Acrylic Cutting 2.8W Laser Upgrade Kit
So we get a lot of questions on whether the lasers can cut acrylic… The answer is YES! Now the 2.8W laser has enough power at manufacturers specified current to cut through acrylic with enough speed to make it worth it!
The sample in the video and the pictures is from our optical acrylic shielding (we had defect pieces laying around the lab) so we decided to give it try. Depending on the material, you might need to adjust the speed or power to get the process you want. Many customers say it works great on different kinds of acrylic from opaque black, blue, and brown to semi transparent like the shielding we have.
The parameters for our test were:
|Material:||1/8″ semi-transparent acrylic|
|Driver Current:||1.3 amps|
|Approx Power:||1.6 W- 1.8W|
|# of passes:||3|
|Z change per pass:||– 1 mm|
Cutting the thicker pieces like the 1/8″ acrylic requires that you change the Z depth for each pass to make sure the focus stays on the cut zone. Start with focusing to the top of the material. Then, divide the thickness by the number of passes and change the Z depth down by this number on each subsequent pass. For example: a 3mm sheet (~1/8″) will have the first pass at 0 Z (focus). Then the second pass would be at -1mm and the third pass would be at -2mm. This allows for the laser to have the focus be precisely at the cutting level for each pass.
You can increase the power a bit more and get it to go faster and less passes but we like to run things at a minimum level to show the “worst case” scenario when trying out new processes.
The video shows an extra pass which just cut through the sacrificial layer underneath. We left it in the video because it is kind of neat looking with the reflections in the acrylic. We repeated the star with just 3 passes and it worked fine…
As always, make sure you use adequate laser safety gear when operating any high power laser.
**update 1/2019 – The new shielding we ship is a reflective shielding and not absorptive, so it will not cut easy anymore. These videos are of the older shielding we shipped in 2014.***
Check out the video!
Cutting various types of Acrylic
We have tried several types of acrylic and found each would cut but at different rates. Most fell within the 40 mm/min to 75 mm/min with either 3 or 4 passes. The hardest to cut was a generic white acrylic from the hardware store. It took 5 passes at 25 mm/min to get through. The take away from this is that it can cut acrylic, but depending on the type (there are a lot of different ones out there) and the color (white is harder), it might be a slower process. The trick is to find the acrylic for your project that can cut as fast as you would like. For some, taking 30 minutes to cut a project is not a big deal. Sit back and relax and watch the magic!
Here is a small circle cut in the hardest acrylic to cut we found:
How far was the laser from the material on the first pass in this test?
I set the focus of the laser at about 3 inches off the top of the acrylic. The G Code program then moved the z axis down 1 mm after each pass to make sure the focus what down into the material to cut. I like to keep the laser at about 2 – 4 inches above the work surface so smoke and debris does not get on the lens, but it is adjustable to whatever distance you want.
Is it possible to cut clear acrylic?
would it take more passes to cut through thicker acrylic?
Yes, it will take more passes to go though thicker materials. Darker acrylics will cut the best. Transparent sheets will not cut at all (except for our laser shielding).
Can the bigger laser cut thru 1/4 acrylic? And what about making 3d designs in acrylic can this do it also?
Yes, the 3.8W laser can cut through 1/4″ cast acrylic (depending on the color) but it is not a very fast process. Flat black will cut the best. To get through 1/4″, you will need to do multiple passes and have the laser move down for each pass. Typically the feedrate will be somewhere between 25mm/min and 250mm/min with multiple passes.
I’m wondering how this was achieved.
My experiments with 445nm 2.5W laser and black acrylic discovered that laser is melting the top layer of the sheet and the cut closes immediately after the beam. I guess I have to either remove the liquid plastic with air jet or chill the cut somehow to prevent its closure.
It depends on the type of acrylic and also the color. Black will normally cut very well, especially if it is not shiny on the surface. The best acrylic to cut is CAST acrylic (sometimes called Plexiglass). Other thermoplastics like polycarbonate (Lexan) will tend to melt and catch fire. They do not cut very well at all.
Would it be possible to engrave clear cast acrylic at a depth of 1/16″ to 1/8″ inch?
Engraving on clear acrylic is possible, but it will not be too deep. You need to keep the paper on the top, use black paint, use sharpie, or use painters tape to engrave on it first, then peel or take off the coating to reveal the engraving. Here is a picture showing the engraving: https://jtechphotonics.com/wp-content/uploads/2015/05/laser-engraving-clear-acrylic-445nm-laser-finished-600.jpg
Hi, I am new in laser cutting, but is looking for one to cut 2mm & 3mm clear acrylic for my small project. Any recommendation ?
Our lasers will not cut clear items as they are in the visible spectrum. They can engrave on clear if you leave the paper on it. For cutting, you will need a CO2 laser at 10,000nm wavelength.
I am hoping to use the 4.2 watt laser to cut 1/8 and 1/4 inch matte black extruded acrylic. Thoughts or tips?
The 4.2W laser will be slow to cut 1/8″ and 1/4″ acrylic. The 7W would be better, but still slow. Both would take multiple passes at 10inch/min.