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.

A reciprocating power tool includes a housing; a power assembly including an electric motor; a transmission assembly connected to the power assembly; a reciprocating assembly connected to the transmission assembly, performing a reciprocating motion, and mountable with a working accessory for an operation; and a balancing component for balancing a motion of the reciprocating assembly. A maximum distance the centroid of the reciprocating assembly moves is a first distance L1; a maximum distance the centroid of the balancing component moves is a second distance L2; the mass of the reciprocating assembly is a first mass M1, and the mass of the balancing component is a second mass M2; the ratio of a product M2.Math.L2 of the second mass M2 and the second distance L2 to a product M1.Math.L1 of the first mass M1 and the first distance L1 is greater than 1.05.

A saw including a spindle assembly having a frame and a spindle that reciprocates between a back-dead-center (BDC) to a front-dead-center (FDC) along a spindle axis. The spindle includes a blade connection that defines a connection axis. The saw includes an orbital plate, an eccentric drive member, and a follower engaged with a cam surface on the orbital plate to pivot the frame about a pivot axis. The cam surface includes a high frequency segment occupying less than 180 degrees of a circumference of the cam surface. A displacement of the connection axis relative in a direction perpendicular to the spindle axis is zero at the FDC. A total displacement of the connection axis in the direction perpendicular to the spindle axis occurs during a forward stroke and a reverse stroke. The high frequency segment is configured to displace the connection axis between 80% to 100% of the total displacement.

A reciprocating power tool includes a transmission that converts rotational force from a motor to linear forces output by a reciprocating device and a counterbalancing device. The transmission is a parallel axis transmission including a first gear portion and a second gear portion formed on a gear shaft, with the first gear portion and the second gear portion rotating together about a first rotational axis. The first gear portion rotates a first output gear and the second gear portion rotates a second output gear about a second rotational axis that is parallel to and offset from the first rotational axis. The first output gear drives the reciprocating device and the second output gear drives the counterbalancing device. The reciprocating device reciprocates linearly and the counterbalancing devices performs a linear reciprocating movement that is opposite that of the reciprocating device to counterbalance forces generated by operation of the reciprocating device.