Nothing special. Just a puck lying on floor, a big washer as bearing plate (there is going be slight camfer on ID hole) and a carriage bolt to provide concave surface to allow a little tilt.
The screw is differential screw, but I don't know if it works good enough. M12x1,75 vs. M16x2,0 was the combination that came with tyhe tools I have and standard bolts. I would have prefered much M12*1,5 but that is not a standard. M10 but it looks thin and Could not have used standard long nut.
This screw gives a very sensitive adjustment range, downside is that there is very little of height adjustment overall. I need to get the machine fairly close to level to start with. This Grinding machine has three mounts. I'm planning to put single non differential screw on rear, get it fairly close, and use these more sensitive ones on front feets.
Started cleaning the lathe and chuck to change ouside jaws for hockey pucks and the chuck seized...not solid but I was not confortable to use use any force. Vacuum cleaner and a fiddle did not help, I took it out, dismantled and cleaned inside. There was very little debris inside...bit it was a piece of swarf between chuck body ways and jaw tooth. It's all it takes.