Cutting Acrylic. Bit or laser

How To Machining
1

A recent thread mentioned cutting Acrylic wit a laser.
Honestly my brain never went there.

Anybody have some pros and cons of using a bit versus a laser ?

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A laser seems more convenient if you’ve got proper ventilation. Though acrylic is usually cut with a CO2 laser which comes with some annoying upkeep/maintenance.

You can’t really do 3d so you’re probably just engraving and cutting with a laser. If that’s not a limitation, profiling flat acrylic with a laser seems much nicer than dealing with a cutting tool and obnoxious acrylic chips.

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Acrylic cuts very well with a laser. Before Carbide, Jorge and I did a lot of prototyping with acrylic, delrin and an Epilog laser. We paid a lot for that machine and it paid itself back at least 10 times over.

The cons? Laser has a bit of a kerf, the Epilog was about .01”, and you do get a taper on thicker materials.

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4

I hadn’t thought about laser cutting delrin. From the little injection molding I’ve done with it though, there’s a bunch of precautions to prevent vaporizing it into formaldehyde gas :mask:

Is laser cutting it just the usual precautions? Good ventilation, ideally exhausting outside. Or were there special considerations?

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With the Epilog, we bought a pretty large blower that vented to the outside. The only plastic that you had to avoid was PVC, because it created chlorine gas (if I remember correctly) when cut with a laser.

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Yes. And sometimes fake leather is actually made with PVC at least for use in baseballs and softballs. It is really hard to identify whether those are covered in real leather, or a fake leather and whether that fake leather contains PVC.

The gas it produces is of course bad to breathe but I also hear it is corrosive for the machine.

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7

At work we have access to a large format Omtech CO2 laser cutter and a few Shapeoko machines.

Laser Pros:

  • Quicker to setup than a CNC router.
  • Ours has been low maintenance.
  • We have good ventilation options.
  • As long as the material is laser-able, it cuts floppy materials easy. We use it for gasket making material for example. This is harder on a CNC.

Laser Cons:

  • Has to be ventilated.
  • Has to be CO2 for clear acrylic. Diode lasers use a visible spectrum of light, so it passes thru the clear and doesn’t do much if anything. CO2 is usually infrared spectrum, so the acrylic catches the energy and cuts.
  • Can’t cut some things, mostly as noted stuff that has PVC as it makes gasses banned by the Geneva Convention. This Delrin is cuttable, but is…odd to cut. Most magnet material is very PVC based.
  • Can only cut profile cuts and engraving. You can’t do 2.5D or 3D features.
  • The kerf can make fitment interesting. With things like finger joint boxes I spent a good day dialing that in, and saving settings for various thicknesses. Also, since the edges are not perpendicular and not super smooth, edge bonding can be tricky both due to issues with adhering, and the components not being perpendicular causing it to want to lean a little.
  • The laser tube weakens over time and is considered a consumable. So over the 3-4 years we’ve had to make adjustments to the power levels in our settings to cut completely thru and have clean edges.
  • When the laser beam hits the honeycomb it scatters a little. This can leave marks on the acrylic at times.

In short, I’m glad we have both options. Most of the time the laser does exactly what we need it to. But in our use case there are plenty of times we still use the Shapeokos to cut it.

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As always the cast of characters in this forum have real and intuitive experiences to answer a question. Thank you.

I will probably buy into a Diode laser because I am primarily interested in wood engraving.
JTech will probably be the source.
I did see the CO2 lasers produce a darker results, but I am still in lose money slowly mode.

Now if C3D would directly support a Laser …

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