Made this one a couple months back...
I needed a roller base to move my jet cabinet saw into my tool room when not in use. My shop isn't big enough to have everything stationary. This base is square and rides about 3/8" above the floor.
I used 2" x 2" x 3/16" angle for the frame.
3" x 3/16" flat bar for the castor mounts with a piece of 2" x2" x 1/4" angle 2"wide welded underneath for support.
The locking castors are 4" and rated for 300lb each.
Mig welded with .035 fluxcore.

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