Homing¶

The machine has no limit or home switches as it ships. This page tells you how the machine finds its origin with the cameras, what the machine does without one, and what each homing setting means.

The mechanism, the homing runner and its handover, is in Homing internals.

The homing method is a setting¶

homing_mode, on the panel's Machine tab, selects what $H does. The controller re-reads it on every $H.

Camera-referenced homing¶

$H from any sender runs the factory-style camera homing cycle through the Glowforge service. The service takes a lid image, moves the head, takes another, and computes where the head is; the machine moves to the home corner. The service's lens hunt is answered as done without moving the lens; after the session the lens takes its own reference on the hall sensor's edge, Z is set to the focal point's height above the tray at that edge, the number Commissioning measured, and the lens then moves to the park height, lens_park_z_mm on the Machine tab (default 3 mm), so a home ends focused about 3 mm above the bed.

• It needs a Glowforge account and a live service session. This is the one part of GRBL mode that reaches the Glowforge service; everything else in GRBL mode runs without it. The cycle uses the machine's own credentials (the factory fuse identity, or the overrides on the GF Cloud tab; see Cloud mode) and names its software as ForgeFIRM.
• It needs the lid closed. The camera steps need it, and the move to the home corner is an ordinary motion action: refused with the lid open, and stopped if the lid opens partway through. The lens reference after the session does not need the lid.
• It takes about a minute. A full cycle runs in 50 to 65 s. While it runs, $H suspends the stream engine, runs the session, and hands the machine back; your sender keeps getting status reports.
• It can fail or time out. gfcloud_home_timeout_s (default 300 s) is the budget for the whole session (sign-in, camera uploads, hunt, and corner moves). Past it, or on a failure, the controller alarms (ALARM:18) like a failed core homing cycle. A soft reset (^X) aborts the session.
• A quiet service is not a homing. The cycle counts as complete only when the accelerometer in the print head witnessed real motion during the session. A service that goes quiet without moving the head is a failure.

After a successful home the position is anchored and the panel shows it normally. The home corner is the back-left corner of the bed, and the workspace is all-positive from there (+Y runs toward the front of the machine; Z counts positive upward). gfcloud_home_x/y on the Machine tab set the machine X and Y the head is at after a completed homing (defaults 0 / 0): leave them blank until a measurement says otherwise. Z after a home is lens_park_z_mm, the focus height the lens parks at; the focus card measured where the hall edge sits in that frame. To calibrate: home, jog to a known reference, and enter the measured offsets.

Do not let a sender home automatically on connect: LightBurn's Auto-home on startup stays off, and you run $H deliberately from its Console tab when you want a true machine origin (LightBurn).

Running unhomed¶

The machine cuts fine unhomed. Without a reference, coordinates are relative to wherever the head happened to be, so the panel shows position in red to say so, and your sender should use a job-start mode that does not depend on machine coordinates: in LightBurn, Start From: Current Position (LightBurn, Job start mode).

Anything that invalidates position, an underrun or a stream fault, drops the anchor deliberately, so a stale origin cannot be reused. Re-home before you trust coordinates again.

Homing in cloud mode¶

Cloud homing is automatic and camera-based; the service runs it when the machine connects and after prints. The lens hunt references Z against the hall sensor. Connecting zeroes the machine's counters at the head's current position, so GRBL-mode coordinates do not survive a switch to cloud mode and back: re-home after switching (Modes, Cloud mode).