A power tool includes: a housing having a handle configured to be grasped by a user; a motor supported by the housing and defining a motor axis; a driving gear rotated by the motor about the motor axis; a driven gear defining a rotation axis that is parallel to the motor axis, the driven gear engaging the driving gear to be rotated by the driving gear about the rotation axis; a crankshaft coupled to and rotatable with the driven gear; a counterweight having a first yoke coupled to the driven gear to translate rotation of the driven gear into reciprocating motion of the counterweight; and a spindle having a second yoke coupled to the crankshaft to translate rotation of the driven gear into reciprocating motion of the spindle, wherein the counterweight and the spindle reciprocate opposite one another.