This machine consists of a pendular parallelogram that is balanced by a pneumatic spring, plus a radial arm. The gas spring and radial arm assembly fixes the motor head and keeps it perpendicular to the working area. The motor is equipped with a quick-change system and is rotated by compressed air that has previously been filtered and lubricated by a unit for that purpose. Taps and shank tooling fit to the motor’s quick-change system by means of tapholders.