ma_mulcahy

I'm building this kit and have discovered that the right wing panel is bowed about 1/8". It's not a twist, it's just bowed a little. I'm pondering leaving it as is and shimming the saddle to ensure that both wings have the same amount of dihedral. Will this be adequate? If the consensus is that I should work out as much of the bow as possible, I'd appreciate suggestions of tried and true methods.

One more thing. This kit calls for washout in the wing, which I don't intend to build in. I've heard it's more trouble than it's worth. I built a PT-40 around 15 years ago, and had no problems with stalls on the bird w/o washout.

Thanks all for your suggestions.

Mike

d_bodary

My Feedback: (85)

On a trainer i doubt a 1/8 inch is going to be noticeable. depending on what type of glue used for instance white glue or yellow wood glue you could always spray it down with water/ammonia 50/50 mix and weight it straight and walk away for a few days. If your lucky the water will loosen the wood and the glue allowing it dry straight. Then when you monokote it will try and twist the wing also.

As far as the washout goes when i built my pt-40 about 9 or 10 years ago i used the washout jigs. But if i ever built another one i would'nt bother.

Hope this helps
Dennis

johnboyrc

That much warp won't affect this trainer enough to worry about. Washout probably won't matter too much, but it's nice knowing you don't have to worry about tip stalling. Mine would sail and float for a long time without dropping a tip. If it were me, I'd put a little in, but not as much as the jigs are setup for. Are you going with the sport diheral or the training dihedral? The training style was too much, wish I had done the sport style. But then again, it was a trainer for me and served it's purpose well.

ma_mulcahy

Thanks for the feedback. I've used CA for all of the construction. I only use white/yellow glue when I am edge gluing sheets because it makes them easier to sand. I am guessing the water/ammonia won't be quite as effective with CA in the joints?

I'm building the sport dihedral rather than trainer dihedral which seemed rather extreme.

Mike

carrellh

Mike,
I built my PT-60 with sport wing and no washout. My dihedral was slightly less than specification because I stopped sanding when everything lined up nicely. My instructor told me to build without the washout. He said it is not needed on this plane. When he flew the maiden, he tested the stall characteristics and said tip stalling would not be an issue.