On the back of all combines are rectangle boxes called combine straw choppers which contain a spinning drum with 6 to 12 inch rectangle bars called knives. A combine may start shaking itself literally apart from the worn out knives, shaft bearings, rotors, bushings or missing components of combine straw choppers. The shaking from the previously listed damaged components can quickly damage the housing and require expensive replacement parts to repair the straw chopper. Hart’s Machine Service will repair and replace any component as necessary and balance the rotor to stop the shaking. straw chopper Hart’s is the most experienced and only machine service in Northwestern Ohio, Eastern Indiana or Southern Michigan to repair combine straw choppers.