Medium Frosted Acrylic not cutting through

I made a simple door nameplate, text engraved fine and twice it failed to cut out using the default proofgrade cut - it only cut about halfway through and i had to go back and do a second cut at a slower speed - the frosted acrylic seems a bit thicker to me, but it could be my imagination - perhaps it was mislabeled - ill try regular acrylic for a control

1 Like

I recently had a piece that was the same way. I did the same as you to cut it.

Was it the frosted also?

It feels like maybe glowforge needs to update the proofgrade settings for this material

Yes it was, I didn’t get a measurement but it was thicker than the clear medium sheet I had but not as thick as the thick I have.

You might want to check your Lenses, Mirror, and Windows of the laser. What looks like an inconsequential blurb on the laser window can seriously reduce the power of the laser and cause it not to cut as well as expected.
See this for a method of cleaning lenses

You also need to make sure the material is flat and the correct thickness (though that is less of a problem with Acrylic than woods)

I did a complete cleaning (including the lens) and the material was perfectly flat.

Are you sure the lens was put back in correctly?

Only halfway through seems to be a focus problem, especially if you just did a cleaning - either a problem with the autofocus value when it did its scan, or the lens is backwards causing the beam to be out of focus at that range.

1 Like

There are two windows outside the head, plus the lens and the mirror. I would double check the thickness being used as well. My experience is the Proofgrade settings are perfect only when everything else is, otherwise I kick it up some.

Everything was meticulously cleaned. Other materials cut correctly

1 Like

Then I would see what the proof grade settings do and kick it up a notch.I would also run a test on any material with a wide range of settings and save the test for future reference

Or glowforge could adjust the proofgrade settings. Isn’t that why one would pay more for the proofgrade so you don’t have to fiddle?


Indeed, and why I use non proofgrade and run tests. Someone borrowed my fiddle and did not return it, so I just go with the reference.

1 Like

Mine is clean as well. I got around to taking some measurements and the Medium PG Clear measures .109 the
Medium PG Frosted was at .143 had to slow down speed to cut all they way through. I checked 6 different pieces of Medium PG I had on hand and the all came in at .109 to .124

Well they should definitely update the presents then

I have had the frosted before and it was not thicker like this last sheet. Luckily I only bought one sheet of frosted when I ordered last.

Do you have calipers? They’re really an essential item. See if you can measure the acrylic. It would be very strange if it were a slightly different thickness since it’s such a standard material, but if it is GF should know about it. *I stand corrected, but still think a measurement would help!

It was a little thicker than the clear

You’d be surprised at the tolerances:

I’m not sure I would be that surprised. :slight_smile: Seriously, though, if it’s visibly off, a measurement would be good. Just saying it’s thicker than something else doesn’t say anything. Saying that it’s X thick allows GF to ensure it’s within their expected range and tweak settings if they need to.