I have been using my D1 Pro 20 Watt. I have been working on a project cutting out 3mm basswood. 100% Power 7 speed. It was working perfect. Shut down my unit and the next day went to work some more. I of course cleaned before I started, and my cuts seem to be burning more material than normal. Not horrible but for instance if I cut out a square the corners aren't sharp. They are rounded a bit almost as it the laser is burning too long. My alignment to the frame is square. I adjusted the focus and even did a test cut array. What is also funny is my laser seems a little inconsistent as far as cutting through the material. I would up the speed or lower the power, but it doesn't always cut through the material. See picture below. It's real hard to see but the cut array on the left the cut line around the square is slightly thicker that the array on the right. The squares look softer as well. Almost like the wood has some sort of pull back from the laser cut. Any suggestions would be greatly appreciated.