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Building Tips and technical articles. => Building techniques => Topic started by: Bootlegger on January 01, 2017, 10:45:32 AM
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I am looking to do some wing building on a rod type jig, what have you fellows found to be best fir this purpose??
Some of the wings will be tapered and some will be straight.
Thanks a lot...
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Watch Sparky build a wing with a rod jig.
https://youtu.be/_dDj3azmUOI
You have to put up with all of us yakking and working in the background, but he blows through it in a hurry. An earlier video details making the ribs, but he basically assembles this wing in a couple of hours while chatting with us guys in the hangout. In a later video he glues the two halves together off cam, and then shows us how to finish the construction.
Rusty
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And notice how simple the jig is -- as long as you have a flat building bench and some dead-straight rods, all that you need is a set of blocks that match one another perfectly. I hadn't seen Sparky's T-section aluminum before, but I may adopt it for my next build.
It looks like Sparky uses aluminum rods -- I use carbon fiber rods ordered online from a kite shop, because I could get them long enough to build the whole wing in one piece. I got the ones that fit the jig holes in Brodak ribs, and then I got a matching Forstner bit from Amazon for scratch-builds. I'll probably keep using the CF rods, because they'll either be straight or broken, while aluminum may get bent without me noticing.
I also support the rods more thoroughly than Sparky does -- anything you use will sag in the middle; assuming a nice flat bench, more support blocks means a straighter wing.
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Someone asked for pictures. Here's one, from this build thread (http://stunthanger.com/smf/open-forum/legacy-build/).
The rods are 8mm, from https://goodwinds.com/ (https://goodwinds.com/). 8mm is close enough to 5/16" that it makes no nevermind for woodworking purposes, so the "matching drill" is a 5/16" Forstner (I suppose I could have found a metric one).
(http://stunthanger.com/smf/open-forum/legacy-build/?action=dlattach;attach=157804;image).
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It looks like Sparky uses aluminum rods --
I wann a say he used Arrow Shafts on this.. I dont remember
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I just scanned back through it. They were aluminum rods. We got off to a herky jerky start but it turned into a useful hangout. He got a lot done on that wing. Gave me the illusion I could run out to the shop and toss my wing together. Ha, right. I also learned I need to quit eating Mike & Ikes on camera.
Also, that feedback we had... turns out that we were listening to the delayed Youtube feed a member had turned on in another tab. If you start watching on the Tube and then decide to join, you need to kill the Youtube feed before going live.
Rusty
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I'm surprised that nobody has mentioned the Brodak wing jig, BH 1000. The tubes are 5/16" dia, 5" apart and 36" long so it can cope with wing panels about 34" long.
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I borrowed a jig from a fellow club member when I built my Legacy 40. He used 5/16 stainless steel rods, full length of the wing. The rods are a little heavy so he built two more supports to support the whole wing without any sag. Came out dead straight with no hassle of having to glue two wing halves together. I've heard this can be a royal pain to accomplish.
Rich
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I borrowed a jig from a fellow club member when I built my Legacy 40. He used 5/16 stainless steel rods, full length of the wing. The rods are a little heavy so he built two more supports to support the whole wing without any sag. Came out dead straight with no hassle of having to glue two wing halves together. I've heard this can be a royal pain to accomplish.
Rich
I considered rods, but the only thing rods gain you in a wing jig is weight -- 1/32" wall 5/16" tube will be something like 80% as stiff as a rod (someone who actually has the numbers at their fingertips can correct me on this, if they want to). Now, if you happen to have some rods around already, there's no need to not use them -- I looked into all the materials I could before I settled on CF, and it looked like they'd all sag a bit, and need some middle support when the wing was on.
And yes, having long rods does ease up the task of joining the wing. You can use short rods to join up a wing, too -- build each half separately, and before you put the tips on, use the jig rods to hold the halves in alignment while you join them. If you don't have a lot of room in your shop this cuts down on the inconvenience of maneuvering around a humongous wing.
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Tim, Thanks for the info that you sent to me, I sure do ppreciate it...
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I bought the Brodak jig to assemble the B-25.
I upgraded the jig in several ways.
Note the wheel collars and tip-bolts. This sure beats clothes pins and masking tape.
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WOW! :o
Some great ideas here! I really like the idea of being able to flip it over or hold it straight up. y1
Looks like I have a use for those 48" alum. rods that were going to be the LE's on a racing glider I was designing............... waaaay back when!
Good thread guys, Jerry
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Pat Johnston sells a rod type wing jig for $15. Uses 5/16 c/f arrow shafts.
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You can also buy brake line tubing at most auto parts stores for fairly cheap prices. I like tubing because you can "bore site" them to make sure everythings straight and true whenever you use them. H^^
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Glen I nearly spit coffee through my nose thinking of Brake line until my brain engaged and remembered the stuff can be had in larger than 1/8th inch diameter....but initially I thought you must be nutz.....grin
I have and used both the Pat Johnston jig and Brodak jig using easily sourced very straight arrow shafts
Originally I thought of trying to get the Adjusto jig but much too fiddly for my mostly profile building
I set up the Pat Johnston one just as he recommends and I like it a lot for the simplicity as long as the ribs have registered holes already..
Cutting my own ribs and trying to accurately place the alignment holes can be easy (constant chord taper) or near impossible for changing chord, taper, swept wings... but a real treat if the holes are registered on LASER cut ribs
Now if I could just learn how NOT to introduce warps with my meager covering skill set or Lately destroying an otherwise beautiful light wing by some wrong method of shrink covering........not sure what I am more agitated with...loss of the TIME to build the beautiful wing...or loss of the (getting more and more expensive) glues
Do remember that a Jig is ONLY as accurate as the underlying FLAT building surface
Side thought...recently got a gift of the TF Nobler ARF and while the covering is suspect the basic wing seems to me real well done and warp free...
BUT I have to only imagine at what speed a 0.10c per hour worker has to complete one of these wings ---and what all sorts of jigs are used.... actually searched You Tube trying to find a china shop wing building video...no luck
Not trying to say the wing is perfect ---as I think we agree some of the glues used are suspect ...but this particular wing is light, warp free, and feels plenty strong in twist, and bow torquing I did... even before trying to iron out the wrinkles and tightening the china kote