I have a couple of (or had a couple - lost one this season) of PT-40s, good flyers overall, I hope you did not build the beginner wing, it has way too much dihedral.

It sounds to me like you did build the big dihedral wing, with that wing there is a tendancy to have the wind pick it up and flip it at slow speeds. You may also be pulling up too hard on rotation and stalling it. The first thing I would do is ease off on the elevator during take off, and step on the left rudder a bit more, that should null out the right yaw. I would also try to get a bit more speed up when you are taking off, that should help with the problem as well.

Good luck!

Manks