Hi. i am building panels for simulator that is painted in black and white and i saw these 40w laser engravers on ebay and was wondering if that has enough power/good enough to do laser engraving on acrylic/polycarbonate panels that are painted? i only need to remove the 2 top layer of paint.
Or would it be better and cheaper to get all my panels engraved at a service?
Assuming it’s a co2 laser, you cannot do polycarbonate on it only acrylic
40 watts should be plenty to etch.
Alright thanks. Why does polycarbonate not work?
polycarbonate can’t be cut by CO2. you can still engrave the surface though, and for removing paint the base material doesn’t really matter…
yeah - it doesn’t cut nicely - balls up and discolors and can catch fire.
Okay thanks. I will mostly use the laser just for engraving
I know this topic is in reference to the purchase and operation of a private / laser.
For the sake of DMS lasers, am reminding everyone that we do not allow any polycarbonate (aka Lexan) on ours. Our list of prohibited and safe-ish materials is located here.
https://dallasmakerspace.org/wiki/Laser_Cutter_Materials#NEVER_CUT_THESE_MATERIALS
Thank you for letting me break in with this public service announcement. Happy Lasering!
@norsk22771 I have a K40 laser so if you have any questions let me know. The K40 is good for engraving and cutting up to about 3mm. It can cut thicker stuff but just becomes a hassle since it needs more passes. Also it has a pretty tiny work area 200mm x 230mm.
I’ve upgrade mine with a Cohesion3D controller and RaspberryPi/Touchscreen to make it wireless. I just roll it out to the garage to do my cutting.
As I recall another reason for not lasing polycarbs is that it vents chlorine/chlorinated gases. Highly toxic and acidic.
Polycarbonate can be cut but shouldn’t. It produces carbon monoxide and it turns yellow and brown. A 40 watt CO2 laser will be able to burn through paint no problem and cut most acrylic.
Soo my plan is to use a 3D printer to print out the panels (3D printer will be used because of werid angles and i need other stuff that need to be 3D printed) Then i sand the surface soo it is smooth, paint over with a few layers with white paint and then switch to black matt paint and then use a laser to engrave the black paint away.
But is it dangerous to engrave just the paint away on polycarbonate? EDIT: Will not use Polycarbonate
I see there is other materiels i can use for 3D printing, something called “PMMA” witch they say is acrylic filement. the question is can i maybe use that?
Another question i have when it comes to acrylic plates. Is it possible to use the laser to just remove 5mm of materials? if that is possible with the cheap k40 china laser then im good 
and can just buy arcylic plates
Is it also bad to engrave on PETG?
I suspect tuning the laser so it would ablate the outer layer of paint without affecting the inner layer would be extremely difficult to do. The paint is burned off by the laser, so the white underpaint would burn as well.
Using black plastic with white paint might work (but would reverse your color scheme). White lowerctemp plastic (like ABS or PLA) might discolor under the laser-burn as well, so using a white base likely won’t work.
You’ll need a flat surface to use the laser on (it won’t focus consistently on sloped surfaces), so I’d reconsider cutting the panels out of black acrylic on the laser as well.
You could cut into black acrylic and rub white acrylic paint into the etched lettering. You could use 3D printed parts to connect the flat panels. This can be done at odd angles (see this globe I lasercut as an example). It used small pentagonal pyramids in the corners to connect the lasercut panels.
A (somewhat pricy) two-layer acrylic sheet for making nameplates is also available. You laser-etch (or route) through the top layer, exposing the lower layer. This makes for crisp lettering in a contrasting color.
You can get it at Allied Plastics.
Hi again. Im wondering How powerfull of a laser do i need to engrave on black painted acrylic? i am looking for cheaper lasers and i found a 2.5w laser and was wondering if i could use that for engraving?
Are you talking about engraving, cutting or both?
A 2.5w diode can cut and engrave black acrylic, but it won’t be fast.
I own this one, pretty happy with it.
Just engraving
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