Gang Mill

a machine for lengthwise cutting of logs, beams, and other items. The first references to mechanized sawing in Russia, which was done with water-powered and wind-powered sawmills, date to the end of the 17th century. Gang mills driven by a steam engine were constructed in the 1820’s.

The cutting tool of a gang mill is a saw or group of saws mounted on a frame, which is set in reciprocating motion by a crank gear. The log to be cut is propelled into the saws by feed rollers. A distinction is made between gang mills with a rectilinear and closed curvilinear motion of the frame. In gang mills of the first type the maximum diameter of the materials to be cut is determined by the width and stroke of the frame (the efficiency of sawdust removal depends on the stroke); in mills of the second type the diameter is limited by the size of the frame itself. Gang mills are designed with vertical and horizontal saws, with continuous or periodic feed, and with one or two frames.

The main parameters of gang mills are the clearance between the side supports of the frame, which determines the maximum diameter of logs that can be cut; the stroke of the frame; the speed of rotation of the crankshaft; the log feed per rotation of the crankshaft; and the power of the drive. In the USSR, gang mills are built with a clearance of 350–1,100 mm, a frame stroke of 200–700 mm, a frame speed of 300–600 strokes per minute, a feed rate of up to 60 mm per revolution, and a main drive power of up to 135 kilowatts.