I have an fox Alien laser 40 watt and running at 200mm/m at 80 % and still will not cut thru 3mm plywood. Is my wood the problem or the laser broken?
My .02 cents from a newb. Slow down the speed, and make sure your mirrors are aligned, and your in focus.
Have you tried 50mm @ 50% pwr, 50mm @ 60% pwr,etc…
Are you sure your mirrors are properly aligned?
Is the wood finished or bare?
Is the Plywood a light colored Birch plywood?
Switching materials will almost always necessitate changes in speed and power settings.