Among other applications, you can use this to make zero-kerf photo jigsaw puzzles.
Beginners: If you've never made a laser-cut jigsaw puzzle before, learn the easy way first. There are a lot of tutorials on YouTube.
Experienced puzzle makers: Eliminating kerf is straightforward but requires more effort. Larger puzzles are expensive because you need multiple pages.
Any comments or questions may be posted in the Glowforge forum.
This quick video shows the essence of the precision cutting technique, which can often achive “naked-eye perfect” alignment. (This is also the companion video for Part 1 of the tutorial.)
The short answer: Just barely … usually … depending on the use case.
Jigsaw puzzle pieces should be relatively aligned within 0.2mm (depending on photo, resolution, piece size, audience). This method usually gets me 0.2mm accuracy.
Puzzles cut from a single page appear perfect, because if you keep adjacent pieces close together, the relative error cancels out. You mainly have to worry about alignment between separate pages. You can mitigate that problem by taking care in how the puzzle is divided; see Part 4.
Because in laser cutting, the kerf is always wider on top, narrower on the bottom. For jigsaw puzzles, if you want the kerf reduced or eliminated on the front face, you need to cut it upside-down.
It compensates for these sources of error, any of which can be greater than our target accuracy of 0.2mm:
The sled is designed to directly align the printed image’s boundaries with Glowforge’s coordinate system, without the intermediate step of going through the (irrelevant) real-world coordinate system. The sled is disposable and generally single-use because of (4).