Automation of a Sherline lathe with Mach3

Sherline lathe

I have choosen Mach3 to digitalize my Sherline lathe as I did good experiences with this software on my milling machine. I would have preferred LinuxCNC, but, unfortunately, this software does not allow to calibrate a tool in the middle on a machining program (at leasat with the version I used). As I do not have tool changer, I had to create several gcodes files for each tools.

Stepper drivers

I firstly tested a TB6560 CNC Mach3 driver that is a 30$ low cost device. I had several issues with it, such as stepper motors missing steps and, after research on the net, learned that they are using very

TB6560 low cost opto-coupler that have low bandwidth.

I then tested an MX3660 from Leadshine: this device is much more expensive than the TB6560, but it works perfectly. In addition to the stepper driver outputs, it also has several inputs I will use to build an indexing system for machining screws.

Stepper motors

NEMA 23

I'm using 57BYGH56-401A NEMA 23 Stepper Motor Single Shaft. They work without any issue in 800 micro step mode. The only issue is maybe the single shaft: it is not possible tu add a hand wheel. However, it is not a big deal to use: I'm anyway always using Mach3, even for "manual" work.

Up to now, I'm very happy with these stepper motors.

 

Installation

The stepper motors are fixed on the Sherline lathe with the support provided by this manufacturer. They might seem a bit expensive and it is possible to make them, but they are of good quality and it's quick to install them.

I soldered a plug to the stepper motor cables and made a braided cable extension. Connections on the TB6560 are easy to do as everything is documented on the device box itself.

Configuration

Configuration of Mach3 might be a bit tricky.

Start Mach3 with the Mach3Turn icon. When the program is up and running, go on the Config->Port and pin menu, then select the Motor Outputs tab and make sure it looks like the figure below.

Mach3 configuration

Also make sure that pins configured above are not used in another tab such as Input Signals or Output Sifnals.

Tests

After having powered, I check for some "bad smelling", but everything was ok. When I pressed the keyboard arrow, the lathe axes moved without any problem.

I did a first small machining test with a part of aluminum and gcode generated by a Mach3 wizard: everything was fine. The lathe is ready.

Make sure the power supply and the stepper driver are protected before trying to machining as chips could reach internal electronic and destroy the circuits.

 

If you have any question about this project do not hesitate to post them in the forum.

Project