Cleaning up a couple of random boxes of 'stuff' today turned up a remnant of 6mm Acrylic so off to the Laser with it to help the cleanup.
Continuing on with a higher speed lower power engraving the 10% @ 300mm/sec is looking really sharp and clean. Maybe some very minor improvements to be made but unless you want to back fill the engraving with paint then this is about the correct setting.
I haven't tried cutting over 3mm Acrylic in the past so this was a quick Google some guesstimates on power and speed and call me amazed it was so easy
Several things of note focal range is important on thicker materials so set it toward the middle of the cut (adjustable bed is great!). The 4mm/s @ 70% is a better result than the 5mm but both released clean and you can see the edges are fairly well flame polished by the laser it is possible a reduction to 3mm might help but below is a different option that seems to work better again.
There is a very slight angle to the cuts (the parts still self stand so it is slight) and some visible Striations on the bottom of the cut. From what I have read this is caused in part by to much air from the nozzle causing cooling so I will be fitting a needle valve to the air system to reduce it for Acrylic cutting. This apparently allows the beam for focus the energy and heat with less cooling vertically through the cut.
I am thinking based on this that if needed 8mm Clear would be about the maximum cut for the laser but at that you are really into CNC Router or bandsaw territory with some edge sanding.
EDIT: Tried 2 and 3mm cut speeds of the tiny bit I had left. Cleaner but increased angle across the cut so air reduction is next.