Composite Aileron Question
 

I have been looking at making some composite ailerons as an alternative to solid balsa ones (which tend to warp, are often heavy and come in limited sizes). I was thinking of using rohacell or depron foam with balsa leading and trailing edges, with the taper sanded into the foam. The skin will be vacuum bagged on using epoxy. I was initially thinking of using carbon fiber because of its stiffness but a quick look at CF prices showed why it is only used where really needed, it's way more expensive than I can justify at this point. So that leaves me with boring old fiberglass. I have glassed my share of things and have no concerns about bagging the ailerons, but I have no feel for how much cloth and what weight I should be using for this application. My gut feel is that a couple layers of 2oz cloth should be lots for 40 and 60 sized models that are being powered by typical sport engines (ie - no Nelson or Jett monsters).

Can anyone confirm my thoughts on the construction methods and how much glass to use? Any other tips/experience/guidance is most welcome.


Thanks,
Mark

A single layer of 2 oz cloth should be just fine. I once replaced the ailerons on a 40% airplane using Spider Foam with a single layer of 3.7 cloth and bagged into place. If you are scratch building from you can cut your cores all the way to the TE and while sheeting put a strip of glass between the foam and sheeting. After the wing has been sanded out simply cut the aileron out. It's a great way to get the aileron to perfectly match the rest of the wing.

Excellent, one layer is even easier to handle and bag. Maybe with an extra piece on both sides of the foam where the control horn hard point is installed, just to make me feel better.


These are for a built up wing or I would be doing just that, it works great for foam wings.


Mark