ScottW514
a3e83c4fd5
Rule 15 in the stream harness holds both halves of the minimum (grblHAL-glowforge f7e8c17, pinned here): no emitted burst falls below laser_pulse_min_ticks, excepting one clipped by fire going off mid-burst, and the levels too faint to fill a window still render their exact average density. Checked against a run at minimum 1 so it cannot pass vacuously - level 2 goes from 444 bursts of one tick to 147 of three at the same density, and levels already above the minimum are unchanged. Four bench ladders settle the base period at 20. The same six rungs marked in all of them, and the matched pairs across periods separate the variables: at identical pulse length, halving the density killed the mark; at identical density, varying the pulse 3x changed nothing. Feed does not move it either - 10 percent at F100 carries 44 percent more energy per mm than 20 percent at F300, which marks, and still left nothing. The low-end marking limit is average power, not dose per length and not pulse length. The F100 trace separates two failures that look alike on the material: seven current segments for eight rungs, anchored by a flat saturated final segment that can only be full density, put 5 percent at no discharge at all and 10 percent at a full 15 seconds of current with no mark. Only the first is ours, and the minimum pulse is the answer to it. Also recorded: the factory's Precision Power 1 runs a 19.53 percent FIRE duty cycle at full PWM duty, and its 1-100 scale maps onto density 18.9-79.5 percent, so its 1 percent is the bottom of the useful band rather than 1 percent of the range. Under the density model $35 and $36 are that same control - a density floor and ceiling - which makes the user-facing scale a settings choice rather than new code.
OpenGlow/ForgeFIRM Firmware for Glowforge
Open-source firmware for Glowforge brand CNC lasers. ForgeFIRM replaces the cloud-dependent factory software on the stock control board — no hardware modification — and gives the machine a local controller, a local web control panel, and a standard Grbl interface.
- Latest Release
- Installation Instructions
- Build Instructions
- Connecting LightBurn
- How motion and the laser are driven
- How cooling and airflow work
- The cameras and the video stream
- How the laser safing works
- How a release is accepted
- Community Support
What it does
Two controller modes, selected in the web panel and switchable while the machine is idle:
- GRBL mode — grblHAL runs on the machine and speaks Grbl 1.1 over TCP port 23, so LightBurn, UGS, and cncjs drive the laser directly. Motion runs on the board's own hardware step engine (SDMA + EPIT), fed live by the planner. M3/M4 dynamic laser power, coolant-flow verification, over-temp holds, and an operator button press to arm the laser for each job.
- Cloud mode — the machine presents itself as a stock Glowforge to the Glowforge web service, so the phone and web apps work as they always did. Optional, and off by default. GRBL mode jogs and cuts without it; the one GRBL-mode function that still reaches the Glowforge service is camera-referenced homing (below), until limit-switch homing lands.
Around both modes:
- A web control panel on port 8080: machine status and position, coolant and fan telemetry, safety-switch states, camera view, machine settings, hardware diagnostics, firmware updates, and boot-slot management.
- Camera-referenced homing:
$Hfrom any sender runs the factory-style camera homing cycle through the Glowforge service (a Glowforge account and a live service session are required for$H; everything else in GRBL mode runs without them), and the machine records where it is. - Cameras only capture with the lid closed. The lid camera faces the room once the lid is raised, so ForgeFIRM refuses every capture — live view, snapshot, and anything the Glowforge service asks for in cloud mode — until the enclosure is shut, and stops a running stream the moment the lid opens. See the cameras and the video stream.
Hardware
The control board is common to Glowforge Basic, Plus, and Pro. The 5 MP (OV5648) camera modules are fully supported and hardware-validated. The 8 MP (OV8856) modules found in "HD" units have a complete capture path — the kernel patches, device tree and sensor-aware capture profile they need are all in the build — but it has never run on an 8 MP machine, so treat it as untested; see the camera note in kas/README.md.
Safety
These machines contain a CO₂ laser: it burns, blinds, and starts fires. Never defeat the lid switches or interlock. Never leave a running job unattended — keep a fire extinguisher within reach. Read Before you cut — safety before your first job, and the Regulatory and legal section before installing. How the laser safing works describes the hardware safety chain and the software gates ForgeFIRM stacks on it.
A very important warning: this is experimental software. Use of this software could seriously maim or kill you or others, and voids your warranty. It is not affiliated with or endorsed by Glowforge. Use it at your own risk.