Method of detecting a workpiece jam condition in a fastener tool

A method of calibrating a drive mechanism in a pneumatic tool, the pneumatic tool comprising a motor;

• the drive mechanism connected to the motor and adapted to drive a piston;
• and a cylinder filled with high-pressure gas;
• the piston accommodated in the cylinder and suitable for a reciprocating motion within the cylinder;
• the drive mechanism comprising a blade fixed to the piston configured for striking a workpiece and a gear coupled to the motor;
• wherein the blade has a first side, a second side opposite the first side, a third side positioned between the first side and the second side, a plurality of lugs extending from the first side, and a geometrical feature on the third side;
• the gear being rotatable about an axis that extends from the first side of the blade to the second side of the blade and comprising a plurality of teeth adapted to engage with the plurality of lugs on the blade such that a rotation of the gear is transformed to a linear movement of the blade, wherein the pneumatic tool further comprises a latch adapted to engage the geometrical feature to lock the blade, wherein the pneumatic tool further comprises an electronic device adapted to move the latch to lock the blade, wherein the method comprising comprises the steps of:
• a) sensing an angular position of the gear;
• b) determining if the gear is in a default position and/or the blade is in a default position;
• and
• c) if either the gear or the blade is not in the respective default position, moving the gear and/or the blade to the respective default position.