Setting up the ailerons to give the specified deflections is not always as easy
as it should be. I have known occasions where it was impossible.
It might be thought that the position of the drive pin is the main critical
criterion. In fact it is it's relationship with the hinge pin that is crucial
because this determines the radius of the drive pin's locus, and therefore the
angle the aileron deflects for a given movement of the push rod. The plans
unfortunately don't specify this dimension, WHICH NEEDS TO BE ACCURATE TO 1/64"
or less, relying instead on all the other dimensions being accurate. IMHO you
will save yourself hours of frustration if when you finally fit the hinges to
your ailerons you make up a simple jig, which need only be two holes in a small
aluminium plate, a 1/4" hole for the pin and a 3/32" one for the hinge pin. I
guess Andy's CAD might be able to tell us the distance between the hole centres.
A pencil line on the plate should be added to align the bottom surface of the
aileron.
If you have not yet fitted the hinges you might like to do it this way.
Mount the hinges on your straight edge as described in the plans. Leave the
inboard hinge pin protruding 1/8" or so (unbent). Now flox the hinges to the
aileron, again as per plans but drop your jig over the pin and the AN4 bolt. Use
skin pins (rather than Clecos) to hold the hinges in place but don't overtighten
so as to avoid distorting the flanges. Allow to cure thoroughly before
rivetting. This way you will end up with the two ailerons working together
instead of fighting.
If you've already finished your ailerons it would be well worth making the jig
to fit one and using it to check the other. If they don't match decide which one
to alter and fix it. Easiest probably to move the hinge, but bear in mind you
don't want to cause misalignment of the other hinge.
Believe me, 1/16" discrepancy is too much {{8-<)
Graham
It's quite likely that the main reason for difficulty is a difference in the
position of the hinge and drive pin is not identical in bothtwo ailerons
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