ?) was installed in one evening, the conversion from
wing_installed_aileron_servo to fuselage_installed_aileron_servo_with_reduction_
gear annother evening. Total final weight 605 grams (versus 1000 grams as
Nicady).
After several attempts to get the engine running right I tried annother can
of fuel with some nitro - what wonders, the engine ran perfect from then on.
The hand toss is easy now, just let her go ! After some meters pull up till
end of sight - in real HTA fashion. Then a half loop and vertical down. Boy,
this thing is fast ! I would not hesitate to compare it with the Gremrockets
& companies (easy spoken from here, eh ?). Maybe its because its so small,
but it is fast.
To save weight I only put in two servos. So, FTID. (fly till it's dry)
The landings are somewhat exiting, you never know when its hapening untill it
is. Up till now I hit a tree one time and one time I cartwheeled it in badly.
Both times would have been F&C (see above) as Nicady for shure. As Combusty :
one sheered Nylon screw !
I'd say, this Race Cat is one robust construction as Combusty and some REAL
exitment if you like'em fast. Thanks Hartmut for this great little Racer.
Bernd
|
| 1426.120 | How fast is fast? | UNYEM::BLUMJ | | Tue Nov 02 1993 13:45 | 13 |
| Re: -1
Werner Detweiler would not be pleased 8-) !!!!!!!
What prop are you using? Have you tached it?
Without throttle control, how do you know when to setup for
landing?
Regards,
Jim
|
| 1426.121 | | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Tue Nov 02 1993 13:53 | 7 |
| > Without throttle control, how do you know when to setup for
> landing?
When the engine stops, it's time. I used to fly C/L and this was the
way there as well. Generally the engine coughs a bit before hand so
you have some warning when it first starts to suck air. Get up high
enough that you can set up a good approach and go for it.
|
| 1426.122 | I think it's fast.... | KBOMFG::KNOERLE | | Tue Nov 02 1993 13:55 | 26 |
| -< How fast is fast? >-
--------------------------------------------------------------------------------
Re: -1
Werner Detweiler would not be pleased 8-) !!!!!!!
>>> who is Werner Detweiler btw ? :-)
What prop are you using? Have you tached it?
>>> 7x6 reving 13200 rpm on ground. In the air the engine turns much higher
once the nose is horizontal or even downward. The next prop will be a
7x7 reduced to 6x7....The next time I'll fly I'll take a tape recorder
with me and measure the "Doppler-Effekt", the difference in sound as
the plane passes by. I'll get the rev in flight and the speed this way.
Without throttle control, how do you know when to setup for
landing?
>>> never (i.e. when the engine stops)
Bernd
|
| 1426.123 | 05 tests forthcoming | UNYEM::BLUMJ | | Tue Nov 02 1993 13:57 | 13 |
| I heard from Jim Reith yesterday, and am expecting Hartmut's
now orphaned SPEED 500 this week.
I also have a 6 turn Astro 05 FAI motor. I will be performing
empirical testing with these two motors using identical
battery pack, prop, and speed controller. I will post
rpm and current draw with several props. This should give
some real-life data for the ferrite-cobalt questions.
Regards,
Jim
|
| 1426.124 | Must be fast! | UNYEM::BLUMJ | | Tue Nov 02 1993 14:39 | 25 |
| Re: -2
Detweiler designed the Race Cat nearly 10 years ago. He is
currently one of the fastest electric pylon racers in the
world.
For the sake of comparision, the hot 7 cell motors turn the
popular Graupner 6.5x6.5 prop at an initial 14,000 static RPM.
This drops of as the batteries run down.
At last year's electric games Detweiler had the fastest time
of 102.9 seconds(10 laps, 400 meters/lap).
Having seen some of these electric racers flying at KRC at weights
around 35 oz., Bernd's Cad Cat at 600g(21 oz) turning a 7x6 prop
at 14,000 rpm should have incredible climb rate when pulling up
from high speed level flight! Steve Neu's Cad Cat with Hecktoplatt
270/4 is really out of sight in a matter of seconds at 50% more weight.
I would think with the OS .15 you would have unlimited vertical at
speeds aproaching 80 mph. I would love to see this plane fly!
Regards,
Jim
|
| 1426.125 | I'm Motivated! | LEDS::WATT | | Tue Nov 02 1993 18:49 | 9 |
| Bernd,
I may do the same with my Electro-streak which hasn't flown in two
years! It was disappointing in performance with an Astro 05 and the
runs were only 3 minutes at full throttle. (is there any other way to
go but full throttle?) I was thinking of putting a .1 or .15 in it and
wet flying it. Should be a blast! (and the prop will stop properly)
Charlie
|
| 1426.126 | Reverse conversion explosion? | UNYEM::BLUMJ | | Tue Nov 02 1993 19:37 | 36 |
| Charlie,
I am not trying to convert you to electric, as I know
it is not for you. But as a point of interest I would like to
tell you about a couple of modified Electro-Streaks that I
came across.
The first was at KRC where someone had blown the 'streak up
to about 55" inch wingspan. Power was an Astro 40 FAI on
22 cells. This airplane was pretty impressive, good speed
and vertical.
The second was recommended by electric Guru Keith Shaw in a
brand new MAN publication. He recommends using the standard
Elektro Streak with 10 cells instead of 7. This requires
slight modification of the fuselage. He claims the 'streak
on 10 cells will do any maneuver. I must admit when I
went from 7 cells(UHU/Astro 05) to 10 cells(Arcus/Ultra 900)
the difference was impressive.
One other point on reverse conversions(electric to gas) deals
with airframe construction. A properly designed electric
tends to employ lighter and less stock than an equivalent
glow powered airframe. The vibration stress put on the
airframe from an electric is minimal. Some glow engines
I have seen really shake the airframe. In extreme cases
this could be a problem.
Anxious to hear how the 'Streak flys wet!
Regards,
Jim
|
| 1426.127 | I like Both | LEDS::WATT | | Wed Nov 03 1993 10:50 | 15 |
| Jim,
I've had fun with my 'Streak and I'm certainly not turned off on
electric. I have however been looking for a small fast ship to fly
with a minimum of fuss. I agree that the airframe can't take a big wet
engine. I'd probably go with a .1 with 2 oz of fuel. The airframe is
strong enough and the weight would be reduced as well. I was flying on
7 cells and although going to 10 would improve the performance, the
wing loading would be pretty high. I may just build something else and
leave the Streak electric anyway. It was just a thought. I really
like electric gliders but electric sport planes don't cut it for me.
The flights are too short at full throttle and the performance drops
off pretty quickly with the packs I have.
Charlie
|
| 1426.128 | I'd go with the 015 | KBOMFG::KNOERLE | | Wed Nov 03 1993 12:03 | 16 |
|
One important point obviously didn't shine through : By reducing
the weight by 40% the frame will have much more durability than with
the battery weight. And an 015 really doesn't shake that much that
vibration could be an issue.
The Wet Streak would certainly be a nice plane. One point that makes
the Race Cat this fast is the thin airfoil (5%), the wingspan (0.8m)
= 31.5 inch and the sleek fuselage. The last applies for the Streak
as well.
One of my next tries will be a tuned pipe..... am I psyched or what ?
The vertical speed indead is quite high, not shure if its 80 mph YET !
Speedy Bernd
|
| 1426.129 | Lead Sleds examined | UNYEM::BLUMJ | | Wed Nov 03 1993 12:13 | 47 |
| While I agree many electrics certainly qualify as "lead sleds"
I thought I would provide the details of Keith Shaw's Electric
Scale Airforce:
Aircraft Scale Span Area Weight Motor #cells prop wing power
in. lbs. loading loading
**********************************************************************
Spitfire 1/7.2 62" 670 6 Astro 20 12x8 20oz/sqft 70watt/#
40G
deHavill 1/6 88" 900 8.5 2-Astro 28 9x7 22oz/sqft 66watt/#
Comet 25D
Gee Bee 1/6 50" 400 5.5 Astro 14 14x8 32oz/sqft 92watt/#
R-1 25G
Stearman 1/6 64" 1200 9 Astro 60 24 16x8 17oz/sqft 64watt/#
Black Baron Sport
Percival 1/4 75" 800 10.25 Astro 60 28 13x10 30oz/sqft 68watt/#
Mew Gull Sport
Zlin 1/6 65" 650 6.5 Astro 20 12x9 23oz/sqft 77watt/#
526afs 40G
Horten 1/10 62 750 6.0 2-Astro 20 Ducted 18oz/sqft 110wat/#
IX V26 05 modified Fan
King ? 126" 2000 10 4-Leisure 05 10x8 12oz/sqft 55watt/#
Crimson geared ferrite
Aerocom. 1/10 42" 200 2.4 2-Astro 20D 5.5x4.5 20oz/sqft 50watt/#
Shrike
Messer. 1/6 65" 630 6.0 Astro 25G 12x10 22oz/sqft 70watt/#
M35b
What I would be interested in knowing is how these ships compare to
their glo powered equivalent in terms of weight/wingloading. Can
anybody provide any comparisons(real life preferred, not manufacturers
specs as these always seem on the light side in my experience).
Regards,
Jim
|
| 1426.130 | Now, wait a minute... | KBOMFG::KLINGENBERG | | Wed Nov 03 1993 12:39 | 20 |
| Bernd,
you mean the fuselage _WAS_ sleek before it had this ugly cylinder head
sticking out there!
Regards,
Hartmut_had_to_say_something_against_the_direction_this_thread_is_taking...
BTW, I'm still convinced the covering is not delaminating due to the
speed, but due to the glo-glop 8^P
Although I hate to, I have to agree with Charlie that there is a lot of
room for improvement to really get electric racers, acro or scale
planes to work well for an every(Sun-)day flyer. The battery weight is
a permanent threat for big damage if some little thing goes wrong.
Regarding pylon racer, people seem to agree that you have to limit the
time you build into them because you are eventually going to break
them. With the limited amount of time I am willing to spend on the
hobby anyway, this just is not my cup of tea, it seems...
|
| 1426.131 | Why electric? | UNYEM::BLUMJ | | Wed Nov 03 1993 13:09 | 84 |
| The following are interesting excerpts from the recent MAN article by
Dr. Keith Shaw:
Some reasons to consider electric power
***************************************
"An unreliable power system is the most common frustration that defeats
would be modelers. With electric power, there is no cranking a balky
engine, fiddling with needle valves too near a whirlin meat slicer,
unreliable idles or blown glow plugs. Gone are the worries of tank
location, pinholes in fuel lines, structural degradation from oil
soaking, vibration induced radio failures and equipment aging. Instead
you just position your plane on the taxiway, advance the "throttle",
taxi out and take off. the power from an electric is so reproducible
that if you can do a 20-maneuver aerobatic routine when the plane is
new, five years later, you will still be able to do the same routine,
summer or winter, rain or shine.
Aerodynamic and Aesthetic considerations
****************************************
"From an aesthetic(and aerodynamic) standpoint, the awkward
model-engine cylinder, muffler and plumbing spoil the look of a clean
sport model or a painstakingly detailed scale model. With electric
power, a clean, streamlined nose or exact scale cowl is easily done."
Versatility
***********
"Many projects that are usually considered tough or impossible become
easy, or at least feasible. Twins and multi-motored aircraft are
almost trivial, as problems of synchronization, single engine failures,
cramped nacelles, and structural nightmares are nonexistent. Pusher
configurations invariably suffer the problems of overheating, fuel
flow, muffler interference and balance. When using electric power,
only a small motor would be mounted in the tail, while the battery
pack is positioned in the nose, eliminating the need to add lead to
get the correct balance. There would be no need for pusher props
as most electric motors can be made to run in either direction. The
easy addition to gearboxes enables an electric motor to turn very
large, efficient props with modest horsepower. Many scale models
of radial-engine aircraft do not need extreme levels of horsepower,
just a sensible amount efficiently coupled into a propeller large
enough to clear the cowl. With glow power, a grossly oversize engine
engine is needed just to get a little bit of the prop beyond the edge
of the cowl."
Power Control
*************
"One of the real advantages of electrics is the efficient, accurate
control of power. Since good motors can stand very high powers for
short times, the plane can be propped for the highest power demand,
such as vertical roll or vertical 8, and flown at reduced power for
the remainder of the flight.
Keys to success
***************
"Invest in good equipment. Trying to get away with cheap car motors,
old questionable ni-cads or an oil soaked glow airframe are ways of
guaranteeing failure. Finally- practice,practice,practice! While
virtually everyone will imagine I'm talking about 8 point rolls or
Lomcevaks, it is important to learn to land correctly every flight.
Careful landings dramtaically reduce the structural loads and weight
requirements of the airframe. 50% of the weight in a typical glow
powered kit is just there to allow it to survive the occasional
"hard landing". You've seen them: the pilot lands about 3 feet high,
the plane stalls, drops a wing tip, cartwheels two or three times,
flips end over end on its back. And the pilot is really mad that he
broke another @#%!prop! Once the hard landing barrier has been
overcome, the structural weight can be reduced to a point where the
total flying weight may actually be lighter than a glow plane of
similar performance, while maintianing every bit of aerodynamic
strength. Learning to fly efficiently will also improve the
performance and extend your flight time. Thee single most power-
consuming maneuver is gaining altitude. Random climbing and diving
or "horsing" the plane around the sky will lead to shorter flights.
Climb to a comfortable altitude and base your aerobatics and circuits
relative to this reference line. Smooth flying, rudder finesse and
power management can easily double your flight times."
Comments?
Regards,
Jim
|
| 1426.132 | not worth reading... | KBOMFG::KNOERLE | | Wed Nov 03 1993 13:31 | 12 |
|
I'm not shure that this writing is really worth any reply. This might be used
for beginners with no (0) experience to try to convince them using Electric
power instead of combustion engines. Any modeler with some experience will
be able to find garbage and phrases in each chapter.
I'll quote it as a cheap shot from one obviously arrogant person who cannot
accept other than his own philosophies.
Bernd
|
| 1426.133 | Garbage-really? | UNYEM::BLUMJ | | Wed Nov 03 1993 14:45 | 41 |
| RE: -1
Bernd,
I'll assume the "obviously arrogant person" you refer to in
the previous note is Keith Shaw and not myself. At the end of the
article which I drew the quotes from in .131 there is an "about
the author" caption as follows:
"Keith Shaw is one of the foremost electric-flight modelers of our
time, and his beautiful, scale electric models have frequently
appeared in the modeling press. Keith has been fascinated with
flying machines his entire life. After starting with free flight
and control line models in the early 50's, Keith entered the world of
R/C modeling around 1960 using home made vacuum-tube radio equipment.
In 1975, while competing in pattern, scale and pylon, Keith became
interested in electric flight. This interest has since grown to
dominate his time. He flies in several dozen airshows each summer
to demonstrate the advantages of electric flight.
Keith is a senior research scientist at the University of Michigan,
where he develops exotic instumentation to study molecular structure.
In his remaining "copious spare time", he enjoys rock 'n' roll and
an occasional few hours of sleep."
Keith is a very friendly, helpful man who as usual includes his
home address at the end of his articles to assist people with
questions. I have never found him to be arrogant.
With 4 decades of modeling experience(wet/dry), prestigous award winning
designs featured in national shows and publications, I think it
was a glib remark to refer to his views as "garbage". I invite
intelligent disagreement/agreement to any of the points presented,
but do not appreciate "mudslinging" at large.
Regards,
Jim
|
| 1426.134 | Bernd's on the Mark | LEDS::WATT | | Wed Nov 03 1993 15:55 | 17 |
| I agree with Bernd (about Keith Shaw)!!!! This is obviously slanted
toward electric. A beginner is just as likely to have problems with
electric reliability as with glow. Matter of fact, if you aren't a
battery expert, electric can be frustrating and expensive. I'd like to
see cost estimates on the power systems in his "Scale Airforce". I
know that my electric equipment was more expensive than equivalent
glow. I have tried to teach on electrics and it doesn't work very well
because of the short flight duration. As was stated earlier, the
battery makes a great battering ram in a bad landing. (crash) My
Electrostreak has only survived because I can grease it in. It flies
well and lands fairly hot. I would submit that any structure that can
hold the battery could stand up to properly sized glow power. I would
worry more about flutter at high speeds than about the wing folding or
the fuse breaking.
Charlie
|
| 1426.135 | | QUIVER::WALTER | | Wed Nov 03 1993 16:10 | 11 |
| No one has mentioned yet one of the safety drawbacks of electric:
instant on. One thing about a glow engine, if you don't spin the prop,
it won't start. Electrics can come on, at full power, at the most
inopportune time. You can't just blithely turn the radio system on, you
have to THINK first.
Not that I'm against electrics, I'm not. I just thought it should be
considered to balance out Shaw's list.
Dave
|
| 1426.136 | Plus and Minuses :-) | LEDS::WATT | | Wed Nov 03 1993 17:10 | 13 |
| Another safety issue - if you jam your hand into an electric, the
torque just increases - you get more torque as prop speed drops. IC
engines will stall if you load them excessively. Electrics must be
treated with respect always since the motor can start without warning.
Battery charging can be dangerous if not done properly. Nicads should
not explode any more if the vents work but they can get mighty hot if
you over charge them.
Not pointing out the drawbacks really detracts from a discussion of the
advantages of electrics. There are tradeoffs with everything. Each of
us places more or less emphasis on different features which is why
some will only fly electrics and some won't fly them at all.
Charlie
|
| 1426.138 | | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Nov 03 1993 18:08 | 3 |
| Maybe you don't have to go so far east. I'll save you an hour on
the trip and go out flying with you with my 16 cell Jet in the
spring.
|
| 1426.139 | Sorry!!!!! | LEDS::WATT | | Wed Nov 03 1993 18:14 | 11 |
| Jim,
I hope we didn't come across as hostile. :-) I liked Hartmut's
Race Cat. I'll probably even build one if I can fit my Astro 05 in
there with the brushes sticking out. I really like my Eclipse electric
glider. Our field is not kind to high starts and winch lines but I can
launch my Eclipse and get a couple solid climb outs with it on a
charge. One thing you can do with this that you can't easily do with a
gas job is restart the motor. :-)
Charlie
|
| 1426.140 | | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Nov 03 1993 18:25 | 3 |
| It also allows for flying before the 10am as well.
Local field exclusion for noise
|
| 1426.141 | A moderators nightmare.... | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Wed Nov 03 1993 18:26 | 16 |
| < Jim,
< I hope we didn't come across as hostile. :-)
Please understand that Charlie does not speak for all of us. Ol' EVL-1
'ere thinks that electrics suck!. The opinion will stay that way until
they can haul a 5 kilo plane straight up and out of sight for a whole
FAI routine!.
While I am about it - the only real gliders are F3B and Helicopters are
for the ducks????.
How's your day so far???. :-)
Regards,
EVL Eric.
|
| 1426.142 | Right On Track | LEDS::WATT | | Wed Nov 03 1993 18:51 | 10 |
| What would you expect from the Evil one other than Hostility?? :-)
He doesn't even like most gas jobs. If they don't have seven servos or
a YS120 they just don't cut it. He makes exceptions for Gremlins but
only because he's their creator.
And he's having a bad day!
Charlie
|
| 1426.143 | No cure......... | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Wed Nov 03 1993 19:03 | 10 |
| Not too bad a day. My team just got a mini mention on the US DVN.
And with the Gremlins, I do prefer them to be overpowered! :-)
You know what they say. "Once an IC always and IC"
or "2-c or not 2-c. Watt is the question"...
Exit E.
|
| 1426.145 | Whooooooaaaaaa!!! | QUIVER::WALTER | | Wed Nov 03 1993 20:53 | 32 |
| [Offhand remark: Y'know, these notesfiles are sometimes like an
extended family, complete with friendly banter, heated arguments,
antagonistic retorts, pouting... you name it, it's all there.
You'd think we were living together!!!]
I guess it's my turn to smooth some feathers. Jim, I don't contribute
much to this note because I'm not currently flying electric, but I
always read it, and I look forward to your notes because they generally
are full of information I don't see elsewhere. You are an electric
fanatic, and that's great! I like the enthusiasm.
From what I could tell, Keith Shaw's statement was meant to drum up
some more interest in electrics. That's fine, but there's two sides to
every story, and he just told one side. I think most of our comments
speak to that (at least mine do). I applaud Shaw for his
accomplishments, but I also agree that electrics are not for everyone.
As usual, some opinions in this conference are entered a bit more
forcefully than others, and maybe a bit out of context, but you just
gotta let that stuff go like water off a duck's back! Ignore it, and
concentrate on people who are serious with this topic. The others will
get bored and go away. And that's fine too.
By the way, I still have my Astro 05 cobalt system which I pulled out
of my Challenger, and I intend to stick it into something this
winter... something faster and cleaner than a Challenger. I plan to
review this topic for some suggestions that were made a while back.
Stick to it, Jim.
Dave
|
| 1426.146 | Keep it up | SHIPS::HORNBY_T | Soarers are rarely Silent | Thu Nov 04 1993 09:26 | 17 |
| Here Here Dave..
Jim,
You're efforts are highly valued in both electrics and F3B in my
camp.
Please keep it up.
I believe there are many more quiet readers than the minority critics
(critics who in most cases are just providing amusing banter which
helps with our well rounded notes file.. don't take then too seriously)
Perhaps the silent majority could voice a short opinion...
Regards Trevor
|
| 1426.147 | I'll drink to that! | BAHTAT::EATON_N | Smile when you say that! | Thu Nov 04 1993 10:40 | 12 |
|
Jim,
I agree absolutely with Trevor's comments. I'm at the stage of kind of
"circling round" electrics, sort of keeping an eye out, and I'll really
do it one day! 8^)
I do value your items, and they are gradually nudging me closer!
Cheers
Nigel
|
| 1426.148 | SORRY - Don't Stop | LEDS::WATT | | Thu Nov 04 1993 10:54 | 15 |
| Jim,
Some of us tend to jab at the notes just to get more people into
the conversation. The file has been pretty quiet lately! I too read
your electric entries with interest and I also agree that there are
probably more silent readers than active ones. Don't Stop!
Charlie
Still waiting for that battery breakthrough :-)
By the way, 20 years ago I was working on electric cars (full size not
models) and I was really into batteries and motors. I think we'll see
some serious electric cars on the road in a couple of years.
|
| 1426.150 | May the RC Gods be kind to you | SNAX::SMITH | I FEEL THE NEED | Thu Nov 04 1993 12:07 | 47 |
| I've been sitting here for a few minutes now waivering back and forth
between putting in a response and just letting it go. Obviously I've
chosen to respond.
Jim, it seems as though your insisting on leaving on a bad note. I'd
like to not see that happen. By the same token, the comments seem to
have swung from electric banter to questioning the integrity and
personal "make up" of other noters. So if you insist on quiting the
notesfile, I'd just like to set the record straight.
There is, in fact, a very large and very serious glider contingent
here in mass. I'm one of them even though I'm also a "pattern" flyer.
I take BOTH seriously. I don't do EITHER as much as I'd like, but I
still enjoy both very much. I'd hate to be considered rude JUST because
I fly pattern.
As far as feeling unwelcome, well, people can "make" themselves feel
however they want. We have, in fact, hosted several visitors from
around the country and I challange any of them to say they weren't
welcomed REGARDLESS of what they flew. Hartmut has made several trips.
He competed in one of our largest glider comps while he was here. He
brought his ELECTRICS down to the CMRCM field and everyone was very
interested in seeing them fly. Back when we were having the DECRCM
meetings, Hartmut put on a VERY indepth demo on props, mufflers, and
electric stuff. Complete with slides and everything.
Mark Antry, before he left DEC, used to come and visit. People would
get together SPECIFICALLY to go glider flying with Mark. Bernd is
into electrics as well as power. We always look forward to his visits.
I even let him CRASH my Unic the last time he was here. 8^)
One of the down sides to using computers to communicate is that it's
EXTREAMLY 1 dimensional. It's SO easy to take something the wrong way.
That's why everyone uses smiley faces to insure people understand that
there only joking. Admittedly we do alot of poking fun at each other
and probably forget that people that don't know us might get the
wrong idea. I appologize for that if that's what happened. However I
do think there is anything more than mis-communication here.
If you insist on leaving, that's your God given right, and although
your input will be missed we cannot do any more than has already been
done to try to stop you.
The only thing I ask is that, for the sake of others that may visit
in the future, you don't falsely label us when, despite invitations,
we have not had the opportunity to show you what were like in
real life.
|
| 1426.151 | don't go now - it's just getting interesting | KAY::FISHER | A watched pack never peaks. | Thu Nov 04 1993 12:28 | 39 |
| > <<< Note 1426.149 by UNYEM::BLUMJ >>>
> -< It was fun for a while...... >-
> Most important to me in life is to have friends. I do not feel if
> I was to come to the HTA field I would be welcome because my plane
> has an electric motor(or worse yet if I brought a glider!).
I can't tell you how many fist fights I had with my best friend when
I grew up in Minnesota - we're still good friends although I haven't
seen him in many years.
I think you would be pleasantly surprised if you brought any plane
to an HTA field. Actually there is no HTA field all HTA's are DEC
employees that are members of other clubs. Certainly most are members
of the CMRCM club but many CMRCM members are not DEC employees and are
not considered HTA's. For what it's worth every year CMRCM puts on a
terrific glider contest. In fact I attended my first glider contest
at the CMRCM field and took last place in all three classes. I had a
ball and learned a log and made quite a few friends.
Don't give up on us Jim. I read all your notes and most importantly
I consider you a friend. I only have one electric plane currently
but I must admit these fast electrics sound interesting.
Take a nice hot jacuzzy tonight and poor a little skin thickener in.
Don't let the fast electric note die like the trivia note did when
Al Casey left.
Dave Walter's reply was pretty accurate - your a member of the family.
In fact your starting to act like my big brother - just kidding.
Bye --+--
Kay R. Fisher |
---------------O---------------
################################################################################
|
| 1426.152 | Ramblin' | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Thu Nov 04 1993 13:17 | 51 |
| Jim,
How you deal with it is your own perrogative and I have your email
address for my future electric questions. It's probably time to
back off from the file for a bit and take a deep breath and put
those energies into cranking out an "I'll show them" electric.
This notesfile really is an extended family and when I've had gaps
between contracts, I've felt lonely and suffered withdrawl. It's a
lot quieter in here with all the people that have been TFSO'd and
the threat of "why are you in notes" hanging over people's heads
(answer: Because I have a big compile running for 20 minutes) and
sometimes unique ideas aren't well recieved. I've got a couple of
projects going that I haven't discussed in here specifically because
I don't want them "designed by committee" and I want to succeed or
fail on my own. There are other projects that I make quiet reference
to (like my electrics) just to let the observant know that they are
not alone (hint hint, Jim 8^).
If we don't exchange information on non-mainstream topics (if you're
saying this has become a Gremlin/Pattern file) then we won't expand
our horizons and learn from other sectors. Electrics have some major
hurdles to solve that other planes will benefit from. They need to
be both light and strong. The battery battering ram needs to be
controlled. This is a technique that is going to prove useful in
ALL aspects of the hobby. Last night I spent an hour on the phone
with a Formula 1 pylon pilot. I don't fly pylon so I couldn't relate
but due to my glider background, I could give him techniques for
reinforcing a sub-inch thick wing under significant load. We both
learned something from the conversation which we'll apply to our
interests even though the R&D was done in the other guy's field of
expertise. I don't go to pylon contests but I could learn another
set of techniques if I did. This notesfile is like that. It reaches
around the world and brings far more to my attention than the
limited time I get reading magazines. Most times a reference in
here will point me to an article in a magazine I have sitting at
home. I don't want to see that diminished (rather selfish of me 8^)
And if all you want to read is one specific topic, "next unseen"
works well. Remember that the info that Jim entered was from Keith
Shaw (who doesn't read this file) so there's no reason to comment
back directly. You can refute the remarks and that's positive
discussion but backing it up with more info is constructive rather
than just passing judgement on it being crap.
There's a lot of info out there that isn't in this notesfile and it's
difficult to discuss it unless someone takes the time to enter it in
which isn't as easy as entering a 10 word dismissal.
Thanks. I feel better now that I've entered that and you can always
"next unseen" it if you don't want to bother with it.
|
| 1426.153 | Every cloud has a silver lining | SNAX::SMITH | I FEEL THE NEED | Thu Nov 04 1993 14:27 | 9 |
| We can now have new tee shirts made up.
A A A
Abrasive Aerobatic A__holes
Sounds like new shirts and hats to me. 8^) 8^) 8^)
A sense of humor does wonders.
|
| 1426.154 | 8^) | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Thu Nov 04 1993 14:32 | 3 |
| >Every cloud has a silver lining
Has to be gold stickered for 1991
|
| 1426.155 | It get's worse | SNAX::SMITH | I FEEL THE NEED | Thu Nov 04 1993 14:37 | 2 |
| Ya, I was going to throw a party a couple of years ago with live
music, but had to settle for a DJ. I couldn't find a NORROW BAND.
|
| 1426.156 | We're OK - Really | LEDS::WATT | | Thu Nov 04 1993 14:38 | 14 |
| Jim,
I think you have made your own decision without having any facts.
I have never seen any of the local Decies bad mouth anyone for their
different interests and all visitors have been welcomed to our clubs
to fly and BS with us. I may want to fly plane type X but I don't care
at all what someone else wants to fly as long as it's done safely. Our
field is not well suited to gliders but we do fly them there. (Yes, I
have a gilder too.)
I hope you don't leave these discussions for the reasons you stated
because it just isn't true.
Charlie
|
| 1426.158 | there is a lot of us silent people | SALEM::PISTEY | | Thu Nov 04 1993 15:21 | 19 |
|
I am mostly a silent noter. I do however read every note entered
whether electric or whatever. (even h-woppers, although if I find
what key is the "next unseen" maybe not 8-)>..) RC is my obsession
and electric experimentation consumes most of my time. Gliders
next. I am sure if it was known how much I have benefitted from
the electric info , as well as glider, I would probably be billed
for it. 8-0>.
Perhaps I am part of the problem perceived, in that I do not
participate much. But beleive me I really look forward to any
info presented here, and I for one have a lot of respect for
Keith Shaw. Just one of my many heros. I believe most others in
here also respect the man.
Hope all this good stuff continues.
kevin p in newhampsire
|
| 1426.159 | | STOHUB::JETRGR::EATON | Dan Eaton St.Louis,MO,USA, 445-6522 | Thu Nov 04 1993 16:08 | 54 |
| RE: 1426.15
Jim,
Do what you need to do but don't give up on getting electric info into the
file. I enjoy your input. I'm just not doing anything electric worth commenting
on. It's sort of like the helicopters. if somebody new comes along and has
questions I'm glad to give them a hand but not that much is happening with
me that would be of interest to other enthusist. You on the other hand seem
to get a great deal of info on the subject of electrics and I appreciate your
efforts to let us know.
Regarding Eric not liking Electrics, Helicopters, Gliders, and a host of others,
That's just Eric. I always figured he just wasn't skillful enought to handle
them. We tend to not like what we can't do well. 8^)
Regarding
> Off the subject - Why was the DECRCM notesfile created? I never
> knew what its origins/charter was. I had assumed that you needed
> to be a member of some Massachusetts DEC R/C club to participate.
> Why would information be entered in one conference(this one) versus
> the other(DECRCM). I have never fully understood this.
You do know how to pick topics to stir up interest don't you?
My view is...
Once upon a time there was a notesfile. It was called RC notes and a lot of
people stuck with it thru two or three deletions/accidents. As time went on
it became hard to find previously discussed items of interest. About this time
somebody came up with the idea of forming the Digital Equipment Corp. Radio
Controlled Modlers (aka DECRCM). Part of the reason for forming the group was
for commaradry amoung folks local to the greater Boston area and the other
part was to cover our collective butts as at the time we were sending video
tapes and magazines using distribution list thru the interoffice mail. DECRCM
was dominated by but not exclusive to the folks in the GBA. I was even a
member of it.
Somebody came up with an idea. It wasn't a bad idea but it ended up being
implemented poorly. The idea was to make the information in the RC notesfile
more easily accessable by cleaning up the file. From that point things went
down hill with much of the arguments just voiced regarding Eric's latest
proposal being voiced for the first time. The end result was the leadership of
DECRCM at the time decided to create the DECRCM notesfile. I was told the idea
behind it at the time was to see which was the better product and obviously the
better notesfile would be the one that everyone would use and the other would
die on the vine.
It didn't quite happen that way. People started using the DECRCM file to discuss
the day to day BS that goes on and using the RC file for stuff of long term
interest. Given good moderation, I agree with Eric that we could probably get
by with one notesfile now days. Use several notes for the day to day stuff and
delete the crap after a suitable time period, leave the other stuff alone. But
getting to that point doesn't appear to be worth the hassle so why bother.
|
| 1426.160 | No room to smile or laugh??. | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Thu Nov 04 1993 16:13 | 41 |
| Is there no room for humor any more?. I just re-read the previous notes and
saw no attack on Jim, Dr. Shaw or electrics.
There seems to be a national and corporate malaise these days. It was
highlighted to me by my kids over Halloween. There was much debate about
what was acceptable as a costume. It seems that impersonating a one armed
character could be construed as offensive to a person with a missing limb.
Similarly Pirates were out, due to the one eye issue that could also be
offensive. My youngest suggested that we all go as headless monsters
because she didn't know any people without heads! :-)
Certainly an electric pilot and plane would be welcome at any field where I
am flying. Ask Hartmut who was launching his electric plane when he visited
America.
This notes files allows you and anyone else to express your/their interest
and liking of electric planes. Equally it allows me to do the opposite.
Please also note that Bernd and Harmut do not have English as their
first language. Although they write very well, they sometimes chose
words that are stronger to us than they were to the intended translation
of the authors.
The DECRCM file is for local chit-chat and people with thick skins and
great senses of humor. It is a separate file for two main reasons,
a) Because notes file purists in the past objected to the purile
contributions of many of the local, read New England "jokers", to the
RC notes file.
b) Because the old file was too huge and would not allow itself to be
archived.
Fore a long time I wrote in the RC file. Then I too became offended and
only wrote in the DECRCM. Then Al Ryder left so I started writing in RC
notes again. Now once again we have a noter over-reacting. I guess
it's just abrasive old me doing it again?. :-(
Regards,
EVL-L Eric.
|
| 1426.161 | Let's Enjoy Our File | LEDS::WATT | | Thu Nov 04 1993 17:20 | 10 |
| Anyone who knows Eric knows that he "Hates" most things. :-) The file
has been pretty quiet as of late for a variety of reasons and there's
nothing like a little verbal battle to get more dialog going. A
differing opinion should not be taken as a personal attack. On top of
that we have to be careful not to offend each other. Bottom line is
that it should be FUN to participate in this file. I do RC for fun and
fun alone.
Charlie
|
| 1426.162 | Let's keep this string going and the information flowing | KBOMFG::KLINGENBERG | | Fri Nov 05 1993 10:22 | 63 |
| Uh oh,, I only have to take a day off and leave you alone, and what
happens? Can't believe it!
Sorry I didn't respond earlier. We went to the Modellbau Sued in
Stuttgart yesterday, a fair maybe similar to your WRAM show. And, in
fact, the trip was inspired by your WRAM show trip repots (in the
notesfile) many moons ago. Bernd, myself and two more buddies. Hope
we'll find the time to enter a report soon. We also met Joe T. there.
I understand there were a couple statement in here that simply are not
true. I can attest to the hosti... no, hospitality of the HTA crew. I
went to CMRCM as often as I could last year, and I was welcomed. The
only kind of planes I had with me were electrics and people were
curious about them and very interested, helpful and caring. Even Eric
accepted when I did not give in to his temptations to try aerobatics
with the Kormoran canard that I was not capable of and maybe neither
was the plane. I also resisted to hand him the tranny - and we are
still friends (I hope 8-). I guess that during the time I owned the
Race Cat, Bernd threw it at least twice as much as I did.
I was very happy the way I was treated within DECRCM, and I was glad to
put faces to names during that time last year. I was especially glad
that I had a chance to meet you, Jim B., in person. You took some
effort to see me in Rochester NY, and I think I can say it was worth it
- at least for me it was. It would never have happened without sharing
our common interest in this notesfile.
It's simply not true that noone cares about your entries. At least I
do. And I share my experience and views, also. I would like to ask you
to keep entering what you find at least for the months I will remain with
Digital. And maybe others can fill in on my place then.
I don't think we'll convert anyone to electrics by articles like the
one of Keith Shaw. People get interested by what they see. And I know a
few who got interested in my Race Cat when I flew it in Massachusetts
last year. Maybe a few would have been built if I would have exposed
them to it more often:-)
I guess we will have to accept that people focus on different things.
About 4 years ago I have decided that for the type of flying I intend
to do, I will not start with glo-glop again. This decision has not
changed a bit since. I have seen many nice glo planes fly in the
meantime, I have seen people crank their engines unsuccessfully for the
whole 2 hours I was at the field (and got 6 flights in that time), it's
just not for me. Maybe _IF_ RC becomes a hobby for our son, I might go
glo again, but that's a big maybe and a big if.
I've seen Gremlins fly and even got a chance (in fact at least two) for
some stick time on Charlie's. It's a nice plane, I just don't get
bitten by the bug. I can't imagine putting even the little time and
money requested into such a kind of plane. I don't like the looks, and
I don't think I'd like to combat. I wouldn't spend a day watching a
Gremlin combat, but I liked to see them fly at the field.
Jim, I'd like to see you back in here. I know I'll miss this conference
(and DECRCM, too!!) once I'll be gone, but let's keep it going with
it's diversity as long as we can.
I guess I rambled enough, I'll talk about that 100" electric Spitfire
in a different note. If there is enough interest8-)...
Best regards,
Hartmut
|
| 1426.163 | Are you kidding? | BAHTAT::EATON_N | Smile when you say that! | Fri Nov 05 1993 10:28 | 12 |
|
> I'll talk about that 100" electric Spitfire in a different note.
If there is enough interest8-)...
TWANG!!!!!
This is the sound of the line tightening as Nigel bites......
Come on Hartmut, you're not getting away with that one! 8^) Yes please,
can we have some details?
Nigel
|
| 1426.164 | Okay, here goes (I'll do with only one member showing interest:-) | KBOMFG::KLINGENBERG | | Fri Nov 05 1993 11:52 | 54 |
| One of the booths we were at yesterday was of Andreas Gietz. Some of
you may recall that I rambled about his gorgeous DC 3 a long time ago
when I saw it at the Woerishofen scale contest.
Now he has a business (Fiber classics) and offers full composite scale
kits (so far said DC 3, a Yak 55 (I think) and the Spitfire). Tom
Percuoco, Nick, are you listening?
Andreas Gietz also picked up the distribution for Fiberglassfluegel
unlimited, one of the best suppliers for full composite scale gliders.
He had one Spitfire at the booth, and it was one of the most amazing
scale planes I've ever seen. It not only showed every panel and every
rivet, but some panels showed dents also. It was painted in camouflage
with chips missing and dirt coming up from the panel seams. Just
awesome. You get this plane as a full composite kit (fibreglass
fuselage and wings) with all rivets, panels and dents from fiber
classics. The plane has a wingspan of 100".
Now Joe T. mentioned he had seen one of these fly electric. Seems
Andreas Gietz overheard us, came by and said: "This is the one!" He
went on and showed us where the motors sit and where the batteries go.
The plane is drive by 2 top-of-the-line Hektoplett motors working with
toothbelts on one shaft (gear reduction). An additional Speed 400 motor
with fan is used to cool the Hektopletts. Each of the Hektopletts is
run on 30 cells and it's own controller. Many have claimed it would
never work, but it does.
Gietz said that when you do the startup run, this electric is far
quicker than the same plane on a Zenoah ZG62! It has more power! Now,
admittedly, as soon as it has some ground speed, the load on the prop
will drop as will the current, and the ZG62 powered plane has more
power during horizontal flight. But once you're going up (asking for
torque), the electric will be at least even again.
The plane is equipped with retractable gear and anything you'd ask for
in a scale plane.
Of course, noise is an issue. Electric fans go crazy by the sound (just
the prop, of course), glow fans turn their back... Sorry, I don't
recall prop size and rpm, maybe Bernd can fill in.
Again, this is not everyone's plane. I can't imagine putting the time
and effort necessary for a scale ship in, and even if I did, I guess
I'd prefer a gas engine over buying 2 top-of-the-line electric motors,
60 cells, 2 controllers, 2 quick chargers that can do 30 cells each
etc. And flight time is still limited to around 5 minutes. But it's
amazing to see what can be done. And as soon as batteies break through
(I'm with you, Charlie!)...
Best regards,
Hartmut
|
| 1426.165 | And the weight is... | KBOMFG::KLINGENBERG | | Fri Nov 05 1993 11:59 | 1 |
| Oh, I forgot the all up weight: 35.3 lbs (~ 7 lbs batteries)
|
| 1426.166 | Very interesting.... | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Fri Nov 05 1993 12:10 | 13 |
| I talked to Andreas at the 1993 Top Gun event in West palm beach. His
canopy was pitched next to mine, (Read Charlie Nelsons). I watched them
put together the Dakota and the Spit. I have video of him flying the
twin.
They were a very busy team.
Regards,
Eric..
P.S. Tell us more about the show pleeeeaaasseee...
|
| 1426.167 | My assessment | UNYEM::BLUMJ | | Fri Nov 05 1993 20:09 | 49 |
| Now that I am no longer angry, I know what was so upsetting. Basically
Bernd, Charlie and I were talking about converting electric models
to glow power(notes .120-.128). This is kind of novel because in
electric circles much discussion on doing the opposite(glo to electric)
is common.
I questioned whether the airframes of models designed for electric
power were suitable for glow engines. The term "lead sled" was
used in refering to electric powered planes.
Wanting to discuss this idea, I authored note .129 entitled "Lead
Sleds examined".
>While I agree many electrics certainly qualify as "lead sleds", I
>thought I would provide details of Keith Shaw's Electric Scale
>Airforce:
The note concluded with an invitation to provide glow powered
equivalent examples as follows:
>What I would be interested in knowing is how these ships compare
>to their glo powered equivalent in terms of weight/wingloading.
>Can anyone provide any comparisons(real life preferred, not
>manufacturers specs as these always seem on the light side in my
>experience?
I then authored note .131 which was a reprint of Shaw's MAN article,
giving the philosophy, flying style and building methods that resulted
in the creation of the airplanes detailed in note .129.
Well nobody provided any information about weights/wingloadings of
glow airplanes so we could discuss this "lead sled" electric idea.
And nobody disagreed with any of Shaw's ideas specifically. Rather,
what I perceived as a general attack on Shaw and electric flight in
general ensued. Stuff like "This isn't even worth reading", "electric
sucks", etc.
OK I probably over reacted, BUT how about being a little more specific
in the criticism. I think the original "intelligent" discussion of
glow/electric airframe design deteriorated into an electric bashing
session.
So if anybody wants to get back to where we were at .129, I look
forward to some information.
Regards,
Jim
|
| 1426.168 | Back on Track | LEDS::WATT | | Fri Nov 05 1993 20:22 | 13 |
| Jim,
It seems to me that the larger electric scale planes would be
pretty good. The percent weight of the power system probably stays
reasonable and most scale planes don't need awsome power to fly scale
like. The small electrics that have 05 motors have a power system that
weighs as much as the airframe. (At least my Electrostreak does) I
have never seen the larger electrics fly but I bet they are nice.
Charlie
P. S. I'm glad you are no longer angry. :-)
|
| 1426.169 | appologies, Mr.Electric ! | KBOMFG::KNOERLE | | Mon Nov 08 1993 07:17 | 139 |
| Sorry for answering somewhat too late. I didn't get a chance to look into
the notes file on Friday.
Sorry, Jim, my reply was never meant to attack you !!!!! My reply was only
towards the content of your note, not to the note itself or the entry of it.
I might have been overreacting and choose the wrong words. I was on the run
when I read this article and just had to enter a reply since I was frustrated
of Mr. Shaws view on this side of the hobby (combustion chamber engines).
Hartmut and others know that I really accept ALL aspects of our hobby and
that I would have and Electric plane already if the initial costs would
not be as they are.
The reason why I used the words I used is simply because Mr. Shaw cannot say
this as common truth.
"An unreliable power system is the most common frustration that defeats
would be modelers. With electric power, there is no cranking a balky
engine, fiddling with needle valves too near a whirlin meat slicer,
unreliable idles or blown glow plugs. Gone are the worries of tank
location, pinholes in fuel lines, structural degradation from oil
soaking, vibration induced radio failures and equipment aging.
I know more reliable running engines that nonreliably running engines. My
Webra 61 Longstroke never quit inflight, has perfect idle and used two glow
plugs in three years. Total flight time estimated 40 hours (80-100 litres fuel)
Ask Charly, Eric and all others. He might be right for small engines like COX
and similar. Look at Charlies Ultra Sport, my Knife edge and many others : NO
oil soaking. My exhaust exit is underneath the back of the fuse, the gases won't
reach the fuse.
Instead you just position your plane on the taxiway, advance the "throttle",
taxi out and take off. the power from an electric is so reproducible
that if you can do a 20-maneuver aerobatic routine when the plane is
new, five years later, you will still be able to do the same routine,
summer or winter, rain or shine.
We all do the same. The engines won't change either. Will Keith's batteries
last 5 years ?
"From an aesthetic(and aerodynamic) standpoint, the awkward
model-engine cylinder, muffler and plumbing spoil the look of a clean
sport model or a painstakingly detailed scale model. With electric
power, a clean, streamlined nose or exact scale cowl is easily done."
I know many models with fully enclosed engines & mufflers. As examples look at
the Pattern planes, Pitts, Caps, Cups, and many others. As he writes, Engines
with mufflers generally spoil the looks of sleek planes. I admitt, that an
electric motor is easier to install aerodynamicaly clean. But a Pitts is a
Pitts.
"Many projects that are usually considered tough or impossible become
easy, or at least feasible. Twins and multi-motored aircraft are
almost trivial, as problems of synchronization, single engine failures,
cramped nacelles, and structural nightmares are nonexistent.
I've seen multiengines planes with very reliable engines. However, electrics
seem to be naturally better suited.
Pusher configurations invariably suffer the problems of overheating, fuel
flow, muffler interference and balance. When using electric power,
only a small motor would be mounted in the tail, while the battery
pack is positioned in the nose, eliminating the need to add lead to
get the correct balance. There would be no need for pusher props
as most electric motors can be made to run in either direction. The
easy addition to gearboxes enables an electric motor to turn very
large, efficient props with modest horsepower.
A friend of mine flies a mini F16 with an OS25FP in Pusher configuration. Boy
he has a performance really awsome. And landings are incredible. High angle
of attack. The plane's weight is (I guess) around 800 grams. Immagine an
additional 500 grams for Nicads and Motor. The flying would not be as it is.
Again, no overheating, fuel problems or other.
Many scale models of radial-engine aircraft do not need extreme levels
of horsepower, just a sensible amount efficiently coupled into a propeller
large enough to clear the cowl. With glow power, a grossly oversize engine
engine is needed just to get a little bit of the prop beyond the edge
of the cowl."
Cannot agree. A real big plane needs a big engine.
"One of the real advantages of electrics is the efficient, accurate
control of power. Since good motors can stand very high powers for
short times, the plane can be propped for the highest power demand,
such as vertical roll or vertical 8, and flown at reduced power for
the remainder of the flight.
Same true with combustion engines.
"Invest in good equipment. Trying to get away with cheap car motors,
old questionable ni-cads or an oil soaked glow airframe are ways of
guaranteeing failure. Finally- practice,practice,practice! While
virtually everyone will imagine I'm talking about 8 point rolls or
Lomcevaks, it is important to learn to land correctly every flight.
Careful landings dramtaically reduce the structural loads and weight
requirements of the airframe. 50% of the weight in a typical glow
powered kit is just there to allow it to survive the occasional
"hard landing". You've seen them: the pilot lands about 3 feet high,
the plane stalls, drops a wing tip, cartwheels two or three times,
flips end over end on its back. And the pilot is really mad that he
broke another @#%!prop! Once the hard landing barrier has been
overcome, the structural weight can be reduced to a point where the
total flying weight may actually be lighter than a glow plane of
similar performance, while maintianing every bit of aerodynamic
strength. Learning to fly efficiently will also improve the
performance and extend your flight time. Thee single most power-
consuming maneuver is gaining altitude.
What's the point ? True in every aspect of our hobby.
Random climbing and diving or "horsing" the plane around the sky will
lead to shorter flights.
This is fun ! :-)
Climb to a comfortable altitude and base your aerobatics and circuits
relative to this reference line. Smooth flying, rudder finesse and power
management can easily double your flight times."
Same true for Gas engines and gliders particularily.
All, do you get my point ? This is why I was upset. In my RC world Things are
not one way OR the other. There are MANY ways and I accept all (well almost).
I don't like too loud engines, guys flying dangerously and stuff like this.
And if one fingerpoints to one groupe I'll shoot back. Again, I didn't meant
any person in this conference nor the entry of this writing, even not this
Keith Shaw. Just what he wrote.
Aeh, btw, the Spitfire's prop is a 24 x 16 spinning above 4000 rpm static !
More trust than a ZG62. And truely awesome. Would like to hear the sound of
this warbird : brrrrmmmmmmmmm Hahahahahhihihihi ! :-) :-) :-) :-) :-)
Please continue, Jim. I always read your entries. See the bright side :
40 entries in 3 days, not bad ! :-)
Bernd
|
| 1426.170 | Random Comments on RC | LEDS::WATT | | Mon Nov 08 1993 10:53 | 28 |
| Bernd,
I have to agree with you - and some of the generalizations upset me
also. Keith Shaw is an "Expert" in the Electric field so it seems
simple to him but I've had guys show up at our field with electrics
that I couldn't fly and ask for instruction. (Same with gas jobs)
"Balky engines" are the sure sign of a beginner that needs training on
how to operate an engine. All modern engines will run reliably if you
have the proper fuel, glow plug, tank installation, and the knowledge
of how to set the mixture. Electrics need proper electrical
connections to run properly and reliably. I've seen melted connections
on bad installations. While it is true that IC engines do wear out in
time (quickly if you don't run them right) the batteries and brushes
also wear out on an electric. I'd bet that many of Keith's larger
electrics have battery packs that cost close to $80 or more - and I'm
sure that he uses his expertise to take good care of them. Bad
charging practice can ruin a pack in no time.
My point is that to succeed in any aspect of
this hobby, you need to learn how to do it right. There's no "easy"
way to get flying as a beginner.
The great thing about RC is that there is tremendous room for
experimentation and variety in airframes and in power systems. Some
like to noodle around the sky and others like to hotdog at full power.
Charlie
|
| 1426.171 | Your points are well taken | UNYEM::BLUMJ | | Mon Nov 08 1993 13:31 | 74 |
| Charlie/Bernd,
Your comments in .168-.170 are well founded and generally
make sense to me as a flyer "pushing electric flight." Keith Shaw also
is definitely "pushing electric flight". This may not have been clear
in .131. His articles are always "biased" towards electric flight.
What I mean by "pushing electric flight" is this - Shaw, myself and
others tried electric flight and liked it, seeing some things that
we preferred over glow engine flight, we are presenting it as a
viable alternative to glow flight. Our arguments are thus biased
towards electric's strong points. Hence Shaw's article should not
be construed as having "The pluses and minuses of electric flight"
as its main theme. He believes in electrics and makes this perfectly
clear.
Being outnumbered by wet flyers probably 100-to-1(conservative
guesstimate!) electric flyers perceive(maybe falsely) that they must
"justify" flying electric models. The "electric community" feels that
a lot of misconceptions and outwardly false ideas are held by many
glow fliers. Some that I have personally heard include:
- Electrics don't fly
- Electrics are too heavy("lead sleds")to fly well.
- While a carefully designed electric might fly, electric power
is not viable for helicopters, ducted fans jets, WWII scale
models,etc.
I can relate an interesting story from my own club. Last year I built
a Robbe Arcus and flew it alone at my "glider fields". This was fun
but lonely(I enjoy the modeling camerardie-wet and dry!). So I decided
to go to the local field to see if I could become a member. I showed
up with the Arcus on Thursday night and was allowed to join. I even
flew the plane once. Several members were surpsrised to see the climb
rate and fast flying characteristics of the Arcus. Anyway I showed up
the next Thursday night and as I was putting the Arcus together, a man
who I later learned was one of the club's instructors, told several
other members(who had seen the Arcus fly the week before) that this
type of plane - "Does not fly well". I launched the Arcus and climbed
to altitude where after cruising for a few moments, I set up for a
high speed pass by diving at about 45 degrees. The instuctor announced
to the observing members- "There look at that, I told you it wouldn't
fly well." Dave, who had seen me fly a week earlier replied - "Herman,
he is doing that on purpose!" I found it hard to believe that Herman
actually thought the Arcus flew this way(45 degrees downward)! I also
am frequently asked by some members if I plan on "moving up" to one of the
typical gas models they fly(Falcon 56, Ace Bingo, Sig Seniorita, etc.)
As I sit there with $1000 invested in a plane(Surpsise II) designed by
the 4 time world champion(Rudolph Freudenthaler) capable of vertical
climb(nearly 6000 ft/min) and speeds of probably 150 mph, with flight
times no less than 8 minutes(great L/D), and OK glider style
aerobatics, I am not sure what they mean by "moving up" to a Falcon 56!
Anyway it is not all that hard to become "defensive" as an electric
flyer(especially an electric glider)! I need to try and not carry
these past experiences into my discourse in this notes file. For
the most part the contributors here have had a heck of a lot more
"interest" than at my club.
Gotta go, but I will be addressing what I feel are relavent points
in Shaw's article.
I appreciate the replies and enjoy the "technical side" of our
occasionally heated discussions. I continue to learn and see other
points of view.
Regards,
Jim
|
| 1426.172 | friends again ? :-) | KBOMFG::KNOERLE | | Mon Nov 08 1993 14:30 | 12 |
|
In our place the ratio WET to DRY is about 1 : 1 if you count those
flying both. I'd also guess that every 2nd power modeler flies
WET & DRY, and every 2nd modeler flies power and nonpower. Maybe every
20th flies chopper.
BTW, regarding wing loading after conversion : The electric Race Cat
had a wing loading of approx. 23.3 ounces/feet^2 , the IC engine
version now has a wing loading of approx. 15 ounces/feet^2.
Bernd
|
| 1426.173 | FP's scrape when pushed | KAY::FISHER | A watched pack never peaks. | Mon Nov 08 1993 14:33 | 22 |
| > <<< Note 1426.169 by KBOMFG::KNOERLE >>>
> -< appologies, Mr.Electric ! >-
...
>A friend of mine flies a mini F16 with an OS25FP in Pusher configuration. Boy
>he has a performance really awsome. And landings are incredible. High angle
...
Bernd, If it is a 25SF or FSR OK but if it really is a 25 FP you should warn
your friend. The Non-ball bearing OS engines will chafe the backplate
if used in a pusher configuration. I've been tempted to a pusher a couple
of times in the past and couldn't because it would have involved using
OS FP engines. Experts please correct me if I am wrong but I don't think
you should ever user a "OS25FP in Pusher configuration".
Bye --+--
Kay R. Fisher |
---------------O---------------
################################################################################
|
| 1426.174 | Airframe weight - glow/electric | UNYEM::BLUMJ | | Mon Nov 08 1993 15:52 | 77 |
| I will attempt to summarize Keith Shaw's ideas on model construction
as they relate to electric power. In a nutshell his philosophy is
that most glow engine powered planes are "overbuilt"(ie too heavy).
His feeling is if a pilot learns to land reliably an airframe
can be built much lighter because the extra material to absorb the
hard landing stress can be minimized.
I would readily agree that glow powered models provide the opportunity
to practice more landings in a given flying session owing to the longer
run time. Indeed Shaw himself learned to fly R/C with glow models.
His next point is that glow engines vibrate quite a bit, requiring
additional airframe bulk to handle this stress.
I would like to know specifically what you guys think about these
two points. I don't have the empirical knowledge of glow airplanes
to know if Shaw is off-base here. It is tempting to believe him
because his planes seem to fly quite well. I will not consider
Shaw's statements fact until I hear "from the other side."
Owing to the lack of data provided thus far, I will provide weight
information from manufacturers specs. I can not attest to the
empirical accuracy of these numbers, with the exception of Al Casey's
Mig-3 which he talks about in note 271.74. The numbers came from
the new Tower Catalog.
Plane Manufacturer Wingspan/area Weight Wingloading
********** ************ ******** ****** ***********
Mig-3 Al Casey 72.75" 11.5 lbs(wet) 27oz/sq ft
P-51 Royal 777 sq in 8-11 lbs 24-33" "
P-51 Pica 74"(950) 12-14 lbs 29-34" "
Spitfire Royal 64"-736 7-9 lbs. 22-28" "
Spitfire Pica 65"-714 7-8 lbs. 22-26" "
*I am getting sick of typing, it appears that most of the planes from
other manufacturers are around these weights.
It appears that Shaw's scale planes(see data in .129) are of comparable
weight to what is available in glow powered kits of similar planes. In
fact his planes appear to be on the light side of what the
manufacturers are quoting. BTW his planes are good scale renditions,
being true in outline, having retracts, pilots, flaps, etc. Al's
Mig-3 certainly is finished in true award winning scale fashion(ie
light fiberglass and paint). As he states in 271.74 this added 14 oz.
of weight to his plane. So the Mig-3 in monokote would be about 10 oz.
lighter.
Tony Fiore whose 1/5 Scale Pica Mustang has flown the last two years
at KRC on an Astro 90 with 40 cells weighs 22.5 lbs! The manufacturers
spec for this plane is 15-18 lbs. Tony built this kit without
modification(ie with the kit supplied wood by the plan) as a test bed
for the Astro 90. It has Robart 1/4 scale retracts. This would
tend to lend credibility to Shaw's argument, as his 1/4 scale Percival
Mew Gull at 75" span weighs 10.25 lbs. Using Shaw's building
techniques, they agree that the plan could be built at around 16 lbs.
BTW the mustang flies quite well even at 22.5 lbs!
Shaw's building techniques are not exotic(no composites) using ply,
balsa, and monokote these should be familiar to all traditional
modelers. His "secret" is he knows where a plane needs to be strong
and how strong it needs to be. This coupled with his ability to
land reliably works for him. In defense of the glow ships, Shaw's
planes fly at scale like speeds. His 1/7 scale Spitfire does 60 mph
which is probably a lot less than a .60 glow Spit would fly.
No kits exist for Shaw's models. He scales them up from 3 -views
and then engineers them for the motors/batteries to be used.
Are the typical glow powered planes overbuilt, or are they properly
matched to the induced stresses?
Regards,
Jim
|
| 1426.175 | Crashability is a reasonable goal too... | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Mon Nov 08 1993 16:20 | 18 |
| One thing in favor of keeping a little extra meat on the glow plane
bones is that it allows you to fly in less than ideal conditions. I'm
generally at the field with 15mph winds and sometimes have a bad
landing due to the rotor at the end of the field and get pushed down
onto the runway. The beefier airframe will take this abuse. A lighter
airframe would probably need some repairs under those conditions.
There are a lot of times when I can't pick the day/conditions to fly
in and I need to have a durable plane to meet the challenges of the
time allowed. The Gremlin has stood up well in this situation. I
always seem to be banging into the ground recently.
> Are the typical glow powered planes overbuilt, or are they properly
> matched to the induced stresses?
Depends on what you expect to have for "induced stresses"
Yes, it's true that I'm building to crash but I seem to be better able
to fly after an incident too.
|
| 1426.176 | Test pilot needed | UNYEM::BLUMJ | | Mon Nov 08 1993 16:36 | 33 |
| RE: .172
Bernd,
Glad to be your friend! I wish you were available to do the
test hop on my rapidly progressing Cad-Cat(basically a Race cat with
less wing area approx 180 sq in and thicker airfoil HQ1/8).
I put the 6.5x6.5 Graupner Speed prop on my Astro 05 FAI last night
on the test stand. With 7 cells, initial RPM=13,200 at 30 amp draw.
As this thing is spinning furiously away, I glance at the tiny
fuselage and wings and the reality of flying this thing is starting
to set in.
It was easy to cajol Hartmut, but now that its my turn, I am scared
to fly this thing! My past experince tells me if you do not step
up to the flight line with great confidence, you already have greatly
diminished your chances for success.
Will test the motor I got from Hartmut tonight(Speed 500 with 6x6
Graupner folding prop).
BTW the Astro 5 turn 05 Fai motor is reported to turn a 6x6 prop
at 17,000 RPM.
By starting with 1000 mah cells, the weight will drop 3 oz. over
the 1400 mah. Right now I don't care about runtime- whatever it is
will exceed my nerves!
Regards,
Jim
|
| 1426.177 | ESC???. | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Mon Nov 08 1993 16:51 | 11 |
| OK Reith,
when are we going to see an electric Gremlin???.
You could even use round pipe???.
Regards,
EVL-1.
|
| 1426.178 | Now where'd I put than "spare time"? | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Mon Nov 08 1993 16:56 | 1 |
| Sooner than you think (I need to buy some 1000mah batteries for it 8^)
|
| 1426.179 | No cure ... | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Mon Nov 08 1993 17:20 | 5 |
| >>Sooner than you think (I need to buy some 1000mah batteries for it 8^)
And a pilot with an "ohming device! :-)
E.
|
| 1426.181 | some hints regarding any_cat | KBOMFG::KNOERLE | | Tue Nov 09 1993 07:19 | 48 |
|
>>> I wish you were available to do the test hop on my rapidly progressing
>>> Cad-Cat(basically a Race cat with less wing area approx 180 sq in and
>>> thicker airfoil HQ1/8).
Hey Jim, I'd be glad to assist, just send me that ticket via UPS, should
be here in no time ! One point to consider : as per Hartmut the electric
version weighted 950 grams with a resulting wing loading of 66 grams/dm^2.
If your wing area dropped down to 11.6 dm^2 (180 sq in) your weight should
be below 650 grams (23 ounces) for similar landing performance.
One other point, your thicker airfoil (8%) will probably decrease the top
end speed somewhat.
The first throw you have to have someone knowing how to throw a plane. Level
with a bit upward and a good throw !
>>> I put the 6.5x6.5 Graupner Speed prop on my Astro 05 FAI last night
>>> on the test stand. With 7 cells, initial RPM=13,200 at 30 amp draw.
>>> As this thing is spinning furiously away, I glance at the tiny
>>> fuselage and wings and the reality of flying this thing is starting
>>> to set in.
This rev numbers are good ! The plane will accelerate like hell once
airborne. And very important : don't use large throws ! The thing will be
uncontrolable ! The first flight I did the control throws where way to big and
it was 10 handfull and shaking knees with 12 on the Richter Scale at least.
>>> It was easy to cajol Hartmut, but now that its my turn, I am scared
>>> to fly this thing! My past experince tells me if you do not step
>>> up to the flight line with great confidence, you already have greatly
>>> diminished your chances for success.
Have an experienced flyer assist you. Even if just calming you down by saying
stuff like "watchit, hell, damm fast, attention....!" and other nerv calming
things. Once trimmed it flies like on rails.
>>> Will test the motor I got from Hartmut tonight(Speed 500 with 6x6
>>> Graupner folding prop).
>>> BTW the Astro 5 turn 05 Fai motor is reported to turn a 6x6 prop
>>> at 17,000 RPM.
more than enough. - Bernd
Oh, btw, knowing that Hartmut's version the fuse always cracket behind the
wings I glued to rails 1/8 x 1/4 inch lengthwise to the fuselage sides.
The advantage is to be able to glue the servoboard to them giving a closed box
construction of the fuse. Maybe not possible with Nicads.
|
| 1426.182 | Empirical 05 motor tests | UNYEM::BLUMJ | | Thu Nov 11 1993 16:05 | 9 |
| I retested the Astro 05 FAI with the 7 cell pack taken right
of the peak charger, the previous test was conducted with
the pack having a 2 week old charge:
Astro 05 w/ 6.5x6.5 Speed prop = 14,300 RPM (32 AMPS)
Graupner Speed 500 w/ Graupner 6x6 folding prop = 13,500 RPM @ 30 amps
|