G-code Dialects

MapleCAM supports multiple G-code dialects to match different CNC controllers.

Supported Dialects

GRBL

The most common controller for hobby CNC machines. Used by Shapeoko, X-Carve, OpenBuilds, 3018 machines, and many others.

Key characteristics:

Spindle control via M3 S{speed} / M5
Feed rate set with F{rate} on motion commands
Arc commands G2/G3 with I/J offsets
No subroutines or canned cycles

LinuxCNC

An open-source CNC controller running on Linux PCs. Common in more advanced hobby and semi-professional setups.

Key characteristics:

Full G-code implementation including canned cycles
Spindle control via M3 S{speed} / M5
Supports tool change (M6 T{n})
Comment syntax: ; comment or ( comment )

Dialect Differences

Feature	GRBL	LinuxCNC
Comment style	`; comment`	`; comment` or `( comment )`
Arc format	`I/J` incremental	`I/J` incremental
Tool change	Not supported	`M6 T{n}`
Spindle control	`M3`/`M5`	`M3`/`M5`

Choosing a Dialect

Select the dialect in your machine configuration. If you're unsure, GRBL is the safe default — it works with the majority of hobby CNC controllers.