I left a bit of extra length in the shaft, turned down to the size of a large pulley I have from a tumble dryer, in case I want to mount a large disk for a disk sander. The pillow blocks take a 1" axle, and the axle material was 1" square before I turned the ends down on a friend's lathe (thanks Steve!).

The end frames are all of 45mm x 90mm pine. Notice how the legs are half-lap jointed to the crossbeams, to retain rigidity and strength.