Thanks, this is just the kind of info I was after.

Do you bolt them to the floor? I had originally planned to put this on
the same mobile base I make for everything else (for the inevitable
move or if I want to rearrange things temporarily). My mobile base is
either 2x4s or 4x4s half-lapped into an X pattern so that they pass
under the four feet of the machine, then lagscrewed to the machine.
The length of the 2x4s depends on the top-heavyness of the machine.
And I usually over-do the casters so that they have big wheels. The
manual says to use expansion bolts in concrete though in order to avoid
vibration. Seems a bit excessive to me.

brian