Etching in 3/16" Acrylic. I just need a square of Acrylic removed. I want it not to be too band-ey, but there’s no detail to it at all. I’ve been using 1000/FULL, 270LPI (Proofgrade setting for SD Etch) but it takes SO LONG!
What do you recommend for lower LPIs ?
I’m not sure you can achieve the result you’re after any more quickly. You could try 225, but I suspect you’ll see some banding. Each band is overlapping still at 225, but since the laser isn’t perfect there is some drop off of power density as you move away from the focal point and that’ll be likely visible in a simple square.
Since you’re already at full power, defocusing the beam to get wider lines probably won’t help you since you might need another pass to get to the depth you’re after.
There’s a chance (if you’re using multiple passes) that a slower pass will get rid of more additional material. 225 or 175 might even work, but. I would consider defocusing to lose some of the banding.
Just defocus by ~ .18” and you will get rid of the lines.
I’ve done a fair amount of acrylic lately and if you aren’t concerned about detail, the slight defocus trick works pretty well. I’d probably aim for the 225 setting as a first try. Engrave with a bitmap does just take a while, plain and simple. I’ve been doing some ~3"x4" acrylic playing card cases and while pretty detailed, it’s been a 30+ min job for each.
'Tis what it is!