The wood is laying perfectly flat. I have tried a few experiments with focus. This shows a setting of 140/full (used to cut through without a hitch) at focal points of .1, .2., auto, .3 and .4 respectively:
Okay, changing the focal point on it is probably going to prevent it cutting through in most cases. That looks like a huge kerf width on that first picture. You want to use a focal point equal to the thickness of the material or a hair’s width less.
The Glowforge program now comes with a Set Focus tool…have you tried it? Instead of having to enter the Focal Point or the Unknown Material thickness, you can just put your material into the bed, open your file, click the Settings Gear up in the top Row and choose Set Focus - then click on the center of your design. It does all the calculating for thickness and focal point now.
And for the smoke staining, the only thing I’ve found that works is masking it. The amount of staining showing there actually looks about light-to-normal for unmasked wood to me.
I thought about that too. I pushed the lens all the way in (carefully) with the blue thingy. Did a “cut” and then looked. The lens definitely moved. I’ll look at that some more.
I changed the focal point so I could see the difference in cut depths. It was, as I said, and experiment. It is a HUGE kerf. I had to set it to so slow that it scorched the kerf very wide.
I appreciate your help, Jules, but I’ve cut thousands of pieces of wood. I know most of this. Optics are all clean. There is definitely something else going on here.
This should not be an issue but if gunk was in anyway gumming up the focus mechanism it might not focus correctly and be inconsistent in cutting. Of course cleaning the “hidden” window off on the Left or putting the main lens in upside down need not be mentioned and would probably be more consistent in not doing the job. but perhaps removing the lens and mirror and trying to inspect the mechanism with an endoscope and posting pictures might help
I provided a photo of the lens. You can see that it is not upside down. Also, the machine does tick (stepper in head) when I turn it on and, as an experiment, I intentionally pushed the lens up inside the head as far as it would go, did a small cut, then looked to see if the lens was in the same position. It was not. So it does move.