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CNC Router Electronics Upgrade

I will be testing a new electronics package for my CNC router. I’ve had these components for some time now but haven’t prioritized setting them up until now.

Back when I first designed my CNC router, Leadshine drivers were significantly more expensive than the Gecko G540 that I ended up using. They have since become an attractive option, so I have been wanting to try them out. I am also interested in testing a toroidal power supply, using the Mesa 7i76e again, and seeing how the Raspberry Pi 4 works as the control computer running Linux CNC.

The existing electronics will be left as-is except for the addition of disconnects that will allow easy swapping between the two configurations. 

The existing configuration is this:

  • 7.3A 48 vdc switching power supply
  • Gecko G540 4-axis stepper driver
  • Desktop computer running LinuxCNC
  • Parallel port interface to the G540
  • Tested a Mesa 7i76e ethernet FPGA board in place of the parallel port interface

The new configuration:

  • Toroidal 48 vdc power supply 
  • Leadshine AM882 stepper drivers
  • Raspberry Pi 4 running LinuxCNC
  • Mesa 7i76e FPGA board (with ethernet interface to PC)
  • 24 vdc switching power supply for the 7i76e board and for field power for all the I/O.

The machine itself is not changing (steppers, homing switches, etc.)

I’m also designing an electronics cabinet that will hold all the components for the new configuration.

I started this project by laying out all my components on a table and coming up with a rough layout and footprint. Next, an electronics box was mocked up with some scrap wood to better understand the sizing, layout, and wire routing. 

As a result of this mock-up, I figured out what to do differently and created a solid model of the new design. 

I will build this new design later. For now, I just want to get all of the electronics up and running and work out any other issues that may come up.

I decided to try out the Raspberry Pi 4 as the controller computer since I had one laying around and I see there is now an official LinuxCNC build for it. I also didn’t want to change the configuration of my existing CNC PC, so I can plug it right back in to the G540 if I run into issues getting this new configuration working.

I took notes on the process and documented it in this setup guide for the Raspberry Pi 4 with LinuxCNC and Mesa 7i76e.