Indexing tool for threading with Mach3 on Sherline lathe

Sherline lathe

This project is still a work in progress:

  • Wheel is finished
  • Support is finished
  • Power supply is being tested
  • Sensor is being tested
  • Mach3 configuration is being tested

Machining thread with a Sherline lathe and Mach3 require measuring the angle position of the axis.The angular position sensor is constituted by a perforated disk and an optical beam. Mach3 synchronize the rotation speed and the Z axis to machine threads.


I'm using a PM-24P PNP open-collector transistor optical sensor. The power supply of the sensor is maximum 24V and the power supply of my MX3660 stepper driver is about 28V: it is therefore necessary to add a small circuit to generate the adequate voltage.

Indexing wheel being machined

Indexing wheel

The indexing wheel is machined in aluminum The accuracy is not critical, but avoid asymmetry as id could generate vibrations.

The indexing wheel has been machined on my Sherline lathe, and the necessary gcode generated by the Mach3 wizzard.

Support for sensor

Support with optical sensor

The support for the optical sensor has been printed in PLA on my 3D printer. It is possible to machine it on a milling machine, but PLA is sufficient for my needs.

Wheel finished

The 3D printer STL file is attached below.




Power supply for sensor

The power supply for the sensor is made of an LM7812 and two capacitors. A resistor has been added as pull-down for the input of the MX3660.


The MX3660 really requires a 12V signal: I tested with 5V, as I have 7805 in stock, but it does not work. You really have to use a 12V power regulator.

Mach3 configuration

Will be done soon smiley