Topic: Hand lapping the print bed
All,
In my glass bed addition I took a chance to hand lap the print bed. It was significantly not flat. If anyone is interested, I took a sheet of glass to ensure flatness. I taped a full sheet of Silcon Carbide sand paper. Slowly sanded flat. I started with 120 grit and ended with 600 grit. My preferred method is to slide left to right until all the scratch marks go that direction, then switch to up/down. Similarly move up / down until all scratch line up. Eventually you'll have a mirror finish.