Thanks for your help,
Just been over it, all tail controls smooth and correct. gear def. not slipping, hub's not rotating(this has happened before).
Yes this does only happen when i give sharp input on rudder.
I did however notice that i was only getting approx 30 deg right and 45-50 deg left on the servo, allowing for the fact it " holds to each side when stationary". So I hooked the servo direct to the rec. and it centered to the left. Repositioned arm so now i get 45deg each way with gyro hooked up. maybe i wasnt getting enough travel to compensate?
It could be a drop in tail rpm but cant detect a change in the head speed when it happens. I do know it loses power as it gets hotter. Having a scale body doesnt help i suppose.
Thanks again
JA