Cutting fresh wood into small pieces, rather than into chips, may help avoid fermentations occurring in storage. A prototype was developed for reducing tree trunks into pieces through an innovative cutting mechanism that performs a gradual and oblique cut. The device consists of a large auger in which a knife, with a triangular section, is inserted on the outer edge of the helicoid, protruding 70 mm from the flight. The trunks, fed perpendicularly into the machine, are pushed along the axis and slices are cut off against a fixed counter blade having a sharp edge. The main frame of the machine is the cylinder enclosing the auger, it is closed at one end where a heavy flywheel is inserted to deliver the energy coming from the tractor's PTO. The pieces exit through the opposite end. The auger has a 700 mm diameter and a 300 mm pitch spacing. The logs are pushed into the machine by counter-rotating rollers placed in the feed funnel. Tests were carried out to establish operative performance and power requirements of the machine. The cutting method requires less power compared to wood chipping machines. Work capacity is grater when producing slices instead of chips and the system produces less noise and fewer vibrations in the machine. The auger reaches a constant velocity of 200 RPM, cutting fresh wood of different species easily, up to a maximum trunk diameter of 20 cm. The length of the slices of wood can range from 4 to 19 cm.
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