I am printing boxes. I have printed them using this same file on this same Glowforge since May of 2021 without any problems. To make the most of the wood, they are puzzled together facing various directions. Today, after printing for 4 hours, I realized the parts didn’t fit together. Everything printed as though the file had been stretched on the Y axis.
So I grabbed the acrylic lids for these boxes that I cut yesterday - sure enough. they are all slightly deeper (as if the file file was stretched on the Y axis) than they should be (by 1/16 inch). Width wise (x-axis) they fit just fine.
Which made me realize I had the same problem last month with a different file.
I was engraving some circles that came out as vertical ovals.
But I have cut and engraved other things that did not do this y-axis-stretchy-thing throughout the same time period.
I use the program INK to design the files. I save the files as plain SVG. But the box file, and the lid file was created and uploaded to the Glowforge desktop in May 2021. They have never been a problem until this print job.
This sounds like a physical problem with the movement of the machine, not a design/file problem. Check your belts and wheels. Look for damage, debris, and tension.
I think you nailed it, Dan! A thin piece of plastic had wrapped around one of the rollers and loosened one belt considerably. Quick, easy fix via the video. I just tested it with the Glowforge measurement keychain print, and the circles came out perfectly round. Thank you!!!
Sometimes when I cut acrylic the laser doesn’t go all the way through the bottom protective cover, and leaves a torn edge when I take the cut piece off. I then reposition the leftover acrylic into the cutting area. I think I cut a piece in such a way that a strip of that leftover protective covering got loose in the system. Seems really random and unlikely to happen again.
I put a flashlight by the Glowforge so I can quickly check the rollers before each day’s cutting.