I have a Kadet ARF that I am assembling and I noticed before assembly that the small elevator control surface had a slight bow in it length wise. Thinking that this would not be much of a problem since it was on the flat side and the joint along the long edge was completely straight I assembled it with CA, now it has a slight snap motion when going up and down, this causes a up/down motion of the main elevator surface tips when the control surface is moved up and down. The joint is still tight but the motion makes me wonder if the servo will have any problems with this snapping motion when moving through center. The surface has a slight up elavator look to it. My question is can I straighten out the flat side bow without having to remove the control surface an replacing it ? I have no problem removing the surface but I would like that to be the last resort since I would have to install different hinges. Can some one help me.



Pic shows resting state.

Pic shows flexed down.

Pic shows resting state.

Hmm, can't really think of any other way to flatten that bow out without removing. But first of all, does it snap pretty hard passing thru center and more importantly, can you leave it at neutral, or does it snap to slightly up or down elevator. See where I'm going with this? If you can’t leave it at neutral (level flight) and it keeps wanting to snap up or down, you’re going to have one heck of a flying experience….can we say roller coaster?

Secondly, if I remember correctly, that plane came with CA hinges. Personally, I’d cut the elevator out; strip the covering off, toss in a zip lock and soak in some water. Remove from bag, place between two flat boards, clamp or weigh down, and let thoroughly dry. This ‘should’ take the bow out, but takes to much time. OR spend a few bucks and get a new elevator from LHS.

As for the hinges, trim the old ones and sand flush. Now create new hinge slots, as close to the originals as possible and reattached H-Stab.

Try this...

Block it and weight it so that it is bending in the opposite direction. You will have to bend the stab also to accomplish this. Using a heat gun (not a hair dryer) apply heat to the elevator, but avoid heating the stab too much. Let it cool completely, then remove and weights or hold-downs and see if it has straightened out any.

You may have to try it several times to get it completely out.