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Building Tips and technical articles. => Building techniques => Topic started by: Chris Belcher on November 29, 2016, 03:54:17 PM
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OK...don't know how I did it but I managed to build a pretty decent warp into a Legacy 40 wing ON A JIG! This is the Brodak kit on the Brodak jig where you build half at a time and join together. First half is the one with the warp. It's a good 3/16" wash at the tip. Leading edge looks and measures straight but the trialing edge...well...it's noticeable...and measurable. SO...I wonder if I should try to get a set of ribs and start over or is it possible to "remove" the trailing edge sheeting as I am pretty sure that's where the warp was induced. I remember pushing down pretty hard to get the sheeting to stick and must have pushed a curve into the wing. The outboard (second) half is nice and straight but the inboard...it's ugly. Any chance of steaming a built in warp out?...or using covering to try to pull it out. I kinda already know the answer to both of these would be a compromise. I really want to just punt and redo the inboard wing...just need the ribs.
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Chris,
Do you build with CA?
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Yup
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If it is not covered and all the sheeting is not on, you might do like I did with my B25 build. Of course it wasn't built on a jig either. I just twisted the wing until I heard it cracking. Once it stayed where I wanted it to be straight I then hit all the joints with Elmer's Glue All. Kept checking as I put the leading edge sheeting on. Now waiting for clear coat and is still straight.
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Seems to me like you don't have anything to lose by getting after the current wing with some harsh treatment. Even a bare wing would respond to hot water on a towel. I'd give it a go.
Try clipping a lengthwise folded hand towel on each side of the TE and pour boiling water on them. Give it 10 minutes and start bending and blocking it into submission. You'll probably have to over-bend it to get it straight. Once it is straight, I'd give it a week or two in the free state to see if it stays put. At least it'd give you something to do while waiting for a new set of ribs (or complete wing kit) to arrive.
Alternatively, you might experiment with applying CA de-bonder onto the joints and see if that might work. If you can get some nitro methane, that's supposed to work as de-bonder. That, or bash the crap out of it with a LiPo battery. LL~ Steve
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So I pulled the trailing edge sheeting off...no relief. Pulled the trailing edge off...no relief. The warp was built into the leading edge when I put on the sheeting. How does one go about getting a set of ribs for a Legacy 40? I'll just rebuild the inboard panel and join to the good outboard.
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Contact Brodak.
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Doc---Advice I was going to offer also
Brodak can probably provide a complete rib set
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Found it: Legacy 40 Wing Rib set, SKU#CLB-85RS . $29.00 + shipping.
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THANK YOU SIR!!!
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I have often found that a wing warp is assured whenever you have to force parts together, like spars onto wing rib slots, etc. Kits are usually cut to exact fits, but sometimes you need to be careful about this.
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Yup. If you're forcing it, you're building in a warp. Sometimes you can peel the sheeting off and re-glue, or even just take the shear webs out and re-glue. On the other hand, a re-do from scratch has the advantage that you can put the warped part on the floor and stomp on it until you feel better.
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Yup. If you're forcing it, you're building in a warp. Sometimes you can peel the sheeting off and re-glue, or even just take the shear webs out and re-glue. On the other hand, a re-do from scratch has the advantage that you can put the warped part on the floor and stomp on it until you feel better.
Lmao!!!
Sent from my SAMSUNG-SM-G891A using Tapatalk
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Hope you haven't destroyed the wing yet. I have planes that had warps I couldn't see or find. One in particular was an ARF Flite Streak. Had several people look at it and couldn't see or measure a warp. It wasn't tip weight either. The old Coke can cured the problem of the plane not flying level. Even before the Coke can trim tab it never came in at me or got light on the lines. Put you wing in a profile to fly for fun and use a trim tab to level the wing.
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A wing tab, or "wart", is not a reliable fix for a warp. The tab and the warp "fight" each other, with strange things happening! The very best solution is to remove the warp and have it done right.
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A wing tab, or "wart", is not a reliable fix for a warp. The tab and the warp "fight" each other, with strange things happening! The very best solution is to remove the warp and have it done right.
Yup. Tabs are great if the alternative is to chuck the plane. If you're still at the bare wing stage -- fix the warp!
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Ordered a rib set from Brodak...stomped the warp ;D
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Ordered a rib set from Brodak...stomped the warp ;D
Go slow. I have the big Legacy kit, and when I went to put in the spar I found that the spar notches and LE notches (or perhaps the wing jig holes) weren't all in alignment. I ended up carving each notch individually to get the spar to slip in correctly. Had I just thumped the thing together assuming that the kit was right I'd have had a horribly warped-up wing on my hands.
The full story starts here (http://stunthanger.com/smf/open-forum/legacy-build/msg390111/#msg390111).
(http://stunthanger.com/smf/open-forum/legacy-build/?action=dlattach;attach=157884;image)