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Preferred Elevator Hinge Method?

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Old 01-10-2018, 04:50 PM
  #1
CLBetten
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Default Preferred Elevator Hinge Method?

I'm finishing my first .35 sized plane. The kit came with CA hinges. I'm tempted to use the "stitched" style string hinges to make the hinge more flexible. Any experienced suggestions?
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Old 01-10-2018, 08:50 PM
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All Day Dan
 
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Dubro makes hinges that are ideal for your application. Dan.
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Old 01-11-2018, 04:43 AM
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Well, CA hinges work very well. I have them on airplanes up to 50cc and have never had a problem. Dubro, Robart, and Great Planes all make good hinges, just beware that the trade off is that you may have to do some adjusting of the control surface and the trailing edge if you decide not to go CA. This is not a simple drop-in operation. For example if you use a hinge (Great Planes/Dubro) with that little metal rod in it, you will need to trim each surface to recess the hinge joint. Otherwise you will have a large hinge gap along the length of the elevator that may need to be sealed. But none of these are complex operations. But all of these work better before you cover or paint your airplane. One thought is to just go with the CA hinges and work the joint back-forth gently a couple of dozen times. This will loosen up the surface. You don't need to have complete 100% friction free "flopping" for things to work right. Just make sure you use the appropriate slotting tool for the replacement high you purchase. Makes life much easier.
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Old 01-11-2018, 06:32 AM
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I like the fabric hinges, and use a nylon/polyester shirt like material. I glue it on criss cross with Sigment usually. It is a bit hard to use shrink films that way because it goes directly on to the balsa. Monocote hinges are ok too, but not as strong. I criss cross those too, overlapping 3/16" in the middle. They both give a nice free action.and look better than sewn hinges which I find that they always shift.
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Old 01-11-2018, 07:52 AM
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CA hinges can be stiff, decreasing the smoothness of control inputs. I like either the pinned hinged flat nylon or the Robart hinges.
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Old 01-15-2018, 01:17 PM
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Lou Crane
 
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Thread hinges can be the freest and have absolute minimum gap between fixed and moving surfaces. They are not particularly 'pretty,' tho.
The kind I refer are actually thread, sewn through holes punched by the sewing needle. These are also called 'figure-eight' hinges. because the thread travel forms a Figure-8.

Example: stab to elevator, wood sheet surfaces: thread the needle with heavy button thread. Between 1/4" and 1/2" from the hinge gap, push the needle through, say, the stabilizer, from bottom to top. Pull enough thread through so you can lead the needle over to the hinge gap and pass the needle down through it. Go about the same distance from the hinge gap onto the elevator and push it up and through. Continue this pattern of over-and-under "stitching" separated about 1/8" until you have say 6 or so passes through the wood. The surfaces should be in contact at the gap line and the thread pulled firmly taut. NOT too tight, but snug so the surfaces stay in line. Snip off the thread where it comes out. A drop of CyA, or even model cement on the pierced holes and the end will keep things honest. Button thread shouldn't become brittle even after doping over it. These do last. They strengthen the surfaces they're on.

Sew another sequence a few inches away. You don't need more than two or three such hinges on each side from center.

Last edited by Lou Crane; 01-15-2018 at 01:22 PM.
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