Why this matters
Understand the coordinate chain that lets a GRBL-style machine know where it is and prevents jobs from being planned outside known travel.
How it works
- Homing establishes a known machine position by finding configured limit/home switches.
- Soft Limits rely on known machine coordinates and configured maximum travel to reject moves outside the workspace.
- GRBL ALARM:2 commonly means a commanded motion would leave the known work area, but the root cause may be job placement, origin choice, rotary configuration or firmware/workspace configuration.
Practical workflow
- Confirm the machine physically has homing switches before enabling automatic homing.
- Home the machine and compare reported Move coordinates with the real head location.
- Verify maximum X/Y travel and workspace size.
- Test Absolute Coordinates with a small safe frame.
- Treat a Soft Limit alarm as diagnostic information and find the cause before disabling protection.
What to watch for
- Using
$Xor disabling limits can clear symptoms without fixing lost coordinates or bad configuration.
