1/2" Cast Acrylic

I had a need to made some parts out of 1/2" clear cast acrylic. I bought the material from Inventables using my GlowCredit, and after a few stabs in the dark, wound up with this mess:

And, the first fire I had to put out.

It was time for something more methodical.

I give you:

These are single line, 1/2" in length cuts at various focal depths and cutting speeds. All are at 100% Basic Power.

.433" at 100 GlowySpeed gave fairly consistent cuts completely through. There were a couple of spots that didn’t quite make it (or melted back together, don’t know which), but for the most part it was a full cut.

After deciding that .433" focus was giving the best results, I made the multi-pass attempts:

2 passes: 125 (barely), and slower all cut clean through. 100 left an undesirable undercut on the bottom.

3 passes: 140 and slower cut clean through.

Best bets:
2 passes at 120 was the best for a quick cut, with a kerf of .014" measured at mid cut depth.

3 passes at 120 left the cleanest looking cut, the least amount bottom distortion, and the same kerf:


The graph is great. :sunglasses:


Graphic designer I ain’t… :wink:


Some very useful testing. Thanks for sharing!


That is so helpful, thank you. Russ at SabarMultimedia would be proud of you.

My pre-release always did the thick acrylic in two passes as default. Somewhere along the line, the defaults changed, but I really had to keep my early unit on to two passes.

A little clarification for me, I’m not quite figuring this out. 2 passes at 120 was a quick cut, but 3 passes at 120 left the cleanest cut and least amount of bottom distortion. But both went all the way through?


They both went through, and without any ‘stuck’ parts. But, the 2 pass version leaves a small flare at the deepest part of the cut. Gives the piece a seventies throwback look (bell bottom).

The 3rd pass removes that flare, and has a small polishing effect on the cut.


Thanks for the test and numbers. It could not have come at a better time.
I have to make a couple of filter supports for my Glowforge filter I am building.

Yep he went crazy and is making it out of 1/2" Acrylic, and over built too.

I will have two of the carbon filters after the replaceable pre-filter. The left side in the picture is the 4" inlet, 12"x20" pre-filter and then the two carbon canister filter and 4" outlet. I have an exhaust fan that is 250 CFM I will add to the outlet side. The top will be removable for replacing the filters.


Very handy, thanks for sharing! :grinning:
(Added a Settings tag to your post so we can find it again.)


Thank you!!! This is why I heart GF and its community.


Your testing is much appreciated! I’ve bookmarked, and recorded your notes. Thank you!

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Very cool! Thanks, you have way more patients than I do. I have heard that getting it up off the honeycomb can help a lot too, in this case I guess you would need to remove it because of height restrictions.

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Yay, research and sharing!

I’m curious what settings to use to set it on fire…

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Wow. Half-inch.

FWIW, I’ve had a lot of issues with 1/4"" and cuts melting back together, especially if I make other nearby cuts.

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That was during my “click and burn” early sessions. I think those were something like 3 passes at 100 with a .250" focus. The acrylic turned to a Jello™ like consistency.

Was kinda neat until the flames started getting big - FAST.

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I was making this part:

Pivot Block_X2_500

Which is only about 1/4" of material, all around, so melting acrylic was a definite issue.

With 120/Full/.433" at 3 passes, it came out perfect.

Though, I cut two of them in the same operation. So the passes alternated between parts. That may have made a difference, as it would give a little bit of time for heat to dissipate.

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Outstanding guide. Thank you!

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Great guide! Thank you! I don’t have my Glowforge yet, but on other units I use, multiple passes on acrylic that thick always works better. Less melting and distortion.