Grbl Variants#
There are 3 major families of the Grbl firmware.
Grbl#
Project website: https://github.com/gnea/grbl
The original Grbl firmware targets the 8-bit microcontroller Atmega 328p, the same one found in Arduino Uno boards. It has a few major limitations:
- Only 3 axes are supported - X, Y and Z
- Because of the limited ROM size, not all features can be used at the same time. Each firmware has to choose which subset of the available features to include
- Because of the limited RAM size, the command buffer is quite short, meaning it can slow down for complex toolpaths
Still, despite its limitations, it has enough capabilities to power most hobbyist CNCs and remains one of the most popular choices to this day.
Note: There are a few clones of Grbl that target more powerful CPUs, like the 8-bit Atmega 2560 and some 32-bit chips. They offer faster processing, more features, and larger command buffers.
GrblHAL#
Project website: https://github.com/grblHAL
GrblHAL is a newer version of Grbl, intended for 32-bit microcontrollers. It supports a fourth axis, tool change protocols, has more memory, and has more settings that can be configured.
FluidNC#
Project website: https://github.com/bdring/FluidNC
FluidNC is an even newer rewrite, using modern coding techniques. It contains a web-based user interface that lets you control the machine from a browser directly, without using sender software.