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Building Tips and technical articles. => Building techniques => Topic started by: Bootlegger on January 30, 2013, 01:03:37 PM
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when you're installing a floating b/c in a foam wing how do you do it and why do you do it that way??e
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Floating bellcrank??
Please define.
The videos by Bob Hunt and instructions with his foam wings show very clearly how to install a light, simple, and structurally sound method to install a bellcrank in a foam wing.
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Keith, maybe I should have called a "suspended" bell crank. It has an upper and lower mount, and this particular one is going in a profile model.
Thanks for calling this to my attention. y1
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Tom Morrs in his bok shows how he does it. Also the bellcranks I have gotten show how to do it. There is a metal rod long enough to go above and below the wing at the mountg location. Tom Morris uses eyelets to center the bellcrank on the rod. J-B Weld is used to hold them in place. I do mine with wheel collars. Grind a notch for the set screw to fit into. The plywoo plates go on the surface of the wing top and bottom using epoxy glue. I also now notch the rod for the epoxy to grip after losing my Spitfire. Once the wing is in the fuselage, I cut the excess rod off almost flush with the ply wood. I then put another layer of plywood spanning the fuselage sides top and bottom.
There are probably better ways of doing it. Wasn't so lazy would go do a search for you. Z@@ZZZ
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when you're installing a floating b/c in a foam wing how do you do it and why do you do it that way??e
I just say "NO" to floating bellcranks !! ;D
R
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R, Then say "yes" to a suspended bell crank, and 'splain how to do it ;D
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R, Then say "yes" to a suspended bell crank, and 'splain how to do it ;D
I can't say how to do it in a foam wing, but I've seen pictures that make lots of sense.
Here's how you pretty much have to do it, in any wing:
- Install the bellcrank on a rod or bolt, so that the bellcrank is held in the center of the pivot. Lots of people use rods. So far, I've been using #8 bolts to good effect. I use bolt with a long smooth shank, with spacers to hold the bellcrank where I want it on the smooth shank. Lots of people who fly lots better than me use rods -- take that as you may.
- Install plywood (or aluminum, or titanium, or carbon fiber -- really, this is up to you) plates top and bottom that catch the spars, and that can hold the pivot in place.
- When it comes time to install your control system, put the bellcrank in place, shove the pivot through it (and through any spacing devices you may have -- devised), and fix everything into place
Once you have the bellcrank centered in the wing on a pivot, and the pivot firmly held in the wing, everything else is details. Have you tried digging through the various build threads to see how other people do it?