The Barreto 3107C Chipper utilizes a series of load-sensing valves to optimize material feed. As the load on the feed system increases, or as the chipper flywheel slows, the feed rate will automatically slow or stop to allow the flywheel to maintain maximum RPM. The feed wheel and motor are mounted to a tensioned pivot-arm system. The arms pivot on heavy-duty composite bushings instead of the plastic wear slides used by machines of similar size.