Cutting "Inventables" acrylic without burning? Help!

Hello!

We are relatively new to using our Glowforge and laser cutting in general. We work in a pediatric hospital and are trialing how we can use the glow forge to create legacy building items for families at end of life. We are focused on wood and acrylic at this time to try and get the basics down. We started by using the proof grade materials through glowforge and really had no issues after reading through the forum/everyone’s recommendations.

However, we are wanting to try engraving on two toned acrylic for hand prints, so we purchased Matte white on gold engravable acrylic through Inventables website. We were able to engrave successfully however are struggling to cut without seeing a larger than normal flame. From our trial and error process, we have a couple of questions for people who know a lot more about laser cutting than us:

  1. Is there a difference between laserable and engravable?
  2. What settings do people use to cut on inventables 1/8 acrylic?
  3. Are there any other recommended two toned acrylic companies we should try?

We appreciate any insight into how we can make some really great products for our families!

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“typically” acrylics are similar from one brand to another. I use the PG settings. Acrylic is something you really need to watch. Monitoring this forum it seems most fires come from acrylics so standing and watching it cut is always a must for me. I’ve used several different brands and haven’t seen a huge difference. I’ll see what others chime in with their thoughts too~

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Thanks for your reply. That’s good to know about acrylics all being similar as well being more prone to fires. We always watch the entire time to make sure, even with our wood products! Our first attempt was with the proofgrade setting and it was the only time we were able to fully cut through. However there was a large flame and it got very smokey, which we had never seen before when cutting other acrylics with the same setting.

Did you remove the film from the Inventables acrylic before cutting and engraving? I have the matte Black on Silver from them and don’t have any issues. Also, excess flames are sometimes indicative of fans that need to be cleaned. Have you cleaned your air assist fan recently? How about the other fans?

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Laserable is generally cast acrylic, less brittle and more definition to the engrave.

Engraveable for two tone (sandwiched) acrylic is often extruded which is more brittle and when broken tends to shard. It’s also “less defined” when engraving from the traditional sense of contrast between the engraving & the material. But for two-tone/ply acrylic that’s actually a good thing as you’ll burn the top layer off & not have the frosted look of cast acrylic engraving.

I’ve had success in using both with the laser but I choose the material for the effect I’m looking for.

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As with any settings question, I give the old “definitely do a material test” advice. Check out #6:

Once you figure out that test method, you’ll always be able to figure out what works.

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We did remove the film, yes! And we will definitely try and clean the fans. That is not something we have thought of since we have only been using it for 2 months and have only had it cut about 20, inch sized products so far. We haven’t had a flame on any other product besides this acrylic.

As @dklgood said;

… or a filter that is reaching its end of life. Do you use a filter or vent outside? Once the filter face-loads it restricts airflow, which would manifest as small flair-ups where that didn’t happen before.

“pediatric” and “end of life” evoke heartbreak and exist on a scale of nightmares. The handprint idea is a very thoughtful gesture. :hearts:

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Thank you for attaching this link! We will give that a try.

We have the glow forge filter with the hose attachment and use that since we do not have access a window. We will check the filter to see if that is the issue. Thank you- we like the hand print idea as well :slight_smile:

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The filter has a fan speed adjustment, and as airflow restricts you can turn it up to move more air. once the fan is at its highest setting and you are still getting excess smoke, it’s time for a new filter element.

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I thought the difference between laserable and engravable was that one was laser-safe, the other is really meant for a cnc machine to be engraved via drillbit. Was I mistaken? A lot of the 2-color acrylics/plastics are both so they are in either category, but I was thinking CNC when it said engravable.

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Good question. :thinking:

So the acrylic we bought that I linked to the post, states “This acrylic can be engraved using a 3D carver, as well as a laser cutter” but it doesn’t say it can be “cut” with a laser cutter. What you are saying would make sense actually. Maybe the reason we had an easy time engraving is because it is ONLY engravable and not able to be fully cut with a laser, only cnc machine?

How thick is it? The laser safe ones should be OK for both cutting and engraving. But if it’s too thick, that would be an issue.

If it was only meant for cnc, it wouldn’t have laserable on there.

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I am confident the acrylic material you reference can be safely cut with the laser. I have had success using the Proofgrade medium acrylic settings for cutting and engraving. To clean up the engraved area you may want to consider a second defocus pass at high speed.
Another supplier of two color acrylic is Johnson Plastics Plus. They are owned by Rowmark, the company that supplies a large portion of acrylic for the sign industry.

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Sort of.

The laser can cut either one. It can engrave either one as well.

But laser engraving a two-tone “engravable” not “laserable” is sub-optimal. It will engrave but it’s hard to get the settings just right so you get rid of the top color to expose the bottom color. And because it’s burned away and not carved away, you get top color deposits on the bottom color engraved surface.