[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

386.0. "F3E --- competitive, multi-task electric" by VARESE::SIEGMANN () Mon Dec 17 1990 11:52

Ciao a Tutti; 

Not sure where to place this update note but here it is for 'moderating'
pleasure... 

This is an update ( due to some prompting by Hartmut..) on my recent foray into
the world of electrics, airfoils, props and hi-tec construction of F3E &
unlimited type machines, as well as some work on motor-gliders as; as seen
from Italy. I'll attempt to keep this simple and somewhat structured, although
this does go against the grain here...

I have been experimenting, along with a few of the people here, with various
combinations of airfoils, motors and props plus construction practices with the
aim of achieving.. well, I'm not sure what. I suppose 'optimum performance' 
is as close as anything. Not very scientific I know, but it does give one
an excuse to build and tinker and discuss (and it has certainly helped at
least my technical Italian..) and fulfill my need to exercise 'the other side'
of my brain. 

There are so many variables to consider that I won't even attempt to try
enumerating. Suffice to give some idea of where I am today and then what is
competitive in the euro-int'l theater and provide a basis for others to begin
their own experimenting and flying. I am not at all F3E competitive and don't
really know the rules (in English or Italian) so perhaps someone can fill us
in here. I just fell into this area because several of the people in the club
here are very competitive in these events and so I take advantage of this
knowledge and leverage a bit. I, on the other hand, love to work in, and know,
wood; albeit from the standpoint of full size boat building but wood-is-wood
and this knowledge is something I have been able to build upon, incorporate
into the area of wing design and construction and pass on to the people here in
Italy. 

Basically (very..) F3E is electrics, coupled with high speed gliding, coupled
with duration, coupled with precision landings... Here there seem to be two
main categories, based on # of cells: the 10 cell and the fit-as-many-cells-as-
possible categories. Wings seem to be maxed out around 2 mtrs with the trend
getting a bit shorter to 1.85 or so. Since the tasks are varied there is no
one best answer but, like life, many trade-offs in optimization of the overall
characteristics of the machine. And they really are machines. Minimum motor
runs, max speed, battery choice, thermalling, precise landings.... jeeze..
The planes are also VERY aerobatic, both with and without power.


Wings\airfoils:
---------------

Presently mine is a now-popular airfoil; the RG15 with a 10% thickness ratio.
This is a FAST arifoil but it also can be slowed down and actually thermal a
bit. It is 2 mtrs and foam core (cut by a club member) with internal micro
servos for ailerons, sheeted with 1mm hard balsa. The  dihedral is 6 deg. The
construction, over foam, includes the use of carbon fiber under the balsa (6
lengths top/bottom, staggered in length towards the extremities). The balsa is,
as usual, sheeted up first and then sealed with dope (no, no...not THAT kind..)
before the epoxy is applied to the sheet. For the joining of the two halves I
fabricated a joiner of 25 cm x 1 cm out of a piece of oak. I had some oak
pieces left over from a boat project and the grain happened to be grown at 6
deg, hence the dihedral.. which was tapered and then had carbon fiber top &
bottom and let into the wing halves and joined with the longeroni, uh , main
spar, uh, well anyway the thing that goes the length of the wing to control
bending. This was also made from a straight piece of oak (spruce would have
been lighter for the weight/strength but could not come up with any on a sunday
evening when I was doing this..) tapered towards the outboard end. It is quite
thin, about 2mm and a bit more than 1 cm thick. This was let into a slot in the
foam and epoxied in place. Carbon fiber over the top/bottom of this spar to
make an I-beam. The C-F is the stuff you can buy from Tower; .5cm x .5 mm (+-).
Each half of the wing ended with a 1mm piece of ply. This was planed down to
make the dihedral and joined with epoxy, in addition to the aformentioned oak
joiner. The center section for about 15 cm each side was then covered with very
light glass fiber and a second, narrower piece, epoxied at the center. This
makes for a strong joint. So far I have not been able to fold this wing; the
people here say I just haven't tried hard enough...

Controls are ailerons and, when (if) I get my new X-347, flap/aileron combo.
The flaperons are really a necessity for competition.

All-up weight wing; 450 gms. 

Total weight of plane, batteries, motor etc: 2 kg.

Incidently, this machine makes an excellent slope-er when you remove the
motor and batteries!

Other airfoils tried are: SD3021 (for large electric gliders), Clark-Y for
slopes, E387 (nice for aerobatics/fast+slow large span gliders w or w/o
electric, and the venerable E205 for thermals and slope. 

I like wings...

Fuselage:
---------

Mome made of fiberglass reinforced with C-F ribbon. Top mounted stabilizer
with micro servo in the vertical stab. No rudder. Top mounting for the wing
via 6mm (front) and 4mm nylon bolts into ply member with inbedded metal nut.
Round section, except for the wing mounting. Reinforcement with C-F at
mounting points for wing, motor, stab and at the vertical stab connection.

Weight 130 gms.

Motors:
-------

Presently running a Keller 40/10 (Thanks to Hartmut!) with 12, 900mAh SCR.
Also use 14, 1200mAh pack for startling performance but a bit on the heavy
side, making landings hot and exciting...

With the 12 cell setup I get 5-6 climb-outs. Haven't timed these but about
30 secs each gets it high enough to make visibility/orientation an issue.

With the 14 cell setup I get the 7 climb-outs, less than 30 secs each and
faster for sure. 

With either of these set-ups I can probably rip off the wings if I try...
without motor; just due to the extreme speed and responsiveness of these
models. This is the main way of 'testing' various wing construction
techniques.... 

Haven't tried the Astro-C 40 yet but a friend is building a machine and will
install one I purchased. This takes 18, 900mAh cells so may not be too
competitive. We'll see...

The 'PROS', in the unlimited class, use Astro-C 60 (!) with 24+, 1200mAh cells!!
Or Hectoplett 335 (mumble...) motors with ? cells. These are the most expensive
motors, hence the interest and use by the Swiss (who hold the int'l record..).
Hartmut, you have any access to these...? ;-)

Props:
------

Home made. Epoxy/C-F high-speed profile. Folding. Use several different sizes.
Presently using a 32 x 15 (12.6 x 6) tapered for the 12 cell setup. This is
another art and the fellow mking them at the club also make them for the
Italian champions in electrics. Uses female molds and carbon roving. We
trade...

Battery:
--------

SCR. 900mAh and 1200 mAh. Sanyo.
For the flight pack using a 200mAh 4 cell battery.

Misc:
-----

Speed controller is a Schalter 40 A on/off/brake. Very light, robust.

Servos are all the Futaba S133.

Connectors are heavy duty male/female gold from Robbe (when I can find them..)

Not much paint anywhere. Just enough at strategic places to tell if I am
inverted, coming/going, etc... Too heavy. The fuselage does have integral
coloring.
    
T.RTitleUserPersonal
Name
DateLines
386.2Report on demo of F3E and solar powered planesKBOMFG::KLINGENBERGMon Jan 08 1990 15:5686
        Here finally comes a report of the electric models Franz Weissgerber
        brought with him to the demo of GRAUPNER/JR in Kempten (for RC report,
        look at #737).

        I really don't know where to start. Don't hesitate to ask further 
        questions if you're interested.

        1.) The first model displayed was the ARIANE 5. Ariane is the name
        of the line of Franz Weissgerbers F3E models, it's the 5th iteration.
        It's controlled with aileron, flaps, elevator and motor controller,
        all of which are mixed by the TX's software. Flaps and motor controller
        are controlled by three-point switches with positions for distance, 
        speed and landing (flaps) and motor off/half speed/full speed (this
        one only to save the motor and the folding prop.

        Motor is a Plettenberg cobalt or GRAUPNER ULTRA 2000 (about DM 500,-
        $ 280.- in Germany), driven by 27 SANYO 900 SCR cells. Notice that
        they push the voltage up to keep the current limited.

        The plane is built from glass and carbon reinforced epoxy, and I 
        did not see any foam! The wing (2 m span) has a bar made of glass 
	and carbon, no foam. It is incredibly light and strong. The control 
	surfaces don't have conventional hinges, but their upper surface is 
	laminated into the wing! No gap, no step. On the bottom, you see that 
	the leading edge of the control surfaces has a radius to keep the gap
        between rudder and wing as small as possible.

        Building technique is similar to that of full size airplanes in
        negative molds, and I assume the finish is put into the mold first
        (2 K epoxy color, decals), then the glass and the epoxy. The surface
        is incredibly smooth. I try to imagine the hours of polishing...

	The speed records he set with the ARIANE 5 are ~255 km/h for 200 m
	and ~244 km/h for a square pattern. That's about 156 mph!

        These planes are not built "crash proof". The wing is attached with
        two steel bolts!

        He had with him an elevator of an ARIANE recently crashed (experts 
        still have to fight bad RX batteries!). This showed the excellent 
        building technique and strength. It was equipped with some solar cells 
        to help the receiver battery (no BEC in this range of power!). They
        were pressed into the mold during construction. This way they bend a 
        bit, but they have exactly the required profile and no additional 
        cover that might lower their output.

        How did the crash occur? Well, we were told to be careful with high
        speed ships and the required high preformance servos. After a success-
        full flight, the pilot deflected the flaps and ailerons during the
        landing approach (crow landing). This means that 4 servos pulled 
        against the hinge (glass surface) and the airflow. With the bad
        battery, the voltage dropped below 3 V, and that's too low. GRAUPNER/JR
        systems should work down to 3 V (failure of one cell is not fatal),
        but in this cae, the load was too high. If the solar cells had anything
        to do with this, I'm not sure.


        2.) The second plane he broght along was the SOLARIANE. As far as I 
	know, it's the best pure solar plane today. He flew several records
	with this one, too. It is powered only by the solar cells in the wing,
	for the receiver there are cells in the elevator. There is no buffer
	battery for the motor, but I think a small one for the flight pack.
	The plane is controlled with rudder, elevator, motor controller and
	an (I think automatically) adjustable propeller. This automatic control
	assures the best efficiency of the solar generator/motor/prop system
	under all conditions.

	The wing is plyhedral and comes in three parts with solar cells only
	in the straight part. The cells make the upper surface of the special
	profile (upper side as straight as possible) as described on the 
	elevator above. It's again incredibly light, even with all the cells.

	The fuse is simply (?) a stick wound of carbon fibres. It has the 
	diameter of the biggest component it has to host, the electric motor.
	Electronics seem to be custom made or at least modified to fit. Note
	that the antenna was hanging out of the fuse because a carbon fiber
	fuse acts as a good HF shield.


	This is what came to mind a couple of weeks after the event. If you're
	interested, feel free to ask further questions. Right now, I'm sorry
	for not being able to include exact technical data for the SOLARIANE.
	Maybe I can dig something up if you're interested.

	Regards,
                 Hartmut
386.3German F3E report interestingELMAGO::TTOMBAUGHHigh Plains DrifterMon Jan 08 1990 16:5438
    re: .305
    
    Hartmut,
    
    Thanks very much for the F3E info. At least a few of us are interested
    in hearing of the latest developements.
    I have a few questions:
    
    1. What sort of material and finishing methods allows the upper
    surface of the wing to remain flexible enough to be used as a hinge
    while still retaining (I assume) a smooth, low drag surface?
    
    2. The 3 position motor control is the only speed control available?
       No continuously variable current control?
    
    3. I assume the variable pitch prop is Dr. Weissgerbers' custom
    design and not a commercially available unit. Correct?
    
    4. What is the flying weight (without motor batteries) and the
    approximate wing loading. Metric units ok.
    
    Some observations:
    
    The Graupner motor is only $10 cheaper than here in the States.
    Interesting. The Plettenberg unit is unknown here.
    
    Solariane appeared in a recent American model publication. You confirm
    my suspiscions of the carbon fuselage.
    
    
    My attempt at a solar powered sailplane with battery backup is still
    under consideration. 28 cells, 2A, .5v, would cost $175 here. About
    the same as a medium size 4-stroke engine. 
    
    Keep the reports coming.
    
    Terry
    
386.4Tell us more!!ROCK::MINERElectric = No more glow-glopMon Jan 08 1990 20:1342
    RE: Note 387.305 by KBOMFG::KLINGENBERG 

    Harmut,

    Thank you very much for the reports.  They are very informative.  In
    the world of electric flight, I now understand that the best in
    Germany is far ahead of what's available here in the U.S.!!

    I am very interested on reading more about the methods that were
    used to build the glass and carbon fiber wing.  I'm also interested
    to read more about the type of solar cells used and how much they
    cost.

    Are the planes mentioned available in kit form?  If they are not
    available as a kit, do you have any guesses as to how much they
    would cost if there was a kit?

    I noticed that the ARIANE 5 does not have a rudder.  Is this correct?

    I am also interested in more detail about the ailerons and how they
    are attached to the wing.  You said: "The control surfaces don't
    have conventional hinges, but their upper surface is laminated into
    the wing! No gap, no step. "  Please explain further!!!

    It would also be interesting if you can supply details of the planes
    such as wing area, weight, typical current for the motor, airfoil
    used, and any other similar data.  I assume both planes have a 2m
    wingspan.  Metric units are OK.

    It's great to hear about this leading edge technology.  Keep up the
    good work!!

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/
386.5Its a slick idea...CSC32::M_ANTRYTue Jan 09 1990 16:1219
    regarding the hingless wing,  This is what Rich Spicer and crew used on
    their SYNERGY III that they took to the F3b Champs in France.  A fellow
    flyer has one of the planes.
    
    The wing is laid up in two female molds and when that is cured the top
    and bottom wing panels are joined together, hence you have a hollow
    wing.  They also on the bottom of the wing panel mold in a 1/4 inch
    recess where the joint would go.
    
                    ____
           _________|  |_________________  (exagerated of course)
    
    Then they take the wing and at the front of this recess they cut it.
    then in the recess they take a piece of mylar and attached it in the
    recess.  this mylar piece then extends into the hollow wing portion. 
    So the only thing you have is where the wing was cut and the mylar goes
    into the wing.  The upper surface of the wing will bend (its only thin
    epoxy and glass).
    
386.6Please try againROCK::MINERElectric = No more glow-glopTue Jan 09 1990 16:4641
    Thank you for the explaination, but I'm afraid it's not a good
    enough explaination (at least for me).  Please attempt to draw the
    entire cross section of the wing and try the explaination again.

    Here's what I *think* you said, but I am not sure:

                                              /----Top surface bends here
       __------------________                /
      -                      --------__________
     /                                         ------_____
    |         (main wing)                  _____ (flap)   ----______
     \_____________________________________|   |____________________=-


    Assuming this ugly airfoil would fly, you mold the top and bottom
    halves separately and then join them after they've cured.  A blown
    up detail of the notch in the bottom looks like this:

                                        __________
                   (mylar) ----> ================|
                                        |        |
                 (main wing)            |        |     (flap)
               _________________________|        |_______________


    For a typical chord of (let's say) 10 inches, how tall and wide is
    this gap?

    It's too bad we can't draw better pictures then these darned
    character terminals allow...

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/
386.7Some more data...KBOMFG::KLINGENBERGWed Jan 10 1990 06:3525
    Re. 378.308:
    
    This explanation is very good! I'm not really sure how it is done, I
    only know what it looks like when it is done. If you have experience
    with iron-on films, you probably tried to iron on the aileron with the
    film on the top of the profile. Now imagine your cover is thin glass,
    and you have it. Yes, it can make a cracking noise when you deflect it.
    Yes, you need pretty strong servos. Yes, don't forget to make sure
    you're battery can deliver and your receiver and cables can handle the
    required current. But I assume with this kind of ship, the aerodynamic
    load on the servos is A LOT bigger than the spring force of the
    aileron.
    
    Sorry, I don't have time to enter more today. And I'll be off from this
    afternoon until probably Friday (business trip). I will get back with
    technical data of the SOLARIANE. Al Ryder, can you jump in before me?
    Not sure yet if I will find anything about ARIANEs. What I can
    remember:
    			Profile:	Giersberger don't know which (RG?)
             		Accu:		27 cells 900 SCR (weighs ~1.1 kg)
    			Span:		~2 m
    			Total weight:	estimated 2.5 kg
    
    Regards,
             Hartmut
386.8The recess is not that thickCSC32::M_ANTRYWed Jan 10 1990 13:596
    re: the picture.  Everything is correct but,  The recess where the
    mylar goes is only as thick as the mylar, so when you put the mylar in
    the recess it brings the surface back up to flush.  
    
    Does that clear everthing up?
    
386.9On SOLARIANE and ARIANE 5 (F3E)KBOMFG::KLINGENBERGMon Jan 15 1990 11:12119
Sorry, guys, didn't find the time for a reply until now. And the technical
data are still missing. I don't have them myself, and a friend who brought 
them along today forgot to give them to me and is now off for a business
trip. Anyway, I will try to answer at least some more of your questions:


	Terry:
    
>    2. The 3 position motor control is the only speed control available?
>       No continuously variable current control?
	
 	Correct. He indeed uses the most famous and expensive (proportional) 
	controller available in Europe and probably in the world. A swiss
	made controller from Sommerauer. But he only uses it to "soft switch"
	his high power motor. He says that during a contest (that's what the
	planes are made for), he needs both hands on the sticks. And the back/
	forth stick channels are used for elevator and (crow) brake. It is
	easy to switch with a finger, but too complicated (for contest
	situations, again) to use another prop channel. He only needs full
	power anyway (speed and climb), the half-power position is only
	to take care of motor and prop. ARIANE ONLY!!!

>    3. I assume the variable pitch prop is Dr. Weissgerbers' custom
>       design and not a commercially available unit. Correct?
    
	Variable pitch prop is SOLARIANE ONLY!!!
	The prop is designed by Mr Schoeberl, a friend of Weissgerber. It
	is not commercially available, but a very important component for
	the success of SOLARIANE. I'm not really sure, but I seem to remember
	that I read an article about automatic control for SOLARIANEs motor
	and propeller to fly with optimum efficiency under all conditions.
	If the information I hope to get on Wednesday says anything about this
	issue, I'll let you know.

>    4. What is the flying weight (without motor batteries) and the
>       approximate wing loading. Metric units ok.
 
	Not sure if I can find more details on this one.

    
>    The Graupner motor is only $10 cheaper than here in the States.
>    Interesting. The Plettenberg unit is unknown here.

	The January issue of MODELL says that Weissgerber set speed records
	even with the ULTRA 2000. But he outperformed them some weeks later
	with the PLETTENBERG. There are several brands of high quality motors
	available in Germany: Plettenberg (brand name of motors is 
	Hektoplett), Geist, Keller (now carried by Robbe, probably as 
	unavailable in the US as they are here) and Graupners Ultra series.

	Plettenberg, Geist and formerly Keller are small companies that mostly
	sell their products directly to their customers. They don't do much
	advertising, produce in small volume and are very flexible to meet
	the personal needs of competition participants. 

>    I am very interested on reading more about the methods that were
>    used to build the glass and carbon fiber wing.

	Dan, I fear I must disappoint you as I can't explain the method to
	build wings like the ones I saw there. I don't have the equipment 
	and am not very experienced with glass myself. I just tried to 
	describe the finished planes I saw and remembered what I learned
	11 years ago when I was at Akaflieg Braunschweig working on full
	scale gliders (only for a few months). Not enough for projects like
	these. If you have access to someone who is capable of German, I 
	might try to dig up a book for you. Let me know.

>   I'm also interested to read more about the type of solar cells used and 
>   how much they cost.

	Sorry, the only thing I know is that they are from TELEFUNKEN 
	(subsidiary of german AEG). I'm not sure if the data I hope to
	get says something about it. Weissgerber buys them from a very
	small company owned by (you guessed it) his wife. Regarding cost: 
	The only thing I know is they are still way out of my budget...

>    Are the planes mentioned available in kit form?  If they are not
>    available as a kit, do you have any guesses as to how much they
>    would cost if there was a kit?

	No, there is no kit available. If it was, the ARIANE would probably
	cost at least $400, the SOLARIANE probably at least twice as much.
	The SOLARIANE was originally built in professional moulds (to achieve
	the required quality) and it is said that it would be easily 
	reproducable if a small company would want to build them commercially. 
	I assume noone took the risk yet because I never heard about it any 
	more. Probably no way to earn money with the price the kit would cost.

>    I noticed that the ARIANE 5 does not have a rudder.  Is this correct?

	Yes. There is a version with rudder, but the ones he brought along
	and the one he set the records with don't have a rudder.

>    I am also interested in more detail about the ailerons and how they
>    are attached to the wing.  You said: "The control surfaces don't
>    have conventional hinges, but their upper surface is laminated into
>    the wing! No gap, no step. "  Please explain further!!!

	I think this is clearer now from the recent discussion than I could
	have ever explained it.

>    It would also be interesting if you can supply details of the planes
>    such as wing area, weight, typical current for the motor, airfoil
>    used, and any other similar data.  

	Motor current is in the range of 30 to 50 amps (can exceed 60 under
	special circumstances). I'll let you know more precise data when I 
	find them. This is, of course, only for ARIANE!
 
>    I assume both planes have a 2m wingspan.  Metric units are OK.

	No, 2m is only for the ARIANE 5. The SOLARIANE is designed for solar
	power only. This means it flies very slowly, has a low wing loading
	etc. Typical motor current is probably less than 5 amps, maybe less 
	than one. More accurate data on SOLARIANE hopefully on Wednesday.

Regards,
           Hartmut
386.10Access to Hectoplett motors and Italian props...KBOMFG::KLINGENBERGWed Dec 19 1990 12:3569
         Ed,                                                                    
                                                                                
         thanks for the progress update. Very interesting! I enjoyed            
         reading it (although - or because - your projects are beyond my        
         capabilities).                                                         
                                                                                
         > Or Hectoplett 335 (mumble...) motors with ? cells. These are         
         > the most expensive motors, hence the interest and use by the         
         > Swiss (who hold the int'l record..). Hartmut, you have any           
         > access to these...? ;-)                                              
                                                                                
         Haven't tried yet. My budget somehow reduces the interest in the       
         most expensive motors. But Plettenberg (manufacturer of                
         Hectoplett motors) frequently advertises in the mags, so it            
         should be possible to get motor data, prices and finally the           
         motor. Currently, I don't have any of this. If you want to get a       
         price list/catalog/whatever is available, you may want to              
         contact Gerhard Plettenberg directly. His address is:                  
                                                                                
                        Gerhard Plettenberg
                        Werner-Hilpert-Strasse 15
                        D-3500 Kassel            
                        West Germany             
                                                                                
                        Tel.: (from Italy) 0049-561-77 29 55
                                                                                
         You may ask for distributors in Italy, too. If you have any            
         problem (only German info, motors not available in Italy,              
         whatever) let me know. I will be happy to help if I can.               
                                                                                
         BTW, the speed record, as far as I know, was set by Franz              
         Weissgerber (Germany) with his Ariane 5. My entries regarding
         this plane have just been placed as preceeding replies by our
         great moderator (Thanks, Al!). It was powered by a Plettenberg 
         motor and reached 250 km/h. Main contributor was the airfoil 
         DU mumble mumble, look for data in the airfoil file. 
         With a stock ULTRA 2000 motor (GRAUPNER) the         
         same plane still made 244 km/h. Not sure what the Hectoplett's         
         will cost, the ULTRA 2000 is about DM 500,-, but it's readily          
         available even in Kaufbeuren's hobby shops and also through            
         Hobby Lobby in the US. But maybe this data is already old 
         (speed record of 250 km/h, set by Franz Weissgerber).

         Regarding number of cells in F3E - as far as I know, the
         'big class' (don't know how it is really called) has a 
         weight limitation for the batteries: 1.1 kg max. This leads
         to the 27 cells of 900 mAh, and people seem to prefer higher
         voltage (more, but smaller cells) than would be achievable with
         1200 mAh cells.
                                                                                
         Now I've got a question regarding carbon fibre props:                  
                                                                                
         > Home made. Epoxy/C-F high-speed profile. Folding. Use several        
         > different sizes. Presently using a 32 x 15 (12.6 x 6) tapered        
         > for the 12 cell setup. This is another art and the fellow            
         > making them at the club also make them for the Italian               
         > champions in electrics. Uses female molds and carbon roving.         
         > We trade...                                                          
                                                                                
         Is there any chance to extend the trade to here? 12.6 x 6 might        
         be exactly the dimension I'm looking for (I'll make sure by            
         looking up Keller's recommendation for my setup MPX FIESTA SF,         
         Ke 40/10, 12 cells 1200 SCR). I currently fly it with the              
         GRAUPNER 11 x 7 folding prop, but I assume a larger diameter and       
         carbon fibre might help performance. Please let me know if you         
         see a chance to get a pair of blades for me.                           
                                                                                
         Best regards,                                                          
                       Hartmut                                                  
386.11Plettenberg and Ultra motorsKBOMFG::KLINGENBERGWed Jan 16 1991 08:2417
    Ed,
    
    I just received a new mag yesterday (Aufwind, a special magazine for
    gliders, electrics and experimentals). They had some additional
    reporting on the F3E world championship, and diagrams of the two most
    interesting motors: the GRAUPNER ULTRA 2000 and the PLETTENBERG
    HP355/40 6 (this means: 355: armature-diameter, 40 armature-length,
    6: number of windings). The power of these motors is _VERY_ similar, 
    and rumors have it that the ULTRA motors are made by Plettenberg, too.
    Main difference is that they are machine-wound while the HP are
    hand-wound. The ULTRA 2000 is readily available at a hobby shop here in
    Kaufbeuren at DM 379,- (I thing the retail price is DM 498,-).
    
    Just let me know when you need me...
    
    Best regards,
                  Hartmut
386.12What F3E is all aboutKBOMFG::KLINGENBERGWed Jan 16 1991 08:3824
    Here are some numbers to get an idea what F3E is all about. If you want
    to be among the first ten in Germany, you must have at least 22 times
    the distance of 150 meters. Only Franz Weissgerber regularly achieves
    24 and sometimes 25 or 26 times...
    
    The flight has to be completed in 180 seconds. Reduce it by 45-50
    seconds of climb, 20 seconds for the distant turnarounds and 15 seconds
    for the close turnaround, there are only 90-95 seconds for the real
    distance. All in all they ruin a height of about 1000 m (with three
    climbups) in this time. This means a flying speed of 53 m/s or 190
    km/h or 120 mph. This means you have to turn around every 3 seconds.
    With every turn the plane sees an acceleration of 20-25 g, this
    corresponds to a load of 65 kg (143 lb) on the wing that weighs 400 g
    (14 oz). This is really high-tech and $$$.
    
    Equipment for the first twenty in Germany is: GRAUPNER/JR mc-18 radio
    system, motors from Plettenberg or GRAUPNER ULTRA, controllers from
    Sommerauer or Schulze, batteries Sanyo cut-off. There just seems to be
    virtually no other material in this class...
    
    I think I'll better stay with the simple stuff and keep having fun.
    
    Best regards,
                  Hartmut
386.13'92 F3E WORLD CHAMPIONSHIPSUNYEM::BLUMJMon Oct 12 1992 14:1441
                     FOURTH F3E WORLD CHAMPIONSHIPS
                     ******************************
    
    PAPENDAL,ARNHEM,HOLLAND 16-23 AUGUST, 1992.
    
    THE REPORT BELOW CAME FROM THE BEFA NEWSLETTER.
    
    
    JERRY BRIDGEMAN OF THE USA FLEW AN INCREDIBLE 27 LEGS IN DISTANCE AND A
    NEAR PERFECT DURATION TASK TO PUT HIM AT THE TOP IN ROUND ONE, A
    POSITION FROM WHICH HE SELDOM SLIPPED.  SWISS URS LEODOLTER WAS THE ONE
    LEG WORTH OF POINTS BEHIND AND WORLD CHAMPION RUDI FREUDENTHALER WAS IN
    THIRD POSITION.  FOURTH WAS THE YOUNGEST PILOT(21 YRS) JASON PERRIN
    (USA) AND ONLY POINTS SEPARATED THESE THREE.  IN FACT, FROM ROUND TWO
    ONWARDS THE TRIO PERRIN,BRIDGEMAN,FREUDENTHALER WERE AHEAD OF THE REST
    AND THE ONLY ONES TO WIN ROUNDS.  SCORING IS AGGREGATING THE BEST SIX
    OF SEVEN ROUNDS AND AT THE END OF ROUND SIX BRIDGEMAN WAS 26 POINTS
    AHEAD OF FREUDENTHALER WHO WAS JUST 5 AHEAD OF PERRIN.  THIS WAS THE
    BIGGEST LEAD ALL WEEK, BUT ANY SLIP IN THIS LAST ROUND COULD CHANGE THE
    ORDER, FOR EACH'S DISCARD ROUND PUT MOST OTHER COMPETITORS SCORES TO
    SHAME.  ONLY THESE THREE PILOTS SCORED 27 LEGS IN DISTANCE, AND NOT
    EVERYTIME.  URS MIGHT HAVE, BUT CROSSED THE SAFETY LINE ON THE 26TH!
    IN THE LAST ROUND SUPERLATIVES FAIL TO DESCRIBE RUDI'S PERFECTLY
    REGULAR 27 LEG FLIGHT, CAREFULLY OBSERVED BY HUSHED SPECTATORS AND
    OTHER COMPETITORS.  JERRY FLEW SOON AFTER, AND CONCENTRATING, OR
    NERVOUS, OR GIVEN A BAD CALL, HE CUT TWO GATES, FLYING 25 LEGS. 
    CUTTING JUST ONE WOULD HAVE GIVEN HIM THE WORLD CHAMPIONSHIP, FOR HE
    WAS ONLY ONE SECOND OUT IN DURATION TIME, WITH 4 SECONDS OF MOTOR TIME
    AGAINST RUDI'S IDENTICAL DURATION SCORE OF 5 SECONDS MOTOR BUT PERFECT
    TIMING.  RUDI FREUDENTHALER OF AUSTRIA IS WORLD CHAMPION AGAIN!  THERE
    STILL HAS BEEN NO OTHER.  THE FINAL STANDINGS ARE AS FOLLOWS:
    
    1-RUDI FREUDENTAHLER(AUSTRIA)
    2-JERRY BRIDGEMAN(USA)
    3-JASON PERRIN(USA)
    4-URS LEODOLTER(SWITZERLAND)
    5-FRANZ WEISSGERBER(GERMANY)
    6-MICHAEL GERINGER(AUSTRIA)
    7-STEVE NEU(USA)
    
    THE USA WON THE TEAM GOLD MEDAL.
386.14............silenceKBOMFG::KNOERLEMon Oct 12 1992 15:0810
    
    What an exciting report, almost like a psycho thriller. Heads up to the
    team US - what a success. Your boys moving well along - World Champ
    F3A, team world champ F3B, team world champ F3E (if I recall correct).
    Where are our boys, eh ?  At least Freudenthaler is speaking a German
    language - well, kind of :-)
    
    
    Bernd
    
386.15Waco 550-10 updateUNYEM::BLUMJTue Oct 13 1992 16:2023
    In fairness to Frank Weston, I must retract some of my earlier
    statements about my WACO 550-10 kit.  Getting 10 cells in this 
    bird is actually not that difficult.  I learned some "new"
    techniques for battery configurations by observing the F3E style
    ships at KRC. I now have easily placed 10 cells in the Waco with
    Rx battery and discrete on/off switch.  I still do not like the
    V-tail control arrangement and will be substituting a T-tail
    with elevator only control via a fin mounted servo.  
    
    The flying weight with Ultra 900 motor and 10 1000 mah Sanyos
    should be around 50 oz.  This motor in my 64 oz. Arcus raised
    some Eyebrows at power funflys, so it should be a good climber
    at 14 oz. less weight!  Hopefully I'll get the 4-5 climbouts to
    around 1000 ft., that I am looking for.
    
    I will report when it flys.
    
    
                                                 Regards,
    
                                                 Jim  
    
    
386.16How??? Can you explain a little detailed?LEDS::KLINGENBERGWed Oct 14 1992 14:079
    Jim,
    
    NOW you got me curious! What magic do these guys use that we both
    didn't think of? Your message seems to indicate (I know it can't be
    true:-) that there is plenty of room in the fuse now. But I guess not
    plenty for the Ke70/4 yet, or does this even seem to be possible?
    
    Best regards,
                   Hartmut
386.17Here's howUNYEM::BLUMJWed Oct 14 1992 16:5814
    Hartmut,
     
           The biggest difference is I substituted a Graupner Power
    Switch 40 and 100 mah Rx battery for the Power Switch 20 on/off/bec.
    I also removed the plastic battery templates I was using, which 
    provided just enough more clearance to get the batteries in.  I 
    believe I could get the Keller 70/4 in now.  I will wait to see
    how the finished product flys before making any moves.  If the
    WACO flys well, I will probably experiment with the Keller Motor.
    I am firm on the T-tail substitute.
    
                                                        Regards,
    
                                                        Jim
386.18New productsUNYEM::BLUMJWed Dec 02 1992 14:4221
    With the help of this notes file(Thanks Jean-Claude) I was able
    to get the address of M.A.P., the French builder of the F3E ship,
    the AURA 2.
    
    The specs on this ship look very good and I have read it is of
    all molded construction.
    
    It also appears that Hobby Lobby will be carrying a new Czech
    built motor which did quite well on 24 cells at the recent
    world championships.  This motor is currently available from
    shops in England at very competitive prices.
    
    If the Aura 2 is available, coupled with this new motor, a 
    very competitive commercially available f3e combination may
    be possible at an  affordable price.
    
    
                                                   Regards,
    
                                                   Jim
    
386.19Astro 60 FAI modsUNYEM::BLUMJWed Dec 02 1992 18:3515
    The new Silent Flight Magazine had details of the equipment in use
    at this year's F3E world championship.
    
    Of particular interest to me were the "mods" made by the US team to
    the Astro 60 FAI motors they used.  Since these motors can be had
    for $180, I was hopeful they were basically "stock".
    
    According to the article the motors used had titanium shafts, lightened
    cases and 7 turn(vs. 6 turn) armatures.  The resulting motor weighed
    less than 17 oz!  They also use older Astro molded brushes, as the
    new ones don't handle the 60 amp current as well.
    
                                                         Regards,
    
                                                         Jim
386.20Astro motorsKAY::FISHERThe higher, the fewerThu Dec 03 1992 12:4714
   
>    According to the article the motors used had titanium shafts, lightened
>    cases and 7 turn(vs. 6 turn) armatures.  The resulting motor weighed
>    less than 17 oz!  They also use older Astro molded brushes, as the
>    new ones don't handle the 60 amp current as well.

Huh, at the National Sailplane Symposium Steve Neu(sp) told me his motor
was stock except for the lightening of the case. 

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

386.21I heard the sameUNYEM::BLUMJThu Dec 03 1992 14:3922
    Kay,
    
       Steve Neu also told me that the motor was stock except for
    "lightening" of the case(at this year's KRC).  It is possible that
    Neu's motor is stock and his teamates(Bridgeman and Perrin) had 
    the more modified motors.  This would make sense based on the data
    table listed in the new MA which showed the weight of the ships
    as follows:
    
    Bridgeman - 2200 grams
    Perrin----- 2250 grams
    Neu-------- 2305 grams
    
    Probably the author of the Silent Flight article talked with Bridgeman
    who eventually finished in 2nd place.  The difference in weight between
    Bridgeman's ship and Neu's ship is about 3.5 oz.  A stock Astro motor
    weighs around 20.5 oz. So maybe Bridgeman's motor had the titanium
    shaft and Neu's didn't.
    
                                                       Regards,
    
                                                       Jim
386.22Report of World Championship in Aufwind, tooKBOMFG::KLINGENBERGFri Dec 04 1992 08:1629
    When I came back home, I found the latest issue of Aufwind with
    detailed reports of the world championships. Among others, it showed a
    picture of the ASTRO 60 as used by the US team. I wouldn't have
    recoginzed it as an ASTRO. Of course, if you take a close look, you see
    the 4 brushes, but the housing consists mainly of holes. 
    
    They didn't talk about a Ti shaft, but the material the machined off
    the housing is amazing! It's got lightening holes in the front right
    behind the front plate, between the brush holders and a whole lot
    removed where the magnets are held. It's not round there any more, but
    has a couple of flat surfaces all around, I assume to use as little
    metal in the yoke as possible.
    
    Seems the majority of the leading motors are now - besides the ASTRO
    (which is only used by the US team, I think) - Robbe pro and
    Hektoplett. Most of them are significantly reworked/lightened.
    Freudenthaler has a rule of thumb: 10% less weight = 10% faster climb =
    10% longer flight. Clear as mud, I'd say. I guess I'm far from building
    models light enough to make it worth fiddling with the motor...
    
    They also wrote about the Tchekeslovakian (sp?) motor which will 
    soon be available in Germany, probably for a very competitive price.
    
    I will enter a list of equipment used in the chapionships as I find
    time.
    
    Best regards,
                  Hartmut
            
386.23F3E questions galore!UNYEM::BLUMJFri Dec 04 1992 12:2122
    Welcome back home Hartmut!
    
    I recently wrote for information on how to subscribe to Aufwind.
    The cost was posted at 62 dm, I am really looking forward getting
    it and will ask for occassional help with words not in my German-
    American dictionary.
    
    Did the Aufwind article mention anything about the M.A.P. Aura 2
    which was supposedly used by the Italian team?  The reason I am
    interested, is this model is rumored to be commercially available
    and of all molded construction.  The specifications about it look
    real good.
    
    Also did the article mention any of the large electric gliders 
    which were flown?
    
    Just curious if you took any American RC stuff back for your personal
    use?
    
                                                      Regards,
    
                                                      Jim 
386.24Have to bring the mag inKBOMFG::KLINGENBERGFri Dec 04 1992 14:1151
    Hi Jim,
    
>    I recently wrote for information on how to subscribe to Aufwind.
>    The cost was posted at 62 dm, I am really looking forward getting
>    it and will ask for occassional help with words not in my German-
>    American dictionary.
 
    sure, I'm looking forward to help you out on this.
   
>    Did the Aufwind article mention anything about the M.A.P. Aura 2
>    which was supposedly used by the Italian team?  The reason I am
>    interested, is this model is rumored to be commercially available
>    and of all molded construction.  The specifications about it look
>    real good.
 
    I'm not yet through the technical part of the article, but it stated
    there are not many changes to the last world championships, so it's 
    not too long. Main changes was a trend to smaller models (wingspans)
    with the US team - obviously successfully - having the smallest.   
    I'll double check on the Aura 2, but think I only read about it in this
    notesfile.

>    Also did the article mention any of the large electric gliders 
>    which were flown?
 
    Yes, they said that they try to fly the large ones like F3E and this 
    doesn't look nice. Way too strong motors and everything. They assume
    that they will have some rule changes for the big ones soon.
   
>    Just curious if you took any American RC stuff back for your personal
>    use?
    
    Sure. I spent enough money to put the radio purchase off for at least
    another year - unless I sell something:-(

    I bought 2 Pinnacle Hi-Starts from NSP, one for the Fiesta, one for HLGs.
    I also got a Spirit (to be electrified, but probably with a geared motor),
    a Spirit 100 (cheap entry into 4-servo-wing, maybe also to become electric)
    and a Talon for the slope. So far it was planned. In addition, I found a 
    Bird of Time on sale for $40 and a Genesis HLG flying wing for $20 and 
    couldn't resist. Also some minor stuff (iron-on coatings, latch hooks etc.).

    For non-personal use (friends) I bought a used ENYA 120, a used Tartan Twin,
    another Talon, a Skeeter HLG, another Spirit 100, 1 Gremlin, 1 Gremlin wing
    core set and 2 Chuperosa wing core sets. And some minor stuff as well. No
    Astro motor or radio equipment (this time).

    Best regards,
                   Hartmut
             
386.25MAP AURA INFOMISFIT::BLUMTue Dec 15 1992 14:3229
    I received the information from France on the M.A.P. AURA 2 F3E
    glider.
    
    It is available in 10 and 27 cell configuration for 1700 and 2108
    Francs respectively($426 and $325 @.1913 exchange rate).
    
    It is of all molded construction employing a wing using rohacell
    and carbon fiber spar.
    
    Silent FLight reported this ship was used at this year's World 
    Championship F3E comp. by the Italian team.  At least one member of
    the Italian team achieved 23 laps in the distance event, so it is
    competitive with the best ships in the world.  In FAI dress it 
    weighs 91 oz.
    
    To my knowledge this is the only competitve F3E ship available on the
    commercial market.  At $50 more than the Aeronaut Sunfly and probably
    hundreds less than the Surprise II, it represents good value.
    
    For the first time it is possible to have a world class F3E ship with
    "off the shelf" components.  The price is high for these items, but
    until now you had to "roll your own".
    
    I hope to be able to purchase one of these.  I will need to investigate
    shipping cost and duties.
    
                                                       Regards,
    
                                                       Jim
386.26More Aura 2 infoMISFIT::BLUMThu Jan 07 1993 12:4825
    I received another letter from M.A.P. in France with additional
    information about shipping the AURA 2 F3E gliders to the USA.
    
    It is estimated that the cost to ship 1-4 sailplanes is about
    800 FF = $160(ouch!) + any applicable USA duties.
    
    I will call Ed Slegers and ask him his experiences with buying
    the  4 Freudenthaler gliders from Austria.
    
    If USA duties are minimal or non-existent, I may attempt to
    find a couple other buyers and go for it.
    
    The letter included 3 35mm color photos, including a 3"x6"
    closeup of the Aura 2.  If the gliders M.A.P. is shipping
    are the same as the one's in these photos, the quality is
    fantastic!
    
    Damn the shipping and duties, these are beautiful gliders!!!!!
    
    
                                               Regards,
    
                                               Jim 
    
    
386.27Import updateMISFIT::BLUMTue Jan 12 1993 13:1927
    I spoke with Ed Slegers(RCSD columnist) about the fees associated
    with importing model airplanes(specifically the M.A.P. AURA 2).
    
    He already has 4 Auras on order!
    
    Ed says the duty fro model airplanes is 6.8% of declared value, and
    customs fees are about $150.
    
    He will sell an Aura for $850, which is about $50 more than you could
    import one yourself.  I think it is worth $50 to let him take the
    risk.
    
    Ed also carries the Freudenthaler Surprise III for $850.
    
    So while these ships are pricey, world class performance is available 
    for this with large wallets.
    
    The ships themselves are about $450-$500, it's the shipping and import
    duties which put them out of sight.
    
    Guess I'll continue trying to perfect my composite building skills!
    
    
                                                            Regards,
    
                                                            Jim
                                                   
386.28Modellhaus offeringsMISFIT::BLUMFri Jan 15 1993 11:5524
    I finally received a reply from Modellhaus in England.
    
    A list of the products which can be delivered now or soon was
    included.
    
    Of interest to me is the Trabi F3E fuselage, made of Kevlar,
    27 cell capable, weight = 130 grams.  Price is 33 lbs.
    
    All moulded RG15 wings will be available in the spring.
    
    If there are no shipping problems, I will be ordering a Trabi
    fuselage ASAP.
    
    The MEGA F3E motor is available for 124.7 lbs.
    
    The owner of Modellhaus is Dave Jones who is an accomplished
    sailplane pilot.
    
    I'll report on my ordering experience.
    
    
                                                     Regards,
    
                                                     Jim
386.29TRABI fuz arrives!MISFIT::BLUMWed Feb 17 1993 11:5619
    I received the TRABI fuselage from Modellhaus last night.  I am
    VERY pleased with it.  It is kevlar, with white gelcoat.
    Little additional finishing will be necessary, it weighs 130 grams
    and can accomodate up to 27 cells!  It was manufactured by
    Pekris in Czechoslovakia.  It cost $65 delivered.
    
    I have just ordered a MEGA R7 motor from Modellhaus to be run on
    24 cells with the Trabi fuse and a 2 meter RG15 wing.  This will be
    my first F3E ship.
    
    Modellhaus is stocking soft competition brushes for the Mega motors
    and carbon fiber props in a wide range.  F3E equipment is slowly
    becoming available at better prices.  The TRABI fuselage is a prime
    example.
    
    
                                                     Regards,
    
                                                     Jim
386.30Mega motor arrives!MISFIT::BLUMTue Mar 02 1993 14:2210
    Last night the Mega R7 motor (Czech built) arrived from Modellhaus
    in England.  It was waiting along with 3 different sets of carbon
    fiber props in my mailbox.  I sent an international money order
    which I got from my local bank for $15.  There were no problems
    I encountered.  So I now have a great motor, fuselage and prop
    selection.  I need to build my own wing and stab.  
    
                                                     Regards,
    
                                                     Jim
386.31F3E UpdateMISFIT::BLUMThu Jul 01 1993 21:0940
    Just got done talking with Bob Sliff at Hobby Horn(714-893-8311).
    
    I ordered a Steve Neu made speed controller($120).  This is the same
    unit that the USA F3E team used.  It is small and robust.  I highly
    recommend it, as it is $100 cheaper than the Sommerauer unit and
    smaller and lighter than the Astro 205.
    
    Other F3E news, Jason Perrin will not be vying for a spot on this
    year's F3E team.  Bob Sliff(Hobby Horn owner and F3E team manager)
    said Jason has graduated from college this year and did not want
    to devote the time necessary to build, practice, and prepare for
    the world championships.  This is a big loss to the team, as Jason
    has finished 3rd and 2nd respectively in the last two world champion-
    ships.  He was truly a world class competitor.
    
    F3E remains in a very sad state in this country.  Bob said only 6
    people have signed up for the USA team qualifier in San Diego.
    He mentioned that there was a group of seven in Texas that was
    trying to get it going down there, but had fallen off to only
    1 now.
    
    The USA team is completely redesigning the Cad Cat pylon racer
    and making changes to the F3E design.  Steve Neu has a Robbe Pro
    motor and is impressed with the performance.  They are also
    considering using Hectoplatt motors as the efficiency if better
    than the Astro motors(owing to the brush design).
    
    Jerry Bridgeman is the aerodynamics guy behind the USA F3E effort,
    and Steve Neu can build both composite planes and does electronics.
    
    They represent this country very well, I only wish we could get
    more involvement.  Thirteen people in a country of 250 million
    is not too impressive.  Wishful thinking!
    
    
                                                   Regards,
    
                                                   Jim
    
    
386.32exMISFIT::BLUMFri Jul 02 1993 13:5830
    As an addendum to the previous note, I will include a few more
    excerpts from my conversation with Bob Sliff.  Bob is an excellent
    source of information because as team manager he has been to several
    World Championships and has seen the equipment/techniques used by the
    best in the World.
    
    -Hectoplatts remain the hands down favorite motor for F3E competition.
    
    -Brush cooling provision is really needed in the F3E motors.
    
    -A competitve F3E fuselage  weighs about 3.5 oz.
    
    -The wings of the best F3E ships weigh about 12 oz. and are unbreakable
     due to flight loads.  Bob witnessed several ships break up in the air
     during practice, including the MAP AURA 2.  I persisted that probably
     a heavy thumb on pullout was responsible, but he remained adamant that
     the best ships simply cannot be broken in flight.  The team apparently
     has tried to break the ships and has not been successful!
    
    -The construction of a world class F3E ship is very labor intensive,
     requiring 4 different vacuum bagging operations.  Even the fuselages
     are utilizing Rohacell sandwich construction.
    
    -No real good props are available commercially.  Custom made props are
     the norm and are usually sanded to shape, based on empirical testing.
    
    -The new Robbe Pro motors appear to be quite competitive.
    
    -Hobby Horn is selling a kevlar reinforced glass F3E fuselage for $80. 
     
386.33Surprise II readyMISFIT::BLUMMon Aug 30 1993 20:5120
    The RFM Surprise II is complete and ready for its maiden flight.
    
    I am nervous because I have not flown since the 2nd week in July
    and the cost of this ship makes a crash seem unthinkable.  This is
    my only flyable electric right now and I want to take it to KRC
    Sept. 18th.  I feel pressure!  
    
    Initially the Surprise II will be flown on 10 1000mah cells using
    a Keller 70/4 and MH 12.5x6.5 prop.  All up weight in this confi-
    guration is 62 oz.  
    
    Flight results will be posted.
    
    
                                                      Regards,
    
                                                      Jim
                                        
    
     
386.34We await your resultsGAUSS::REITHJim 3D::Reith MLO1-2/c37 223-2021Tue Aug 31 1993 12:065
Best of luck, Jim. I'm sure it'll fly right out of the box with 
all the effort you've put in. Just take it easy initially and 
slowly widen the envelope. Looks like it might be a bit breezy 
the next few days though. But then maybe that's what you need to 
get a slower ground speed on landing.
386.35It flew!UNYEM::BLUMJTue Sep 07 1993 11:5816
    The first flights of the Surprise II happened this weekend.  All in all
    it went very well.  The climb on 10 cells with a Keller 70/4 spinning
    a 12.5 x 6.5 MH prop was very good.  It flys right out of my hand
    and climbs immediately.  This prop is certainly more efficient than
    the 10 x 6 used in the past.
    
    I am still sorting the trims out and trying to get the
    spoilerons/elevator coupling dialed in.
    
    The aerobatic and high speed capabilities will be tested after the
    KRC meet(Sept. 18-19).
    
    
                                                         Regards,
    
                                                         Jim
386.36GAUSS::REITHJim 3D::Reith MLO1-2/c37 223-2021Tue Sep 07 1993 12:031
Congrats Jim. Does the performance meet your expectations?
386.37I like it!UNYEM::BLUMJTue Sep 07 1993 13:3921
    re: -1
    
    Jim,
    
       I am satisfied so far, particularly with the climb on 10 cells
    owing to an AUW of 62 oz.  It is also easy to change 10 cell packs.
    I think balancing with 20 cells will be tricky, however.
    
    I only got 4 flights due to run down RX and TX packs and rain.
    
    With over $1000 in hardware in this ship, I was really babying it.
    Also, I want to be able to take it to KRC in 2 weeks without damage.
    
    Overall I am very impressed with the ship.
    
    
    
                                                              Regards,
    
    
                                                              Jim
386.38GAUSS::REITHJim 3D::Reith MLO1-2/c37 223-2021Tue Sep 07 1993 13:529
Yeah, things get expensive when you get away from the 7cell ships. How 
did you decide on the prop/cell combination? Where'd you get the 1000mah 
cells? I'm still figuring on using the Astro 25 cobalt with the Jet 
fuselage on 16 cells but haven't decided on an airfoil or prop yet. I 
have an SR Batteries gift certificate so I'll probablyu order the 
batteries from them. I'd like to go with the 1000mah cells as well but 
none of the places at the shows I've been to have had them in stock.

What airfoil is the Surprise using?
386.39UNYEM::BLUMJTue Sep 07 1993 17:4631
    RE; -1
    
    Jim,
    
       The Keller 70/4 is optimized for use with 10 cells.  I was using
    it with 14 cells in my Calibra with a 10-6 Aeronaut prop.  The 70/4
    is designed to spin a large prop on 10 cells and is capable of 
    handling 80 amps for 30 seconds.  Based on information published
    in a British magazine by one of their F3E team members, I decided
    to use the 12.5-6.5 as a starting point.  It appears to be just
    about right and is turning 8000+ RPM.  Run time is around 1 minute
    with the 1000mah cells.
    
    The Surprise uses the RG15 airfoil(who isn't these days?)
    
    I get my batteries from TNR(see RCSD), both the 1000 and the 1400 mah
    are $3.50 each(lowest price I have seen). If you buy them don't get
    solder tabs which impede soldering the pack.
    
    Actually I am kind of in shock right now that I actually bought the 
    plane.  I am not comfortable flying(or even building for that matter)
    a model in this price range.  Must have been temporary insanity.  Sure
    hope I get a lot of good flights!
    
    
                                                           Regards,
    
                                                           Jim