I am looking for feedback from anyone that has experience with laser cutting impact modified acrylics (polymethyl methacrylate, PMMA).
Our team has a 130W Thunder Nova 51 laser cutter and a Velox VR-5050 CNC router. We use the laser cutter to make lots of prototype parts, mock-ups, etc. out of acrylic for testing because it is very fast to go from idea to CAD to physical part literally in minutes. When we settle on a design we then cut the part out of aluminum or polycarbonate as appropriate on the CNC router. This work flow has been very effective for our team.
However, I would love to find a more durable plastic that can be cut as nicely as acrylic on the laser cutter with material properties closer to polycarbonate that could actually be used as a “polycarbonate substitute” where appropriate on the actual FRC competition robot. Acrylic has very limited use cases on FRC robots in my experience.
I have researched some on impact modified acrylics such as “Acrylite Resist” and “Duraplex”. There are other brands. They all seem to be much more durable than standard acrylic.
Each of these brands of impact modified acrylics come in different grades like 45, 65, 70, 75, 100. The “100” grades seem to be comparable to polycarbonate in terms of impact and resistance to breaking.
The “Resist 65” grades seem to be fairly commonly used in store displays and such. Here is the MatWeb for “Acrylite Resist 65”:
It also seems to be easily laser cut like regular acrylic sheets, however, when it is laser cut it tends to leave a sticky/tacky edge. Supposedly this sticky/tacky edge can be removed by wiping the edges with VM&P Naptha to clean them up:
Does anyone have any experience laser cutting impact modified acrylics and using the resulting parts on actual competition FRC robots? How durable is this material compared to polycarbonates or maybe acetals? Is it a viable laser cuttable “polycarbonate alternative” for FRC use in appropriate applications? If you have experience with using impact modified acrylics on FRC bots what grade(s) and brands have you used? 65?, 75?, 100? Acrylite Resist? Duraplex? Some other brand? If you have experience laser cutting impact modified acrylics, how sticky/tacky do the edges come out of the laser cutter? What secondary processes have you found work well to remove the stickiness? Naptha? Lightly sanding?
With laser cutters becoming more and more common in FRC shops I’m wondering if impact resistant acrylics may become a more useful material to teams. I just have no experience working with impact modified materials but am willing to get some and run some tests but would value any insights others with experience would be willing to share.