Cloth Hinges...Hope I haven't over-cooked the topic

LAST EDITED ON Jul-24-04 AT 01:22 AM (CDT)
 
Had some trouble with getting the pictrures up. Think I got it right, now. Sorry.

Had to go to a wedding today and took the day off. Decided to do a little work on my latest model with the extra free time. I am so pleased with the method I have been using, decided to post a few pictures of mounting the hinges. This method has worked so well that I find myself wanting to show others how to do.

Surface prep is three or so coats of clear, sanded lightly in between coats. Then cover with 00 silkspan. Covering first seems to provide a more porous surface and the hinges stick down better.

I use taffeta. Cut it into strips a little larger than needed. then dope it down with a couple of coats of clear. Just lay it out on a smooth surface and brush on a couple of coats of clear. Once dry, peel in up. The material won't fray nearly as much when you cut out the hinges, now. Having dope already on the hinge material also seems to help in making them stick down. I plan out the size and number of hinges. Then put guidelines on the stab. This keeps things straight. I don't know about anyone else, but just "eyeballing" it never cuts it for me.

Apply clear dope to the stab where the hinge is to go. Line the hinge up and stick it down. Brush a little more dope or thinner on and smooth out the hinge. I put all of the hinges on the stab, top and bottom. Wet the hinge material with dope/thinner and try to get the hinges to curl towards the direction they will have to go on to the elevator. Let dry. I use two balsa sticks with rubber bands around them as holders and slide them on the stab and elevator. See pictures. Slide sticks holder over stab and elevator. Stick ‘em down on the elevator in the same way.

Works great!

I like the rubber bands/sticks idea for alignment...thanks.
--Ray

I like the idea of covering the cloth with clear and letting it dry first. It should be much easier to make hinges. Cover a good size sheet of cloth then cut out hinges after its dry. No waste and no threads hanging out on the edges. It will probably be much easier to cut a straight line too.

Gary,

Never tried doping a large piece. Might work okay. I would suggest ironing the mateial flat. Set the iron at a relatively low temp because the taffeta wil melt. My wife does a lot of quilting and has the hot set up for cutting the cloth into strips. She uses one of those wheel cutters that looks a lot like a pizza cutter. She cuts them on one of those padded mats with one inch lines on it. I tried using it once and decided I was better off to let her cut it. She can cut a yard of the taffeta into inch and half inch strips in about ten minutes.

I learned of doping it first totally by accident. First time I tried to use this method, I didn't prep the surface or dope the hinge material. The second time around, I used the same material over again and that's when I found out doping made it easier to cut with no frays and it stuck down a whole lot better. Been experimenting with different techniques since.

Jim Lee and an article in Stunt New by Ted got me started doing it this way. It really does work well and if you plan it all out ahead of time so you get things lined up and the hinges the right length, it looks nice, too.

I would caution that you sand very lightly at the edges where the material goes around the corners. It's easy to sand right through the material. I just sorta brush that part with 400 paper. After a few more coats of dope, the surface lays pretty flat and smooth.

They do last. I used them on a Ringmaster that I put a lot of flights on. Lasted over four years without any signs of wear and tear. I have yet to have an airplane outlast the hinges.

Regards,

LAST EDITED ON Jul-26-04 AT 09:53 PM (CDT)
 
John: Dumb question time: What do you put the taffeta on so that it won't stick when you dope it? Waxed paper? Neat idea, I will try it. Izzat a Flite Streak tail feathers? Thanks

LAST EDITED ON Jul-27-04 AT 06:14 PM (CDT)
 
Hi Carl,

No such thing as a dumb question. I tried using wax paper a couple of times. It works okay, but this last time I just laid out the strip on my dry wall cutting board and painted it on. Peeled it up just before it had dried completely. Seemed to work just fine and easier than separating it from the wax paper. See first picture above and the one down below.

Yup...Building another Flite Steak. Built one last year before the craze hit with the ARFs. It's a long story, but the garage door got it a couple of weeks ago. Had a nice running Red Head 35 on it and it flew very nice. Gave it to a fried to fix up for his nephew.

This one (see pic below) I made a few changes. Added about an inch and a half to the back end of the fuse and about a half inch to the nose with doublers that extend back farther. With the longer nose can use a two wheeled landing gear. Increased the stab area some and am using wing tips from the Combat Streak. They are more rouned and should be easier to cover. Got an adjustable leadout guide, too. Planning to paint it up like a jet with silver/gray.

Will let you know how it comes out.

Regards,

>I like the idea of covering the cloth with clear and letting
>it dry first. It should be much easier to make hinges.
>Cover a good size sheet of cloth then cut out hinges after
>its dry. No waste and no threads hanging out on the edges.
>It will probably be much easier to cut a straight line too.
>
>Gary Weaver [email protected]

Sounds like this might be another good application of PC...

Cloth hinges, In my opinion, are still easier than trying to align those R/C pin hinges without binding. I use Rayon Taffeta from the fabric store. I use it without first doping it, and I stick it to bare balsa with Ambroid. Once covered with silk or silkspan and given a few coats, the tape tends to disappear. If the tapes are put on more or less continuously, there is no need for sealing the hinge lines. This alone makes for a free-moving control system.

>Sounds like this might be another good application of PC...

I wonder. Applying the dry hinges with PC might work, pre-treating them might not. The dope works because it dissolves partially when it comes into contact with liquid dope and thinner when you apply the treated hinges. I'd be very surprised if PC behaves the same way.