Ancient CNC Router Revived with Grbl and Arduino Mega

Evan’s hackerspace, i3Detroit, received an old CNC router for a donation, with the small catch that it didn’t work. On the other hand, it featured a rather large cutting surface, and the mechanicals and motors, if not solid, appeared to at least be serviceable. The decision then was made to get the router to an operational condition, with the long term plan to turn it into a plasma cutter.

With this in mind, they went to work troubleshooting and reviving the system. The first controls component addressed was a 110MHz Cyrix 6x86 computer with 16MB of RAM, and while one would immediately think this was the problem, it happily booted… to Windows 95.

The machine controller itself was housed in a similar AT case to the computer, with a non-working power supply. After swapping this out, the components were addressed, including a dev board by Blue Earth Research called the XPLOR 32, with a ROM chip labled “ShopBotControls Ver. 8 0420980000204.” This handles the steppers via SLA7026M drivers, and with a custom adapter board based on this post, the CNC motors could be properly driven with an Arduino Mega running grbl-Mega firmware.

Although there are still a few steps left to do, such as re-stringing the steel cable to make the X-axis move, the machine is largely functional, stepping under grbl/Grbl-Panel control!