Supporters of the chain or rope lift the saw unit convince us that weakness is a bronze head screw nut, which over time can also wear. But in the process of choosing between replacing end-of-date gear motor or a replacement bronze nuts economically more expedient to replace the nut, rather than expensive, imported in bulk of the motor-reducer, which is 10 times more expensive. 4. Pulleys, which moves the saw tape: There should be no less than 500mm diameter, all-metal barrel with no spokes, as in the spokes of cast-iron pulleys in the process occur cracks, which lead to its destruction. In order to facilitate weight pulley allowed circular holes located around the perimeter of 4 to 6 pieces with a diameter up to 100 mm.Obrezinennye (futurirovannye) pulleys shall have the following disadvantages, which reduce to zero all advantages associated with soft rubber swing Saw belt: buildup of sawdust on rubber surface, and as a consequence of the emergence of a mixture of sawdust cones with the resin, the impossibility of using scrapers that clean the Saw pulleys, as with sawdust washed rubber layer can not use cutting fluids based on diesel and kerosene, as they corrode the rubber coating. You have to use water in summer with detergent, which adds moisture timber, and in the winter to use antifreeze or antifreeze liquid for washing a car windshield, which is certainly expensive. Finally, even under ideal conditions of the rubber coating is sufficient only for a few months and then be replaced.