Better hinges.

LAST EDITED ON Feb-13-04 AT 12:53 PM (CDT)
 
I have been thinking there must be a better hinge. Plastic hinges are a pain in the butt to cut slots, attach with tooth picks, glue and sand, it takes a lot of time and work and they are not very strong. Old style cloth hinges are not very attractive but are strong. I came up with this idea and just finished the hinges on my new airplane. The Plans call for 1/4" balsa on the trailing edge of the wing, flap, stabilizer and elevator so I used 2 sheets of 1/8" balsa to get 1/4". I attached the 2 sheets of 1/8" together with pins and clamps then sanded the edges round. I removed the pins and inserted a sheet of nylon cloth in between the 2 sheets of balsa then glued them together with CA glue leaving half the cloth hanging out. I cut the nylon cloth 1" wide 24" long with a razor knife and a straight edge. The first hinge I made runs the full length of the elevator and stabilizer 17" long. I removed the pins on the elevator and put the nylon inside the 2 pieces of balsa and glued it together too with CA glue. The finished hinge is invisible because its inside the center of the balsa. It looks like the elevator and stabilizer are up against eash other but it appear like nothing is holding them together. If you look very close you can see the cloth in the crack. The hinge works perfect. I did the same thing to the trailing edge of the wing and the flaps only this time I use nylon cloth pieces 1"x2" spaced 6" apart. It works perfect too. It sure was easy to build and it looks great and works good to. I am getting a 45 deg angle movement up and down.

Some people go further (overboard?) and use woven kevlar,
well stretched.

how about some photos!

>how about some photos!

Well, here's a link, http://www.charlesriverrc.org/articles/construction/markdrela_clothhinges.pdf

According to Pacer Industries, CA will make nylon brittle with time, including hinges, horns, etc. and I assume nylon cloth.

I wonder what CA hinges are made of.

Are over/under hinges made out of cloth all that unattractive? I remember Ted Fancher posting a picture of some on a new plane he was building not too long ago.

I have for quite a few years been using floppy disk material for hinges. I started out using it on only smaller planes. Eventually using it on everything up to .40 sized planes. Take a floppy disk rip the case off of it and rip the disk material I dare ya Even bend it around a few hundred times and try to rip it. Its sad AOL now send CDs instead of floppies I no longer have free hinge material compliments of aol.

I cut hinges the same size as ca hinges I then heat a needle and poke some holes in each side of the floppy hinge then I use the ultra thin ca and ca them in just like any other ca hinge. Practice on some scrap a few times and test them for yourselves. I have yet to have one fail.

Gary,

You're approach sounds great. I've been cutting ripstop nylon kite material into 1" x 2" pieces and gluing the hinges on with Ambroid. If the glue gets into the fabric someplace you don't want it a little acetone will take care of it. The nylon is thin enough that there are barely any visible bulges where the hinges are, but with your method there won't be any at all.

There are some products out there which mimic Gary's approach. One is an extruded length of hinge material designed and produced by Ralph Cooney of Fourmost Products. I have for years wanted to fiddle with this stuff on a CL Stunt model.

But I like the installation process required for pinned hinges. And the resulting action, low friction, a very high degree of reliability, the relative ease with which I can have removable surfaces, not to mention a huge supply of the things(!) means I will continue as I have for years.

For me, this is a solution to no known problem.

Preston,

I get kinda nervous when you begin spouting off about non-Combat stuff. Is Rush fixing to use trick hinges on his next Impact, expected roll-out mid-2007?

>I get kinda nervous when you begin spouting off about
>non-Combat stuff. Is Rush fixing to use trick hinges on his
>next Impact, expected roll-out mid-2007?

Don't be nervous.

I have done exactly what you have done and the silk failed after a few seasons because the CA made the silk brittle. I know use an Ambroid like glue in the same way and that seems to have taken care of the problem. It also means you don't have to seal the hinge line with unsitely tape as well!

When finishing, how does one keep the paint out of a built-in continous hinge?

Same way you keep it out of an "over/under" hinge.

Just another thought... I've heard of folks using TYVEK for ultra thin "over/unders". You know, that stuff they make unrippable bags and envelopes out of. Never used these on a plane but did try on some scrap once. Looked very workable...

Anybody tried this method? I haven't (yet) but will. The author uses antique solartex which is reputably virtually invisible and makes a good hinge. This plan is from a model with 60 sized engine.
Adrian