Acceptable aileron hinge gap for a Trainer?
#26
Senior Member
flynte,
You're one small step away from a very good hinging job.
You're using "hard" nylon hinges. Kewl.
Right now your gap is exactly as wide as the "hinge" part of the hinges. You got two different techniques that'll work.
It looks like the TE of the stab is square and the LE of the elevator is rounded. Those aren't the best profiles for the easiest built modeling zero gap hinge line but......... That's what you see a lot on "real" airplanes. But they have the hinge inlet into the elevator completely. No inletting into the stab at all. The hinges stick out there. Their idea is to put the CL of the hinges where the center of radius of the LE of the round elevator would be. The LE of the elevator then will rotate, but won't open or close the gap while rotating.
The easiest build for models.... Inlet half the width of the "hinge" part into the elevator and half into the stab and test the fit and freedom. It usually works out ok even with a rounded LE on the elevator. But it would have worked out really good had that LE been sharper and had lined up with the centerline of the hinges.
Hope this helps.
You're one small step away from a very good hinging job.
You're using "hard" nylon hinges. Kewl.
Right now your gap is exactly as wide as the "hinge" part of the hinges. You got two different techniques that'll work.
It looks like the TE of the stab is square and the LE of the elevator is rounded. Those aren't the best profiles for the easiest built modeling zero gap hinge line but......... That's what you see a lot on "real" airplanes. But they have the hinge inlet into the elevator completely. No inletting into the stab at all. The hinges stick out there. Their idea is to put the CL of the hinges where the center of radius of the LE of the round elevator would be. The LE of the elevator then will rotate, but won't open or close the gap while rotating.
The easiest build for models.... Inlet half the width of the "hinge" part into the elevator and half into the stab and test the fit and freedom. It usually works out ok even with a rounded LE on the elevator. But it would have worked out really good had that LE been sharper and had lined up with the centerline of the hinges.
Hope this helps.
#27
Senior Member
My Feedback: (4)
You beat me to the graphic Rock.
But he is exactly right, if the torque rod is not on the hinge line, there will be binding and twisting somewhere. Now, this is not to say that it won't work, because it will, but who knows what the consequences will be over the course of a few weeks, or months or years.
Eventually something is going to give out. A hinge could break, or the torque rod could open the hole it pivots in (Which could lead to flutter).
So I would definitely try to correct it before finishing.
But he is exactly right, if the torque rod is not on the hinge line, there will be binding and twisting somewhere. Now, this is not to say that it won't work, because it will, but who knows what the consequences will be over the course of a few weeks, or months or years.
Eventually something is going to give out. A hinge could break, or the torque rod could open the hole it pivots in (Which could lead to flutter).
So I would definitely try to correct it before finishing.
#28
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Joined: Oct 2005
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From: Alberta,
AB, CANADA
darock
Thanks for the pointers. I'll redo and inset 1/2 way on both. Just starting to mod the wing for ailerons so it'll be easier to do it right the first time
thanks again
flynte
Thanks for the pointers. I'll redo and inset 1/2 way on both. Just starting to mod the wing for ailerons so it'll be easier to do it right the first time
thanks again
flynte
#29
Thread Starter
Senior Member
I placed a piece of 1/16" balsa on and it was definitely not high enough so I started the job with a 3/32" strip which is now glued onto the back of the wing. It looks a lot better.
It looks just hairline high, so I will finish shaping the leading edge of the aileron and maybe lightly sand along the hinge line on the wing to ensure the hinge line won't be under the surface.
Thanks again.
It looks just hairline high, so I will finish shaping the leading edge of the aileron and maybe lightly sand along the hinge line on the wing to ensure the hinge line won't be under the surface.
Thanks again.
#30
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From: chatsworth,
CA
darock,
the easiest place for them to bend is not directly along the axis, but it is very close. if it were a sport plane or something, i would say that is un-acceptable. but fact of the matter is, it is a trainer. you will not have much deflection, you will not draw much power, centering will not be an issue and i can not remember a single instance where i have heard of CA hinges failing on a trainer type aircraft, namely for those reasons stating above
i however would not fly it in that state, i am just stating that it will work.
the easiest place for them to bend is not directly along the axis, but it is very close. if it were a sport plane or something, i would say that is un-acceptable. but fact of the matter is, it is a trainer. you will not have much deflection, you will not draw much power, centering will not be an issue and i can not remember a single instance where i have heard of CA hinges failing on a trainer type aircraft, namely for those reasons stating above
i however would not fly it in that state, i am just stating that it will work.
#31
Senior Member
TimePilot and flynte
You're welcome. It's sorta fun how easy it happens to be to do a better than "it'll work" job.
You're welcome. It's sorta fun how easy it happens to be to do a better than "it'll work" job.



