A Ready to Go Grbl CNC Controller

Grbl firmware for Arduino boards and the like is a great alternative to parallel port controllers, and setups using this system are both inexpensive and extremely versatile. Often, however, the mounting of such a board with the power control and other goodies are neglected. This can be especially evident if you’re playing with a scrap CD/DVD player’s stepper/sled assembly, meaning you have to cobble together something every time you want to use it.

This project shows how to make a Grbl unit using mostly scrap materials, that’s ready to hook up to whatever you’re experimenting with on a particular day. The build employs a CNC shield and four motor driver modules to push signals from the Arduino Uno to the steppers themselves. Power is supplied by a laptop power brick.

A repurposed PCB that conveniently contains three momentary pushbuttons and a trio of LEDs is used for control, plus resistors, and a transistor was added to the board to keep the LEDs from burning out. These buttons provide input for Grbl’s ABORT, HOLD, AND RESUME functions, while the lights show controller power, motor power, and motor ENABLE status. The modded board is connected to the Arduino/CNC shield with a Dupont-style header, and a main power switch was mounted through a hole drilled into this PCB.

The PCB is mounted to a recycled plastic handle, along with binding post fixtures used for power input. The entire assembly is affixed to a piece of wood, for a portable arrangement that should be great to facilitate future Grbl usage in a variety of situations!