"Hinges"

[Dennis Leonhardi]

Looking through some old plans recently, I came across an idea I've never seen for hinging the stabilizer and elevator … Each consists of two pieces, top and bottom.  A piece of material (linen) is glued between the top and bottom of the stabilizer and elevator.

Result: virtually gapless "hinge line".

Looks interesting!  Has anyone here seen it or tried it?  What material would you use?

I'd post the illustration here, but naturally I've forgotten which of hundreds of plan files it was …


Dennis

[Dave Hull]

I think I've read old magazine ads that showed something like you are describing. Somewhat similarly, a very old Stanzel Raider kit has a full length fabric strip glued along one side of the stab/elev. (That kit, by the way, is amazing in the level of prefabrication and exceptional quality.)

If you go the whole length, you need the hinge to be very flexible, so use a thin material. If I was going to give it a try, I'd start with a strip of polyspan. Because there is so much total hinge length it should be quite strong as long as there is no tendency to propagate a tear. The random fiber orientation should be perfect in that regard. I think Tyvek would be too stiff for a continuous hinge, but works for segments and of course, is nearly indestructible.

I would not use any type of linen or cotton fabric. It absorbs paint and becomes brittle. That also stiffens the hinge. When you flex it to free it up you are actually damaging the fibers as they break loose. It will also rot over a long period, should your masterpiece survive until that day.

If you are looking for other alternative hinge concepts, you should check out a really good sewn hinge using a stab/elev construction designed to accommodate this. They can look pretty good--in some cases barely visible.

Dave

[john e. holliday]

Can't remember the kiy, but this is the way the stab/elevator were hinged.  I tried it and never again as the dope made for very stiff controls and the hinge didn't last that long.  Yes it takes time but the over under cloth hinges are the way to go.   

[Ken Culbertson]

I have used Mylar exactly this way on sailplanes.  Gapless and very little friction.  Not sure if it would withstand the wide control range of a PA though.

Ken

[Mike Griffin]

Eric Rule used satin ribbon.  You lay two pieces of ribbon on top of each other and sew right down the middle. This creates a pocket for the elevator to slip into and a pocket for the stab to slip into.  You simply glue the ribbon on the top and bottom of the surfaces.

Mike