Again inconsistent cutting! Saturday, Nov 6, a job using 1/8" Baltic birch plywood cut through the wood just as I expected. Settings were 95% power, speed 225, two passes. A few minutes later, I ran a second job using the same settings and procedure with a sheet of plywood I had selected from the same larger sheet. (I buy large sheets of plywood and cut them to size for the GF. ) This time the cut was not all the way through. Keeping the material on the bed, I made a single pass to finish the cut. After this I went through the GF cleaning procedure.
This morning, I ran another job with the same settings, material, and procedure. Once again the cut was not through the material. Again I made a single pass to finish getting through the wood. This time the wood was not cut through. I am not talking about one or two places where there were voids, etc., in the wood. It was all over the sheet.
What is the cause of this inconsistency? This sort of thing should not be happening.
Glowforge support will probably ask you to print the Gift of Good Measure on Proofgrade material with Proofgrade settings to diagnose the performance of your machine. They cannot and do not offer support for materials from other suppliers.
Plywood, even good quality BB, is inconsistent by nature unless specifically engineered and manufactured for laser cutting. Just because it’s “the same sheet same material” doesn’t make it consistent (unlike most plastics or MDFs which are homogenous)
If the GOGM or other PG materials cut as expected then it’s your ply. It’s sucky and kinda tricky but is what it is.
get a very bright light and shine it through the plywood. if you see really dark spots, likely the laser will not cut that, as it is some kind of filler for knot holes in the core. Depending of course on how it is made, to start with.
some folks have had to work around “bad” spots on panels they have cut down from larger sheets. the core material can vary widely I have found.
Since this problem is being seen on materials that were purchased from another company, we can’t offer support for prints that don’t come out as expected. Materials may vary widely from piece to piece, even if they’re created by the same manufacturer. I suggest posting for advice in the Beyond the Manual section of our community. Note that the advice in this section is unsupported and is not reviewed by Glowforge.
Should this happen with a print on Proofgrade materials, please let us know and we’ll help you right away!