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Old Mar 12, 2003, 09:50 AM
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LawrenceHare's Avatar
USA, MD, Bethesda
Joined Nov 2001
480 Posts
Hinges

I confess to being a little paranoid about hinges since Gertie's SwitchBack lost an aileron last year, whizzing at great speed upside down poor Gertie ended up clobbering the ground suddenly and hard! Fuselage was a total loss but as Mountain Models sells piece-parts of this plane, I was able to get just the fuselage and she will be up and around anytime the weather permits, along with a few hours aforehand... The reason was I used a technique I used in my silk and dope days, that is to extend the covering to the control surfaces so it functions as hinges. I did the same with the Solite I used, think it was Solite, and rather than extend the covering from the wing, I added a piece for hinging purposes. MISTAKE! I thought it might be a bad idea at the time, not enough adhesion surface, but the doubt got lost in the general doubts and questions of flight preparation.

So I was thinking of using CA hinge material for my Bristol Scout. I have a sheet of this and made up a couple of hinges and slots for one of the ailerons, as this Scout, which is Peter Rake's design, will be aileroned. Seems very good, very secure, but rather stiff I thought. So I went to the lhs looking for a lighter CA material to use, which naturally they had none whatsoever of any thickness at all.

Peering around at all the stuff they DID have I found some packets of fiberglass strips, about two inches wide and of various lengths, and one package had a picture on the back stating that the contents made the very best of hinges. I was unsure of this but bought a two-dollar packet to try.

At home, I cut a piece about half an inch by the full width and found, as I feared, that is de-stranded rapidly and was too floppy to slide into the slots I had cut. As an experiment I rigidized it by squirting a light covering from a spray-can of craft spray-on glue. Now it seems stiff enough to be cut to its final shape without falling apart and then to be easily inserted into the slots. It is also much more flexible than the CA hinge material I have and it is lighter to boot.

My question is what do the honorable ladies (are there any?) and gentlemen on this forum think of this idea? Is fiberglass a reasonable material for hinges or will it fall into its component parts after some use, perhaps causing the plane to follow suit? Also, treating it for its lack of stiffness in this manner; is that going to cause problems down the road? I will place the hinges into their slots once ready and whick in some light CA to afix them permanently. Will the stiffening treatment cause this to be a potential source of failure perhaps?

Thanks - Lawrence
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Old Mar 12, 2003, 12:47 PM
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Re: Hinges

Quote:
Originally posted by LawrenceHare
...
My question is what do the honorable ladies (are there any?) and gentlemen on this forum think of this idea? Is fiberglass a reasonable material for hinges or will it fall into its component parts after some use, perhaps causing the plane to follow suit? Also, treating it for its lack of stiffness in this manner; is that going to cause problems down the road? I will place the hinges into their slots once ready and whick in some light CA to afix them permanently. Will the stiffening treatment cause this to be a potential source of failure perhaps?

Thanks - Lawrence
No, fiberglass will not make a good hinge at all if you are relying on it to flex. It will simply crack apart very quickly. The CA hinges can be cut to narrower sections for use in smaller models. It works fine and is not too stiff when sized appropriately. For small models I also pre-bend the CA hinges several times by folding them double and making a crease at the hinge line before installing them.
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Old Mar 12, 2003, 01:19 PM
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Portland, Oregon, USA
Joined Jun 2001
623 Posts
Floppy disk hinges

Seems like I've been preaching about these lately. I didn't come up with the idea though.

Take apart a floppy disk and then cut the actual disk material into hinge-size strips. Then just treat like CA hinges from there on out. I think they're a little thinner, and more flexible. And free, cuz if you're able to get on the e-zone you probably can find some floppies.

-Todd
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Old Mar 12, 2003, 02:33 PM
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USA, MD, Bethesda
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Thank you gentlemen, valuable advice. I read about the floppy thing Todd in this month's, March, RC Modeler, page 97. I even have some old eight-inch floppies - shows how far back I go! Whole bunch of hinges in them things...

Cheers - Lawrence
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Old Mar 12, 2003, 04:24 PM
Visitor from Reality
United States, VA, Arlington
Joined Dec 1996
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Hi Lawrence

For my little bitty planes, I use 3M "Scotch" crystal clear tape! This is 3/4" wide and has worked well for me over the last few years. Bigger models, I've cut regular 2" parcel tape down in width some - use the good 3M stuff that tears across its width easily, rather than cheapo stuff you have to cut with knife or scissors.

Other methods - on Monokote, or Econokote covered models, I'll use the same stuff I covered it with as a hinge. One of these came unstuck after around 3 years "in the field" last year - and I had a heck of a job getting the above crystal clear tape to let go on the elevator hinges.

"Solite" struck me as far too light and low temp to be safe to use as hinges. My Switchback has the above office tape hinges ...

The regular CA hinge stuff is pretty thick - I have some thinner ones I hauled over from England and am doling out in niggardly fashion to suitable candidate models.

I recently had the pleasure of cleaning up the mess left after the most expensive and dedicated hinge tape I ever bought fell off Less than a year old, it came from a dedicated to modelling mail-order house and was sold for hinging. After less than a year in service, I noticed a blemish on the corner of an aileron hinge. When I poked at it, the entire aileron wide length of tape about came off in my hand, leaving the glue behind. It took about a night of solvent and scrub to remove the residue. Motto - spending a lot is not always a solution to a problem.
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Old Mar 12, 2003, 05:43 PM
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Aylesbury, Buckinghamshire, Great Britain (UK)
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Lawrence,

Try mylar draughting film cut into strips and CA'd into knife slots - always works for me. If you are really worried, you can push pieces of pins through the balsa and hinge for security.

I also use the crystal clear tape that Dereck is refering to with great success, but this is propbably not going to look too good on your Scout.

Mike
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Old Mar 12, 2003, 07:06 PM
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St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
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Southern R.C. cy hinges.. They come in 1/4 scale size & a smaller very thin. Cut the width to suit the flex needed. Use them on small Guillows cut 1/8"-3/16" wide.
Using them for years, never had them pull out. Have had hinge lines left intact after a total crash. They are blue-green in color, I believe they were the first on the market.
Steve
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Old Mar 12, 2003, 09:05 PM
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Pittsburgh, PA
Joined Jan 2002
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Quote:
Originally posted by LawrenceHare
.... old eight-inch floppies ...Cheers - Lawrence
Golly, I'd stay away from those, they're probbly dry-rotted or oxidized by now. What're they 30-40 years old by now ?
-Mike
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Old Mar 13, 2003, 10:56 AM
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Thank you gentlemen, once again I am delighted with this forum! I am installing pull-pull on the tail feathers and was looking for a sturdy hinge that would act as a central fulcrum and be able to resist the pull, hence my thoughts about the CA hinges. I have tape on my ancient ratty old foam Tiger Moth, which still flits around as happy as a clam - which were they to fly I am sure they would be. And also on my Tipsy Nipper which was an ARF and seems mighty sturdy.

I was interested to see that you use Monokote, or Econokote, as hinge material Dereck, this was my thinking with Solite. Had I extended the actual wing covering I might have been fine perhaps, especially if I had put it on top AND bottom; I just added a strip though on top of the aileron covering and it had nowhere near enough adhesive surface. Live and learn!

Mike, I have a stack of eight inch floppies here and this one is labeled CP/M ver 2.2 CD110 type 3 - 721, 08/16/84 - Ahhh, what delightful times! So nearly twenty years old. No readers outside of the Smithsonean though and I doubt they work! The material looks good. Anyway, for historical reasons I shall keep them as they are, along with my core memory and other relics of my age!

Thanks folks - Lawrence
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Old Mar 13, 2003, 11:24 AM
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Houston, Texas
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Another option is Tyvek envelopes from the Post Office, light, strong, and free
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Old Mar 13, 2003, 04:39 PM
Trampling out the vintage
Joined Feb 2002
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I built the Rake Bristol Scout last year and to my knowledge am the only one who put ailerons on. I used trimmed CA hinges using Gerald's method and they worked great. After installation spend another 10 minutes flexing them and you are done.
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Old Mar 13, 2003, 05:32 PM
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Brum UK
Joined Jan 2001
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Is fiberglass a reasonable material for hinges or will it fall into its component par

Glass fibre is fine for hinging, just depends on what you fix it with. I have used Acrylic varnish to hold glass cloth to depron for 400 / 600 models and they have had no problems at all. They have come loose with significant impact, but so did a lot of other things. The acrylic varnish is not ridgid like cyano, the slight flexibility makes the glass cloth work well. Glass hinges are used in plenty of molded models.

mike
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