I havn't built a kit in awhile, and despite my best efforts, I got a small amount of twist (1/8") in my left wing half. Is there anyway to remove the twist without disassembling the entire wing half. The twist appears to be in the trailing edge near the wing tip.

A little more info is needed. What kit is it?
And have you built the right wing yet? It could be that there's wash out (or wash in) built into it and it's supposed to be like that.

The Kit is an LT-Kadet 40. I have built the right wing, and there dosn't appear to be the twist that I see in the left wing half. When I match the wing halves, there is a bit of a gap (1/8") at the trailing edge.

Try bracing the root end flat against the table with some heavy weights, then place about a 1/2" block under the LE at the tip with a weight on the TE (again at the tip). Note: this is if the TE is twisted up, if it's down, block up the TE with a weight at the LE.

Let it sit overnight and see how it looks in the AM

I had a warped wing with my LT 49. The trailing edge was the problem. Mine was as hard as a brick. I soaked it in water and amonia and set a weight on top of it. It straighten out fine and in about a week re-warped. Fly it.

You can take this small of a twist out after you cover , cover the wing as normal.
When the the wing is covered and shrunk twist the offending panel in the direction you need remove the twist and reshrink the film = Done.
1/8'' you could just leave in and you most likely not even notice on the LT40 I've seen much worse and they flew Ok.



Den

Minnflier, I tried your method and about 1/16" of the twist is gone. I guess I will have to live with the rest for now. Will try to take out what I can when I cover.

You could also try going from a 1/2" block to a 1" block and letting it sit some more. But a 1/16 twist will probably come out by shrinking the covering.

Have built all my trainer & old timers with a twist in the wing trailing edge up to & 1/2" higher than center section, called wash out. Don`t go the other way, wash in. The outer wing stalls later than the center when at a higher angle of attack with wash out.
>>>>>>>>big max 1935>>>>>>>>

Saturate the whole wing with straight ammonia, set down on something solid like a concrete floor, wieght it down and leave for 3 to 4 days depending on how hot it is.

No problem... for 1/8" of twist, your covering should be able to hold it straight easily.

When you cover, be sure that the covering starts out snug in the diagonal from low corner to low corner on the upper side and raised corner to raised corner on the under -- before shrinking. (Best covering jobs have the covering pretty evenly snug all over, but most people get by without ever accomplishing that.) As you tighten up your covering, hold opposite twist in the wing, a little past what it takes to neutralize the unwanted twist... hold it that way till the covering cools a minute and your wing should be straight.

For an interesting insight on how much you can straighten )or twist) a wing with the covering, check the instructions for a PT-40. (I think you can find them at the Great Planes site.) Its wing is supposed to have 3/4" of washout and it was originally built with none and twisted entirely by the covering. The newer versions are supposed to be built with the twist already glued in, but They've cut the parts so precisely that even if you build in the twist they recommend, almost all of it pops out when you take a wing panel off the building board... so you're still stuck twisting in most of its huge wash-out with the covering!

For what it's worth, I have just completed a PT-40. The washout is buit in by the sheeting and not the covering. Take the wing skeleton, support the Trailing edge of the wing-tips so that the trailing edge at the wing root is 1" off the work surface. Add weight to the wing root so that there is "twist". Sheet the wing with the 1/16 balsa. Viola! Washout-enabled.

gus

I agree with Gus.
I also just completed a PT-40 with washout,using the supplied
jig and sheeting the wing,and I'm sure it will work straighting out your wing.

I appreciate all your suggestions. I will see what I can do with the covering. Havn'et coverd a model in along time, kinda nervous about that part of the project. But I think I can muddle through especially with MinnFlyer instructions.

Finding this site has been a god send.

It's good to hear that the directions are working for locking in the twist in the new kits. I don't know if maybe the one I did was an early kit or what (it's been a while since my last PT-40), but everything went together tight as a drum and as soon as it was lifted from the table, most of the wash out ...uhhh... washed out!