this shaft in addition the drive belt 28 is looped around a drive pulley not shown which is connected to a shaft 31 mounted in the sewing machine shaft 31 has mounted to it an eccentric 32 cooperating with a bearing 33 which is mounted to the proximal end 34 of the adjustable length drive lever 35 the drive lever 35 has a lever arm 36 attached between the proximal end 34 and the distal end 37 the length of the drive lever 35 may be adjusted by means of the adjusting nut 38 which when loosened will allow the lever arm 36 to be rotated and adjusted for length once the arm 36 is of the correct length the adjusting nut will be tightened against the proximal end fitting 34 to maintain the arm in its desired length the drive lever 35 connects at its distal end 37 with a slotted actuator arm 39 which is in turn fixed to oscillating shaft 24 by means of the adjusting clamp 41 not only is the drive lever 35 adjustable on length but it may also be positioned within slot 42 of actuator arm 39 to give a range of adjustment which may be necessary to give the proper oscillating arc to shaft 24 the oscillating shaft 24 and the rotating.