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General control line discussion => Open Forum => Topic started by: Shorts,David on July 31, 2021, 05:37:31 PM
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Okay, there was a thread where you master builders talked about how you do hinges. Now, so I don't sound like a total incompetent, when a plane is done, I turn it on wingover position and hang a tiny weight system I made from each of the leadouts. This ensures very smooth motion.
But, I've had to go through my hinges over and over to find and work on some until they are smooth.
I think a few of you said you cut the pins out and replace them? Seriously? So, is there a good video showing this? Do you put in one full length piano wire, or individual for each hinge? Do you fit them first, glue them in, and then remove the pins? Or...
I've also got some dubro heavy duty hinges with the pin already removed. Do you use these?
Thanks for any help, maybe there is an easier way than what I've been doing.
I'm staring at my new classic plane now. I was going to test fit all surfaces, make my pushrods, then take it apart for covering and painting.
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Robert, has an excellent hinge system he developed.
I've seen his video on this. If I wasn't so lazy or cared more about my models, I'd tackle his method. It's something to behold.
However, I'm lazy and still use Klett nylon hinges. I recess them 50% on each side, when I'm done you can barely see the hinge.
Some guys notch out the flap and elevator. This allows you to see the hinge. Brodak's Smoothie comes with notches in place for hinges.
CB
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I think a few of you said you cut the pins out and replace them? Seriously? So, is there a good video showing this? Do you put in one full length piano wire, or individual for each hinge? Do you fit them first, glue them in, and then remove the pins? Or...
When they were available, everybody used the Klett brand hinges, that came with loose leaves and the pins not installed - so never install them. Most others, you have to cut them out, then you have the loose leaves. Most of the others also require you to remove abundant molding flash around the barrel.
Once you have it done, and are ready to install the hinges, use a single pin the same size as the original (1/32" for Klett, and presumably DuBro (but measure it)). Install them with the pin in. When the glue dries remove the pin and you can remove the flap/elevators, too. Clean up any squeezeout. When you go to fly it, use a single pin the next smaller size down, I use .025 since it is easily available in straight pieces. This gives you some slop, which will free up everything. Put a 90 degree bend in the end and use clear tape to hold the pin in, then put in the seals.
Normally I install the hinges, and the seals, as the very last step, after the airplane is fully finished and ready to go. That way you don't have to worry about cleaning the paint out of the hinges, and the thickness of the paint doesn't reduce the clearance between the flap and the trailing edge.
Of course, make the horn a slip fit into the control surface, so you can remove the surface later. This has saved me several times when I could repair or replace the flaps for performance reasons, and I have 3 sets of flaps for one of the airplanes. The flaps were off the current airplane two days before we left for the NATs this year, while I was refinishing them after modifications.
Brett
p.s. without "engaging" further, I strongly recommend *not* recessing the hinges or hinge pin into the flap or trailing edge, or at least, making sure the leave is recessed just enough to get the barrel of the hinge, the outside part, even with the TE. IF you recess it, it makes applying the seals much more difficult or impossible without binding it all up. You *do not want* the pin to wind up binding on the surface, it has to float between them, even if it swells up a bit from humidity later. There is a little chamfer where the barrel meets the leaf, that, you can push into the wood.
p.p.s. I usually give credit for ideas I steal, in this case, Paul Walker.
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Here is a step by step process which I have copied and find works extremely well.
https://stunthanger.com/smf/gettin-all-amp'ed-up!/2016-electric-stunter-build-log/msg435293/#msg435293
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https://youtube.com/watch?v=ZyIfgm7O4Rc&feature=share
I think Charles was referring to this video that I posted a few years ago.
I’ve done some minor refinements since but the method works quite well and quickly.
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I developed a method of making hinge pockets centered on the flap/elevator. Use two pieces of balsa 3/4 inches wide and half the thickness of the main part. 1/4 inch flaps use two pieces of 1/8 x 3/4 x flap length. Mark the hinge locations and sand the hinge slot into the two pieces of balsa. Glue the two together and then glue to the flap. For a kit you must cut 3/4 off each flap leading edge or figure it in for a scratch build. I use the same process for the wing and elevator trailing edges. The hinges always come out dead center. I make the wing trailing edge full length with rib notches, just like the old days.
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https://youtube.com/watch?v=ZyIfgm7O4Rc&feature=share
I think Charles was referring to this video that I posted a few years ago.
I’ve done some minor refinements since but the method works quite well and quickly.
Robert,
Wrong Robert.
I was actually referring to "Sparky." You have to see his video to see and appreciate what he came up with, for a hinge design. State of the arts.
I would never "cut" that is, notch a flap or elevator to accommodate a hinge and I would never use a long wire also. But that's me.
David, I suggest you do your homework and do a bit of research, also, view a few models. This is an important decision, so...
Choose wisely.
CB