My team also noticed this problem and changed our launching mechanism. Videos of our new and improved prototype shooter can be found at. We test fired the new launching mechanism heavily and did not notice wear as much on the balls with specially fitted wheels.
http://robotics.hhs.fuhsd.org/downloads/Ballshooter.avi and
http://robotics.hhs.fuhsd.org/downlo...llshooter2.avi --3mb symmetrical connection