From c08f1ad7e379ff484d1f10240b4cdc666895ff70 Mon Sep 17 00:00:00 2001 From: ScottW514 Date: Sun, 2 Aug 2026 14:53:22 -0400 Subject: [PATCH] docs: LightBurn setup and operating guide (motion-only stage) --- docs/LIGHTBURN.md | 79 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 docs/LIGHTBURN.md diff --git a/docs/LIGHTBURN.md b/docs/LIGHTBURN.md new file mode 100644 index 0000000..6c5459c --- /dev/null +++ b/docs/LIGHTBURN.md @@ -0,0 +1,79 @@ +# LightBurn setup & operation (ForgeFIRM, motion-only stage) + +Status: written 2026-08-02 for the grblHAL-glowforge controller. At this +stage **the laser cannot fire** — the driver forces the hardware laser +latch locked and never emits the laser bit in the pulse stream. A "job" +runs every motion of the design (cuts at cut speed, travels at travel +speed) with the beam off. Live fire is a later milestone, gated on the +standing scope checks (BRINGUP.md). + +## One-time device setup + +Prerequisite: the controller is running on the board (see BRINGUP.md; +`grblHAL_glowforge` on TCP port 23 at 172.16.1.97). + +1. **Laser window → Devices → Create Manually** (skip auto-find; it + scans serial ports). +2. Device type: **grblHAL** if your LightBurn version lists it, + otherwise **GRBL** — both speak the right protocol. +3. Connection: **Ethernet/TCP**. IP address: **172.16.1.97** (LightBurn + uses TCP port 23 for GRBL devices, which is exactly where the + controller listens). +4. Name: e.g. `Glowforge ForgeFIRM`. Work area: **X 495 mm, Y 279 mm**. +5. **Origin**: pick the corner where the head sits after parking at + home — **rear-left as you face the machine** (the top-left dot in + the selector). This is what keeps jobs un-mirrored: machine +X runs + right, +Y runs from the rear rail toward you. +6. **Auto-home on startup: NO.** Homing is not wired yet; `$H` errors. +7. Finish. If a stale device profile already exists, edit its IP + instead of creating a new one. +8. Device Settings (wrench icon): **S-Value Max = 1000** (matches $30). +9. Optional backup: File → Export Devices → saves a `.lbdev` you can + re-import later (the format is not editable text; export is the way + to make one). + +## Job start mode (important on an unhomed machine) + +In the Laser window set **Start From: Current Position**, and set the +**Job Origin** dot to the same corner as the machine origin (top-left +dot). The job then runs into the bed from wherever the head currently +sits — absolute machine zero never matters, which is the forgiving mode +while the machine has no homing switches. + +(`Absolute Coords` also works, but only if the head was parked at the +home corner when the controller started; after any Stop/alarm the +absolute frame is stale until the controller is restarted with the head +re-parked.) + +## Operating basics + +- **Frame** traces the job's bounding box at travel speed — do it + before every Start. There are **no limit switches**: framing is your + crash protection. +- **Start** runs the job. Travels run up to 200 mm/s; anything faster + in a layer is clamped by the controller ($110/$111 = 12000 mm/min). +- **Pause** = grbl feed hold: motion parks within ~0.4 s (0.2 s stream + queue + deceleration); Resume continues exactly. +- **Stop** = soft reset: motion aborts with a controlled deceleration + and grblHAL raises an alarm with **position declared lost** (the + stream queue means up to ~40 mm of in-flight difference). Recovery: + unlock (`$X` in Console or LightBurn's prompt), jog the head clear, + and carry on in Current Position mode. Restart the controller with + the head re-parked if you want a clean absolute frame. +- **Move tab**: jogging (set a sane speed, e.g. 6000 mm/min), Get + Position, distance buttons. +- **Console tab**: raw grbl — `?` status, `$$` settings, `$X` unlock, + `$J=G91X10F1200` jog. + +## A good first job + +1. Draw a rectangle (~100 × 60 mm) with a circle inside. +2. Double-click the layer color bar (bottom): mode **Line**, speed + **50 mm/s** (= 3000 mm/min; check Edit → Settings for your speed + units), power anything (ignored — nothing fires). +3. Park the head where the job's rear-left corner should be (or leave + it at home), **Frame**, watch the perimeter trace, then **Start**. + +Expected behavior: darting travels at up to 200 mm/s, smooth 50 mm/s +tracing of the shapes, silky and near-silent motion (factory currents + +decay mode), and the head finishing per the job's return setting.