I have recently switched over from the rotary cnc world to lasers. Specifically for making legend plates for Industrial Control Panels.
I am very happy with the quality I have been getting compared to the struggles of doing it all on the cnc.
I have an omtech mf1624-60 which is a 60 watt CO2 machine. I believe the focal lens is 1.5 inch but have not been able to find a confirmation on the omtech website.
For engraving the plastic I have been running the machine with a single pass at 100 mm/s and 7.5% power and ~740 lines per inch.
I do my cuts first, peel away the plastic that comes on the rowmark material. Then I do a light coating of dish soap, let it dry and do my engraving.
This methods has been working well. I get a clean finish on the surface and all the residue from the engraving washes away with the soap.
I would like to improve the finish on the engraved areas. I am currently getting some noticeable lines.
That is extremely high, because the typical focused spot size will be on the order of 0.1 mm = 250-ish DPI. In effect, you’re plowing the same row three times and producing furrows.
Run a Material Test varying the scan interval from 0.05 mm to 0.2 mm and the power from 7.5% [*] to 20% to see if any of those look better. You may need a speed vs. power test at whatever the new scan interval works out to be, but the first test should get you started.
[*] I’m mildly surprised it fires reliably at 7.5%, but if it works for you, have at it!
