Thick acrylic

[Tom_A]

Has anybody attempted to cut “thick” acrylic?
3/8"?
1/2"?
3/4"?
If so, how were your results? Any advice?

Thanks!

[tom]

I have done 1/2" in 2 passes with great results. I believe @karaelena has also. I do not recall the settings but know it was close to the slowest.

[Tom_A]

@tom

I have done 1/2" in 2 passes with great results.

Thanks for the info!

Here’s the thing… I’ve never done multiple passes on anything at all. Is the 2nd pass needed because it simply can’t cut through in one pass no matter how slowly? Or is it simply a cleaner way to cut through?

[wesleyjames]

Well, you could probably get through the acrylic…but you’ll probably have sloping slag instead of clean cut lines…might even have the slag melt back together…or drip down the honeycomb.

[AhnoldZ]

Not as many responses as I expected. So do a search using the terms ‘3/4 acrylic’ or ‘2 pass acrylic’. You’ll find a lot of useful info.

For example:

Lumosforge is here!

Yeah, it really didn’t seem like 5 hours! Time flies when you’re having fun. Well, I tried to resist saying it, but the Glowforge really is bigger in person. And this is coming from someone who already owns a laser cutter with a very similar width as the Glowforge (within 1 inch). And it really is a sleek lookin’ machine; it looks better in person as well, IMO. So… let’s see, what did we do that whole time? I guess if I was a better planner I would have made up a list of things …

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: [MVIMG_20171031_202744] And, the first fire I had to put out. It was time for something more methodical. I give you: [Untitled-1] 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 completel…

Melty - ish inside edges when using Acrylic - Settings help?

Hi. I cut my first acrylic using GF last night. I used black proofgrade. When the cut was done and I removed the item, the outside lines were clean but right inside there is a wavy melty-ish line that I can see. I have not had this happen with other laser cutters that I’ve used. I allowed the app to select the setting based on the material but am I just going to need to play with the settings to avoid this, is there some kind of settings chart that I’m not aware of, or does this just happen wit…

Multipass

This question is about multiple passes in laser cutting/etching. For Leeloo Dallas information, see Fifth Element. As a laser-noob, I’m trying to understand when I will want to use multiple passes. Is it a matter of tough materials to cut/etch? Is it a matter of what will cut/etch “nicely?” Is there a best practice for multiple passes? Looking for some general insight here. Thanks!

[Tom_A]

Thanks so much to all that have replied!

I’ve gone ahead and ordered 1 sheet each of 3/8", 1/2", and 3/4" and will perform some experiments. I’ve got a couple of projects in mind and, I must say, I’m pretty excited to see how well I can make it through the 3/4".

Stuff should be here on Monday. I’ll be happy to share my testing results in Beyond The Manual.

[jbpa]

I vaguely remember @scott.wiederhold posting the results of some testing with 1/2" acrylic.

[Tom_A]

So! I got my acrylics today! Here’s what I found…
The 3/8" cut cleanly at 100/Full
The 1/2" cut cleanly at 100/Full x2
The 3/4" cut cleanly at… No… I could not get it to cut cleanly. Closest I’ve come so far is 120/100 x14. Yes… I said 14 passes. Came pretty close to clean, but you can tell the last couple of passes it got a little melty. The only answer would be if there was some machine that could easily do two-sided cutting.

[jbmanning5]

At 3/4”, to have a fighting chance, you’ll need to refocus at least a couple of times, I would guess.

[Tom_A]

@jbmanning5

you’ll need to refocus

I was considering that. But I don’t know anything about doing that, so I don’t know which way to go. I’d think I’d need to refocus deeper, right? So instead of (using nice round numbers here) my focus being set at 0.75", would I want to go 1.00" and do a few more passes at that focus?

[jbmanning5]

Start high, go low. You’d want to get the acrylic shimmed up pretty high. Between 0.4-0.5” above the crumbtray. Your initial pass would be at surface height. Then you’d have to go lower, maybe/probably as low as it would go… .01” - which would still leave material below the focal depth but might work. Maybe do the 2 full power passes that cut 1/2” and then refocus on third pass to see where that gets you.

[Tom_A]

@jbmanning5

Start high, go low.

I get what you’re saying now. I’ll give it a shot tomorrow night.

[tom]

Also propping it on pins or something so that the air assist has someplace to go helps with a clean cut

[Tom_A]

I got decent results on the 3/4" (actually 0.72") at 115/Full x5. It’s not perfect. But I think I can live with it. I’m going to produce something I actually want to make out of it and see what I see.