I have reached the point in the construction of the Piece O' Cake motorglider where I am supposed to cut the hinge slots, prior to gluing the hinge material, and slipping it into the slots. I confess that I have no confidence in my ability to do this right the first time, and rather than taking the time to practice on scrap, I am looking for alternatives. I also have noticed that the hinge material was evidently supposed to somehow hold the rudder up above the post, and keep it from hitting the post when the rudder moves from side to side. However primitive, I would much prefer some sort of purpose-designed bearing surface to perform this elementary function. I would appreciate any ideas whatsoever on this matter.
I've heard of some people making the hinges right out of the covering material and covering right over the hinge line with one piece of, say, MonoKote. Both sides are covered, and it is advisable to try to do the covering with the control surface deflected away from the side being covered, so it will still flex when finished. I had always thought MonoKote wouldn't be strong enough for this, but after using it, I think you could make a fine hinge that way. Even if the plane is already covered, you could still use a generous strip to cover the hinge (MonoKote seams are barely noticeable - formerly another area of concern for me).
If you don't like that idea, and really want to go quick and dirty, use clear packaging tape. I have the rudder taped on my GeeBee that way right now. Apparently, it's stronger than the nylon pinned hinges I put in there that all sheared off! That little bit about deflecting the surface to one side while you fasten the tape applies here too.
About slotting hinges: I cut my first few (in hardwood, at that) with an exacto knife, and yes, mine came out less than perfect. I found the perfect way to cut them after that. If you don't have a drill press, get one! Once you have one, get a dremel cutoff wheel (a little grit disc on a mandrel - looks like a grinder) and chuck it up in the drill press. Then raise the drill press bench to just 1/8", or whatever measurement you need, away from the disk. Then you can take your stock, put it flat on the bench, and slide it up to the cutoff wheel, which will make a perfect, semi-circular slot in the wood. Normally, you'd do this before the part is assembled to the rest of the wing, or plane, as the case may be (much easier that way), but you could probably still pull it off even if the plane is already assembled. The trick is to do the setup right, so you can slot both sides of the hinge without changing the setup, so that they'll mate up perfectly to one another.
As for your bearing surface, that's going to be difficult in any case, no matter the hinge type. A washer would be, I think, the obvious choice, but it should be centered on the hinge line, which would probably involve embedding half of it in the control surface? Do you have a tail-mounted wheel? Or are you placing some unusual up/down strain on the rudder? If not, I probably wouldn't worry about it. I've turned somersaults on my packing-tape rudder hinge, and it's still hanging on tight!
The covering plays a big role in the wings strength on any glider, be it motorized or not. I wouldn't do it, but if you want to cover it with a painted FABRIC you'd be ok. You might want to rethink the covering, because anything other than an iron on is going to add weight. You will need more than an .049 for sure if it's painted. As for the dope, my LHS still carries it, as does the biggest craft store in town. I still insist on fuel proofing the nose with it every now and then. Call me nostalgic.
The smell always makes me think of my tissue covered Goldberg Shoestring with a Fox 29 slinging my boiled TF white nylon prop up front. It was painted royal blue with white trim, the only two colors the four seasons store had in stock. The white prop matched the trim so it looked better than a wood prop ;)
I stocked up a few bottles of each, so I turned out Voodoo's, Jumpin beans, and God knows what else in those colors for two years before I started using anything else (except a Square Soar 72 and Q-Tee in monokote).
Well, I guess now I understand how it is possible to power a plane with a six foot wing span by using only a tiny little .049 engine! Actually, I have decided to use the Norvel .061, because, again, I have found one at a local hobby shop. The Piece O' Cake instructions suggest using EconoKote, so I guess I will just bite the bullet, purchase some additional tools, and apply the EconoKote, if I can find it. Actually, even though I haven't yet found EconoKote locally yet, I have found some light iron on coverings which seem to fill the bill. In fact, I have found so many of them, that it will take me awhile simply to sort all of them out. I have also found several books on the subject, so I guess I am in a good position to keep moving forward with this project. Thanks for the help.