Slate burning on Ortur Lasermaster 2

I have been engraving slate tiles… using Lightburn…for about a month or so now, and for some reason, the last batch of tiles I have done, they don’t burn as consistent as the ones I have done before. Same process as all the others, but they don’t burn all the way through the sealant I spray before engraving.

I use a flat spray, let dry and engrave. Has never been an issue before. Some say it may be too much? I refocused the laser thinking that may be it, lowered speed, and still same result. Any thought? I run a speed of 50 inches per min 100% power

Thanks guys

I would run some power tests to ensure the same power is being emitted as before. You may be experiencing the diode starting to fail.