I’m running an xTool 10 watt D1 pro, I took off the orange cover because it was getting caked with wood crusties after an hour of engraving with air assist.
xTools air assist has a rotary dial for the speed. Even without the orange cage, there will be crusties built up around the nozzle head after a couple hours of engraving with the air assist on, it doesnt matter the speed of the air.
The build up is always on the opposite side that the nozzle is screwed in, And it builds up around the laser hole as well. So after an hour or so, depending on the material, I’ll pause the program and take a q-tip and gently clear the crap around the nozzle.
So even running air assist, you’re going to have build up around your nozzle.
I discovered this too. My air assist is set to just slightly pressurize the nozzle when engraving. When removing a part, it touched the nozzle tip and left a mark. This was after 12-15 hours of burn time. I figure cleaning after a couple of hours run time should be enough.