How do you square a jig on the laser bed with absolute coordinates?
The jig is perfect. Now it has to sit in exactly the spot the file thinks it does. Computer Creationz engraves small targets into the jig, runs the job in LightBurn absolute coordinates, and drives the red dot to each target. Two targets on, the jig is square.
Applies to
- Software
- LightBurn: absolute coordinates + laser position tool
- Machine
- A laser that homes, with a red-dot pointer
- When
- Every time a jig goes back on the bed
Why it matters
Absolute coordinates mean the file position is the bed position. That only helps if the jig is where the file says, and square to the axes.
One target tells you position. Two opposite targets tell you rotation. That’s why he aligns the top left, then checks the bottom right and swings the jig around the first corner.
Target size is a neat detail. Make it about the size of the red dot and, when you’re centered, the dot almost disappears into it. Easy to see when you’re off.
What good looks like
- The red dot lands dead center on every target you drive to
- A pocket corner checks out too
- The jig is pinned or clamped once aligned
- Whole setup done in under a minute
How to apply it
- In the jig design, snap a 1¼ × 1¼ in tool-layer box into each corner, then snap a target into each box so the targets sit uniformly.
- Add a few extra targets along the reference line; they can go anywhere.
- Engrave the targets with the jig. For the job, set LightBurn to absolute coordinates.
- Pick the laser position tool, click the top-left target, and set the jig under the dot.
- Click the bottom-right target. If it’s off, hold the top-left corner and swing the jig until the dot is centered.
- Drive to a middle target and a pocket corner to confirm, then pin the jig down and run the batch.
Exceptions & tradeoffs
Your red dot has to be honest. A side-mounted pointer can shift with focus height, so burn a test mark and compare it to the dot before you trust targets.
This is about the only time Computer Creationz uses absolute coordinates. For one-off jobs, user origin or current position is usually quicker.
Common mistakes
- Aligning to one target and calling it doneAlways check the opposite corner; one point can’t show rotation
- Targets way bigger than the dotSize them close to the dot so a near-miss is obvious
- Running the jig job in current position modeUse absolute coordinates so the file and bed match
- Not pinning the jig downClamp or pin it once aligned; one bump undoes everything
Frequently asked questions
- What are absolute coordinates in LightBurn?A start mode where the job runs at the exact bed position shown in the workspace, measured from the machine’s home. It’s what makes a reusable jig line up.
- How do you line up a jig on a laser bed?Engrave small targets in the jig, then use LightBurn’s laser position tool to drive the red dot to opposite targets. Set one, swing the jig until the other matches, and pin it down.
- How big should laser alignment targets be?About the size of your red dot. Computer Creationz uses 0.0584 in, so a centered dot nearly vanishes into the target.
Target sized to the red dot (0.0584 in) so it nearly disappears when centered — Making laser jigs the easy way! (Setup time is less than 1 minute) ↗ at 04:37.
1¼ in boxes snapped to each corner to place targets uniformly; extra targets on the reference line — Making laser jigs the easy way! (Setup time is less than 1 minute) ↗ at 09:02.
Laser position tool: drive to the top-left target, then the opposite corner — Making laser jigs the easy way! (Setup time is less than 1 minute) ↗ at 14:52.
Hold one corner and swing the jig until the opposite target lines up; pin it down — Making laser jigs the easy way! (Setup time is less than 1 minute) ↗ at 15:52.
Absolute coordinates for templates; setup in under a minute — Making laser jigs the easy way! (Setup time is less than 1 minute) ↗ at 17:33.
The targets, the dot-sized trick and the swing-from-one-corner move are all Computer Creationz’s. The red-dot check is ours. A pointer that lies makes every target lie with it.