Thanks for the replys.

The CG started right behind the solid balsa leading edge. I removed the landing gear and added lead to the tail to get it about halfway between the leading edge and the spar.

As for it being twitchy. In level flight, the slightest movement of the elevator will cause a fairly violent pitch change (more so down than up ). I thought that may have been due to the forward CG. It is not unflyable, but it is not very much fun to fly.

Yes, the Chipmunk is a great flyer. I changed mine to a built-up horizontal and elevator hoping to save some weight but ended up having to add weight to the tail anyway. Even with a light engine and doing a lot of carving from the motor rails I was not able to overcome that long nose!

thanks,
David

thanks again,

David