This is a motorised 4th axis for a CNC machine. It consist of the dividing head with motor and driving belt as well as the tail stock to keep the workpiece aligned. The included chuck is a 4-jaw K12 chuck and an additional set of jaws are included to clamp a cylinder on the inner diameter instead of the outer diameter. The height from the bed of the CNC machine to the centre of the 4th axis is 65mm.

The motor is connected via a closed loop timing belt to the chuck with a 6:1 gear reduction ratio. This improves the resolution to 0.6 Degree/step. The motor is a NEMA 23 x 76mm bipolar stepper motor with a current rating of 2.8A. This allows the 4th axis to be operated with an increased resolution of 1200 steps/revolution.

Specifications:

Height of 4th Axis: 65mm from floor to centre line
Chuck: K12 100mm 4-jaw chuck
Motor: NEMA 23 x 76mm Bipolar Stepper Motor
Motor Current: 2.8A
Motor Coil Resistance: 1.3 Ohm
Motor Wire Coding:

A+: Green
A- : Red
B+: Blue
B- : Yellow

4th Axis resolution: 0.3 Degree/Step (1200 steps per revolution)

4th Axis for CNC machine, 100mm Chuck