Well, I guess I already learned it, by “well, don’t do that!” But would like some clarification on the GlowForge autofocus. I had the crumb tray in, and put a bamboo cutting board in that’s about 3/4” thick. I checked and it cleared the laser head and then some. Send the job, a 8 min logo, and wow it’s blurry. Canceled the job and sort of ruined my board. Sanded it down, pulled the crumb tray added spacers under the board (just less than 1” of spacer) and ran the same job. Perfect engrave. Hmmmm. How does autofocus work? Seems like it should have warned me I was too close to the head and made me over ride/cancel.
Now I am nervous about how thick something can be, I sort of ruined someone’s cutting board. I will sand it some more and see how it looks.
It is. But it is only one spot autofocus, not continuous autofocus which is still in the “to do” category. The range of autofocus is 0-0.433 inches from the top of the tray. Clearly 3/4" is outside the range and the UI won’t let you set it to that height. If you leave the focus height unset or use Proofgrade settings it does the autofocus thing from one spot.
As for a warning when your material is too thick, seems like a good suggestion for the hopper, but my speculation would be that it will be in there a good long while.
You know, a couple of things surprised me about this. One is that the air assist didn’t hit your material. I’m pretty sure there isn’t 0.75" clearance under there. The other is that the UI won’t let you enter 0.75" for your material thickness or it didn’t used to anyway and the visual alignment would have been even more off than it is normally. Maybe you didn’t use visual alignment though.
Another tip. The 3/4" board that you tried is way higher than the air assist port just behind the laser head. On my machine that port is only 0.6" above the crumb tray. If the head had come forward a little more during the attempt the port would have hit your material. This will only ruin your engrave if you are lucky. The port could actually wedge against the material.