Mechanics for Vario R22 1:4

Machining of the main drive pulley on the 1st stage drive train.
The timing belt pulley is a HTD 3M 120 teeth version.
Starting with a drawing and a bare solid heavy pulley, so lot of weight to loose...
The autorotation unit is a Align 700/800 size unit.
Machining was done on a manual milling machine with a calculating measuring system, no CNC.