U need a a maxim 200w servo system, with 750w , u make an rocket launcher .
But if u use a servo u need to make a rigid build , because they are high acceleration and deceleration , and the build will vibrate if u dont make it stiff enough , and u need a gt 3 or htd 3 for servo , with steel insert if u want to be able to use the benefits of a servo , with a gt 2 belt , i dont think its stiff enough for a servo system .