The fourth axis of the engraving machine (A-axis, rotary axis, CNC indexing head) with harmonic reduction gearbox 
Model No.: 17-50-100A(B) 
Chuck Model No.: K11-100MM three-jaw centring chuck (K12-100 is four-jaw centring chuck) 
Centre height: 65MM 
Total height: 105MM 
Angle: 0.036 degrees/step (50:1) 
Reduction gearbox Model No.: 17-50 or 17-100 100 
Reduction ratio: 50:1 (100:1) optional 
Base material: aluminium alloy 
Stepping motor: 57MM 3A 2-phase 4-wire stepping motor