Abstract: A precision woodworking saw having a variable speed drive mechanism which drives a saw blade carried on a reciprocating C arm. An electric motor has a drive shaft carrying a split drive pulley which drives a split driven pulley through a V-belt. The driven pulley is mounted on a driven shaft which reciprocates the C arm through an eccentric drive arm. The pulley sections of the split pulleys are movable toward and away from one another to vary the pitch of each pulley and its effective diameter. An adjustment knob can be turned to adjust both pulleys simultaneously to vary the speed ratio between the driven shaft and drive shaft as desired to control the speed at which the saw blade is driven.