ATM Mirror Grinding Machine Mark II (under construction)

Part 2

Chunk
Well, as I described the mirror blank and tool got stuck. One of the centering bolts sure applied some pressure, resulting in this fine (is fine the correct term here?) damage, which is 45 by 23 mm in size (1.8 by 0.9 inch). Sigh.
Tool worn out
After a total of about 5 hours on the machine the tool wore out. At first I noticed some tendency of the tool to ride up against the blank and didn't worry, just added grit and water until it rode fine again.

When it was time to check with the Spherometer I found out about the tool. Now I am attaching new tiles with a PU glue, hoping that it holds the tiles.

After the first hour of polishing

Another hour of polishing, the tool moved in by 5 mm (0.2")

Still a hill in the middle, 4 wavelenghts high