piper chuck,
I think that's what he meant when he says "castoring tailwheel" in the first post. I added landing gear to a small SPAD plane and used a castoring tailwheel. It was one ground looping plane on takeoffs. There wasn't enough rudder area to steer the plane before it ground looped. Ended up having to hook up the tailwheel to the rudder servo for control. Having enough rudder area is a requirement for good ground handling and no steerable tailwheel.

Jesse