I use fibreglass or carbon arrow shafts for all my pushrods..

i don't muck about.

Orangeman, Check everything and make sure your CG isn't to far aft. Also make sure that you're not having the elevators flutter... I'd be more inclined to re set the servo arm so you have 100 atv and a short arm. This will increase the resolution of the servo and make it more powerful by mechanical advantage.