I got tired of fighting with my piece of junk milling vise and bought a Kurt D688 for my PM935TS, so I thought it would be a good time to tram the mill. It wasn't that far out, so I started with a Starrett Last Word indicator on an arm from the quill that read to +/-0.0005". It was acting a bit finicky, so I switched to a Brown and Sharpe which read to +/-0.00005". The thing that I noticed with the B&S indicator was that when I put pressure on the mill head, I could see the thing move. The indicator moved by about 0.0007" when the indicator was furthest from the mill on the Y-axis and about 0.0003" when it was at the shortest distance on the Y-axis. I was giving the milling head a pretty decent shake - maybe about 30 lbs or so. Is this normal? All the bolts and the gibs were tight on the head. I couldn't see anything that could move...can the cast iron really flex that much? Anyway, I was able to get the head square to 0.0002" over the depth of the table and mounted the Kurt vise. Squared it to within 0.0001" over its length and ran a test by surfacing the top and bottom of a 2x7" piece of Al and it measured within 0.0002" top to bottom/end to end so I was pretty happy...especially since I was lucky to get within 0.005" with the old junk vise I had. Also added a power feed on the X-axis and a DRO...I should have done that a couple of years ago. They're awesome.