Rotary drum chippers are characterized by a parallel-sided rotary drum, it has attached knives running down the side of its axis. Working in sync with the rotating knives are chip breakers. They are set behind the knives at 90 degree angles to the blades. It is among the first commercially available, and still in production today, drum chippers uses mechanisms made of a large steel drum powered by a motor, usually by a belt. The drum is stationary parallel to the hopper and spins towards the output chute. The drum also serves as a feed mechanism, that draws the material through as it chips it. By using a rotary drum chipper machine the logs and small wood are cut into high quality chips with even length and uniform chip thickness.
The size of the rotary drum wood chips can be adjusted with the knives and anvil. It can also be adjusted by inserting a screen with larger or smaller diameter hole in the exhaust opening of the rotary drum chipper. Particles that are too large to pass through the screen are sent around once more and cut against the anvil.
The rotary drum chipper can be manually or automatically fed with single or multiple stage machines. They may also have single or multiple drums or wheels with single or multiple knives.
The rotary drum chipper is designed and used for cutting logs, branches, planks, slab, bamboo, waste veneer, straw, cotton stalks and other non-wood fiber stems They are mainly used by land developers and park workers to clear forest underbrush easily.