I have a Monport 40W Laser Engraver/Cutter and I am trying to cut 1/8 and 1/16 acrylics to make earrings. Pretty simple designs using mixed of marbled/pearl and frosted color acrylics. I have tried every variable I could think of. Passes, speed, power - lowering, upping it, less pass, more pass, removing air assist. I can’t get a smooth edge and now it chars. Sometimes it doesn’t even cut all the way. Lasers have been aligned (or so we think). If it cuts at all, it’s an ugly cut with burn marks or really scratchy on the sides. Please help with any setting/variable suggestions.
I don’t have a co2 machine but I think if it chars is is synonymous with heat concentration.
You maybe need to check if the beam is well focused.
Take a look on this topic, maybe help you
Have you checked S-Value and $30 value are set the same ?
yes they are the same
it’s just impossible to align the lasers in all four corners of the machine. Any foolproof way to align these mirrors and also to focus the laser beam?
I’m not an expert on the subject (far from it) but if you’re looking for great results you need to great good conditions.
If you can’t focus on the four corners I would take that into account and try to correct it. 
The manner in which it’s impossible may point to the problem.
Adjusting the mirror angles using the small screws on the mirror holders gets the beam path parallel to the axis motion, so that it will burn a single dot into a target on each mirror at both ends of the axis.
Then you must adjust the mirror position by moving the holders laterally to center the beam in each mirror aperture. This always requires readjusting the angles, because it’s impossible to move the holder without also changing the angle.
After you tweak the beam into being both parallel to the axes and centered in the apertures, then it’s properly aligned and you can proceed to focus adjustments.