Monokote hinges

Several years ago I had to replace a wing on my Big Stik 40. I bought
a foam wing and partially sheeted it. I didn't feel good about making
slots in the small trailing edge balsa for hinges so I made hinges
from the Monokote that I was using for covering. The wing was white
on top and red on the bottom, so I made each hinge multicolored
Monokote. When I was done I had almost no open area between the
aileron and the wing (because I made a lot of hinges). I have been
flying it for quite some time and think it is a great hinge job.
There is no play in the aileron yet it swings freely.
Van
Reply to
vangelisobi
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Monokote hinges are quite common in gliders. I guess you've proven that they work in a Big Stik too.
Reply to
ahdofu
Many people use them, although the majority do not. Done right, they work great. Done poorly, they fall apart in short order.
Reply to
mjd
_____ Rather than individual hinges I bevel the control surface ____/ and place a strip of Monocot, the length of the control surface, on top. Then I bend the surface all the way back and place another strip on the bottom. Invisible, low friction hinges with no gaps. Easy to do and you *can't* pull them apart without damaging something.
Reply to
Ed Forsythe
Ed, is there anyplace we can see the bevel and the way you fit the Monokote to both control surfaces. Does the Monokote on top touch the Monokote on the bottom through the hinge gap?
Harlan
Reply to
H Davis
"H Davis" wrote
I have also done hinging this way.
There is no big difference in how they would be beveled, from a hinged application. The monocote does not really touch on both sides, but perhaps a very small amount. Too much would let a possible flutter situation develop.
I have also done things slightly different. In this manner, you make two strips of monocote per hinge, and remove the backing. You put one adhesive up, and one down, aligned out in a straight line. Overlap the two about 1/2" and heat the overlap, so they stick together.
Use two of these assemblies in pairs, one starting on stuck to the top of the wing, running through the gap, and stuck to the bottom of the aileron. Use the other assembly right next to the other, but run it from the top of the aileron, to the bottom of the wing.
Do this in several places down the length of the wing. Then as you cover, fold the aileron all of the way back laying on top of the wing, and cover the bottom of the wing and aileron at the same time, continuously. Turn it all over, and cover the top of the wing and aileron at the same time. This part is just as the OP suggested. My change only helps reinforce the joint.
Reply to
Morgans
I have used monokote hings with great success. In the original Top Flite videos on using monokote, there was a full demonstration of how to do it and how to apply them etc. It was done by Charlie Baeur who is, I think, and AMA VP now. You could contact him about a copy maybe.. Frank Schwartz
Reply to
Frank Schwartz
Frank:
As a matter of fact, I will see Charlie this weekend and will ask him which video it is. I'm sure he's still selling copies of the videos. I know he was earlier this year. Charlie is our regional AMA director.
Thanks for that information.
Harlan
Reply to
H Davis
Yes it does Harlan, although the contact point is extremely narrow. The bevel is about 45 degrees an goes from the bottom of the elevator to the top. I don't know where you can see it but I have a sample a friend gave me years ago. If you like I will slice off a section and mail it to you just email me your address. BTW, it's difficult to describe but it's really quite simple
Reply to
Ed Forsythe
Not too hard to describe. Instead of sanding the front edge to a V shape with the point on the center line, sand a single faceted bevel so that the top edge has nothing removed. In other words, the elevator contacts the stabilizer only at the top edge, and the bevel goes down and back at 45 degrees.
Iron a piece of monokote on top so that it bridges the elevator and the stabilizer. Then turn the assembly over and iron another strip on the bottom. Your balsa parts should be pushed together, but there will be a little gap about 1/32" where the top and bottom monokote touch each other. This keeps the film from pulling off of the wood.
In the real world, this kind of hinge is very good and it works well, but after you fly the plane for a season the edges will start to tear and you will probably have to remake the hinges.
Reply to
Robert Reynolds
Excellent description Bob with one exception. You don't "..turn the assembly over and iron another strip on the bottom." Actually you bend the two surfaces back over themselves and ... the heck with it I'll just send Harlan a sample ;-)
Reply to
Ed Forsythe
I don't bend it all the way over, I usually bend it enough to make it flat across the bottom, or maybe just a bit farther.
One other thing: When you cut your strips of Monokote to put on the top and the bottom don't forget to make all of the corners round instead of pointy. That will help to keep the edges from coming up.
Reply to
Robert Reynolds

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