Abstract: Mechanism for controlling the rate of travel of a saw as the saw operates and travels upon a radial arm. A housing contains fluid and an axially movable piston and piston rod. A wheel is operably joined to the piston rod and is connected to the piston rod so that the piston rod moves axially as the wheel rotates. A cable is wound upon the wheel and extends from the wheel and is connected to the saw. As the saw is moved upon the radial arm the cable rotates the wheel, and the wheel forces axial movement of the piston rod and the piston. Movement of the piston forces movement of fluid within the housing. The pressure of the fluid controls the rate of axial movement of the piston and the piston rod and controls the rate of rotary movement of the wheel. Thus, the rate of travel of the cable and the rate of travel of the saw are controlled by the rate at which the piston travels as the piston moves fluid within the housing.