| 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 |
Looks like we need a discussion on HOLLOW AILERONS and the
understanding of their strengths and weeknesses.
Back to Kay's comments of 962.2;
Kay, when you talk about cap strips on the rib tips (poetic aren't I)
do you support the strips by maybe doubling the rib tips. This plane
has a 50" wing which is not very big and the ribs are very thin. It
does show some capping, but its very hard to tell where they want it
done. On my Chipmunk I capped all ribs. This plan says to cap only
a few which would screw up the sheeting of the wing.
Anyways, the question is should I (my brother) double up the aileron
tips for strenth and then cap and sheet them?
One other question. I believe there is a piece of ply that must be
mounted somewhere in side the aileron for the connection of the
aileron linkage horn. Should this be beefed up at all?
Ken
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 964.1 | My advice. Good? | CURIE::ANKER | Anker Berg-Sonne | Fri Apr 14 1989 15:04 | 39 |
Re:< Note 964.0 by BRNIN::SOUTIERE >
Ken,
I have built two Aeromasters and one EAA bipe with hollow
ailerons and have gained a bit of experience. On both of these
plans the airfoil is so thick and the ailerons so broad that a
solid aileron would be hard to build.
I have found that the hardest part is to cut the ailerons
out. As you probably know the wing is built first, sheeted and
THEN the ailerons are cut out and finished.
On both planes the ailerions are fully sheeted and plenty
strong. The small piece of ply is there to ensure the aileron
horn screws have something to bite into and don't contribute
significantly to the strength, so glue them directly to the
sheeting.
Now to the really important stuff. It is absolutely
necessary with this type of aileron to ensure that air cannot
flow through the crack between the aileron and the wing. I do
this by covering and hinging and then attaching a strip of
covering across the gap from below. Do this with the aileron
deflected in the full up position, What you will discover is that
even though the covering will be loose the suction will ensure
that it never hangs out of the slot. It is totally invisible and
extremely effective.
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Hang in there! o_|_
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Anker \_|_/
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| 964.2 | Two Servos | LEDS::WATT | Sun Apr 16 1989 23:47 | 18 | |
I'll echo Anker's advice on hollow ailerons. They end up stronger and
straighter than strip ailerons out of solid stock. Cutting them out of
the wing is not easy - you need a nice sharp blade and a straight edge
and careful measurement to get it right. Cutting through the ribs is
the hard part since this is cross grain. Most strip ailerons are too
flexible and they often come warped. Built up ones are lighter as well
as stronger.
The other difficulty with built up ailerons is actuating them. My
Aeromaster used belcranks mounted in the wing and a single servo in the
center. I had trouble with this system developing slop due to too many
pivot points and wear in the belcrank pivot. I finally scrapped the
belcrank system and put two mini servos in the wing. Now I have a very
solid system with no aileron slop. I also have two servos so that at
least one aileron will work if one of the servos fails. I would
strongly recommend this approach wherever possible.
Charlie
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| 964.3 | Try Foam Ailerons | GIDDAY::CHADD | Mon Apr 17 1989 22:07 | 12 | |
Why not use foam wings. I build my wings and then cut out the ailerons attaching a piece of 3/16" to the exposed foam on the wing, trim 3/8" of the aileron and attach 3/16" the exposed area. It is easier/quicker to build a straight wing from foam than buildup and it gives you instant accurate Hollow Ailerons. Incidentally I use 1/8" wire as torque rods to the ailerons and have no flutter problems, just make sure your torque rod goes into a balsa insert in the aileron not foam as if wont last more that a few minutes before it breaks loose. John | |||||
| 964.4 | BRNIN::SOUTIERE | Tue Apr 18 1989 13:30 | 4 | ||
John,
What glue do you use to attach the 3/16" to the exposed foam?
Ken
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| 964.5 | GIDDAY::CHADD | SPR HPS Product Planner | Tue Apr 18 1989 22:53 | 23 | |
Ken, I use West Epoxy however I have just tried some Pic Laminating Epoxy and it is as good if not better. I use epoxy for all my sheeting as it gives you more time to position sheets than contact, it also add's too rigidity of the wing. The process I use is to sand the foam flat using a 3' long sanding block made from a piece aluminium angle then run a line of epoxy along the balsa strip which is laying flat on the bench. I place the aileron on the balsa and tack it in place with some 30 sec CA. I use the 30 sec CA as it does not penetrate a well as the 5 sec and therefore won't/unlightly to reach the foam inside. When making wings don't put the epoxy on the foam as it tends to penetrate the wing and adds weight without any strength. I finish the wing and the aileron with glass cloth and epoxy, the weight of the cloth is 6oz across the center to just past the wing saddle, 3oz on the bottom 1/2 way across the wing; on the top I go to a 1/3 across, and the rest of the wing is epoxy, very very thin sanding it down until the balsa is just not showing through. I use a 1/4 sheet orbital sander with 80 grade paper for sanding wing sheeting and finished wings, it's quicker and less exercise than a sanding block. John | |||||