If you want to be able to control a 4-axis CNC with grbl and Grbl Controller you will need an Arduino Mega 2560. Be aware that I’ve only added support for it in Grbl Controller, I haven’t actually hooked up a 4th axis yet, other users have done so, however.
NOTE: grbl is meant to work on the Uno or equivalent – Don’t spend money unnecessarily on the Mega if you don’t need 4-axis!
I’ve moved old info on programming hex files here and updated this page to focus more on Grbl Controller and grbl support on Mega 2560.
Our friend Letartare has created some new versions of 4-axis grbl based on various hardware and grbl versions on github. What is important to note is that you no longer have to compile and upload with the AVR tools, instead, he has told the Arduino IDE to compile and upload grbl, which makes working with the files much easier for everyone.
Before you begin, I strongly recommend that you are able to build and run a basic Arduino sketch like Blink on the 2560 – this makes sure you have all the drivers installed properly.
Once you have that, do the following (these instructions are on the project’s readme on github):
- Clone the repository: git clone https://github.com/LETARTARE/Grbl_with_Arduino
- Copy the desired build, which is a subfolder, i.e. Grbl84Mega2560, into your Arduino 1.0.5x libraries folder.
- Restart Arduino IDE if open
- Open the example ino: File | Examples | Grbl84Mega2560 | GRBLtoMega
- Compiled and Upload
- Connect with Grbl Controller at 57600 baud (or choose correct rate based on the particular build)
- You should see the appropriate greeting from grbl
Windows Grbl Controller using A-axis