The Centerless System rotates the valve stem on it's own centerline. Precision drive rollers rotate the valve stem and a pneumatic low friction steady rest support the valve stem similar to a precision balancing machine, resulting in extremely accurate valve stem to valve seat run out less than .0002" (.005mm) TIR. The Rottler Centerless System allows a wide range of valve stem diameters to be ground without changing any collets or chucks.
Stroking Handwheel - The new design stroking handwheel moves the valve back and forth over the grinding wheel. When operator's hand is removed from the stroking handwheel, the stroking system remains in position until the operator moves the handwheel again.