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Building Tips and technical articles. => Building techniques => Topic started by: Mike_Fitzgerald on December 05, 2015, 09:12:27 AM
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I'm building an Oriental from a kit and considering making the control surfaces removable...Which hinges would work? I have some Great Planes nylon hinges but can't get the pin out so I can replace it with a length of .032 music wire..Any info greatly appreciated..
Mike
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Get the pin out by grinding the head off with a Dremel cut-off wheel.
I like the DuBro hinges because they use a smaller pin, but that has nothing to do with pin extraction techniques.
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Got it! Thanks for the info...
Mike
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You're the second Idahoan I know of who flies control line -- I don't know if you're already plugged into the Northwest CL scene, but if you aren't -- welcome, and feel free to come out west & play with us. The local contest listings are at www.flyinglines.org (http://www.flyinglines.org).
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You're the second Idahoan I know of who flies control line -- I don't know if you're already plugged into the Northwest CL scene, but if you aren't -- welcome, and feel free to come out west & play with us. The local contest listings are at www.flyinglines.org (http://www.flyinglines.org).
Tim
Mike used to live in the Tri Cities when I first got started flying,,,
him, Joe Just and a few others,,, He went and moved to Idaho,, now he is down there with Pat Johnston,,
In fact I seem to recall he did attend a contest or two.I know he was at our Pasco contest,,
He had a pretty innovative aproach to the Rabe Rudder on his P-40 profile I think it was?
man its been awhile,, glad to see Mike still flying though
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OK, here is how I make removable controls. It so happens it is about time for me to make a fit up on my current project, and, I've been asked before how I do this. This has nothing to do with gluing, just the fit up. I'll make another posting on gluing, if anyone is interested.
To start with, the hinge slots need to be absolutely in line or you'll have a bad time later. I make all of mine (slots) by laminating 1/32 balsa between two pieces of balsa the appropriately thickness. This goes for wing TE, flap LE, stab TE and elev. TE. It takes a little extra time but makes for way fewer problems later on.
For pin removal I use small diagonal cutters. Not mandatory, but I trim all of the hinge bodies to just above the DuBro lettering and "dog ear" the corners. Everything should be de-burred before final assembly.
I don't install hinges until the painting and polishing is done. The very last thing is loops in the lead outs.
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In this case I used .025 wire for the medium sized hinges. You can use bigger wire but, it can be a problem when things don't line exactly right. What little bit of slop this creates is made up when sealing the hinge line later on.
I have used full size wire and drilled out the hinge barrel to fit. Seemed redundant to me.
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Hey Mike, I'd definitely like to see the rest of the story! Please post it when you can.
Thanks
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I like the Robart hinges.
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OK Tom, just for you and anyone else that didn't read my article in Stunt New a couple of year's ago. Here it is, pretty much verbatim.
"I decided to spend some time going through last years’ model and make some past due repairs and general maintenance. It’s a good thing I did! While cleaning and repairing dings, I had to remove the sealing tape on the control surfaces. Really, they should be replaced from time to time anyway. When I removed the tape from the outboard flap I discovered three hinges that had come loose from the wing. It’s hard to say how long they have been that way, but it looked like an accident waiting to happen. Repair in this case, is simplified by the fact all of my control surfaces are removable. I do it a little differently than most. I use two wires on each wing going from the middle of each wing toward the tip. My first effort a few years ago, I used the traditional method of one wire per wing starting at the wing tip and threading through each hinge. That’s fine except, if there is any misalignment it becomes difficult to thread a piece of .031” wire that is at least 25” long. Of course, perfect alignment cures that, but I find my way easier. Each wire is held in place bay a small piece of tubing recessed into the trailing edge.
As it turns out, it looks like I simple forgot to glue those three hinges during original assembly. No harm, no foul in this case because the sealing tape held. I glue hinges in with thin CA, a method I learned a few years ago form John Miller. First the hinge tabs need to be roughed up with sandpaper to give the glue some “bight”. Cut some heavy silkspan the same width as the tabs about two inches long. Fold the silkspan over the tab and push it into the hinge slots of the trailing edge of the wing. You will have pieces of silkspan sticking up on top and the bottom of the wing. Carefully apply a very small amount of thin CA to these pieces and will quickly wick into and attach the hinges permanently to the wing. Try it on a practice piece, you’ll find out that the hinge can’t be removed without taking wood with it. I have removed with “un-cure” before, but with a little care they will come out fine. Also, I should mention that it is a good idea to coat the barrel of the hinges with Vaseline or WD40. Again, if the hinges are sticky they can be freed up with CA debonder.
One other thing I do is drill out the hinges with a #60 (.040) drill and deburr all the edges after removing the existing pin. This may not be necessary but worth a try on a practice piece. It makes the hinges very free even after the sealing tape is applied and you will never notice the extra clearance in the fit. "
Note, if you are afraid of the CA method, use some other glue. The CA makes things really quick.
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Thanks Mike, excellent post (as usual). I like the silkspan trick, and have used it before and it took me a couple tries to get it right. What a surprise!
May I add:
On the Shark last year, with the hinges partially fit into the wing TE, I put lengths of 1/16 OD aluminum tubing between the hinges and ran the full span pins all the way through. Then, pressed the TE down on the work bench to align all the hinges and hot stuffed the hinges and tubes to the TE. The OD of the tubing matches the hinge barrels close enough that with the pin it's almost like a piano hinge, helping the alignment. The tubing weighs almost nothing and also helps alignment of the tape when doing that operation. I still got some stuff on a couple hinges, but maybe next time........
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What is Sealing Tape?
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What is Sealing Tape?
Clear ScotchTM tape -- and I put the TM in there because you really want to get that brand. Most people use the 3/4" wide stuff.
You apply it on the bottom side of your hinge lines to keep air from leaking through -- it can dramatically improve a plane's consistency and ability to hold trim.
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Mike,
Nice looking model.
Is that iron on covering?
Charles
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Hey Mike, I'd definitely like to see the rest of the story! Please post it when you can.
Thanks
Clear ScotchTM tape -- and I put the TM in there because you really want to get that brand. Most people use the 3/4" wide stuff.
You apply it on the bottom side of your hinge lines to keep air from leaking through -- it can dramatically improve a plane's consistency and ability to hold trim.
Boy you guys got some great tricks.
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No plastic, Charles. I don't even iron my clothes! It is assorted dope colors with automotive clear coat.
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No plastic, Charles. I don't even iron my clothes! It is assorted dope colors with automotive clear coat.
Mike,
You did a "GREAT" job with the color gradients. H^^
It's nice to see that kind of talant and quality in work.
Charles