Setting up work on the rotary table

[irving2008]

....., a dial indicator (DTI) needs to be mounted on a suitable holding device clamped to the spindle. Articulate holding device (indicator clamp) to indicate four sides (square part) or two opposite sides (rectangular part) and two 90 degree sides (again rectangular part) to indicate zero from x minus, x plus, y minus, y plus (hand rotating spindle then twiddle spindle to indicate zero). ...

Thanks for that. No, not too complex, and thats pretty much where I'd got to myself.. I was hoping someone had a clever solution that wasnt the obvious one, but why do i need to put DTI in spindle for rectangular part? Why not on bed, indcate side 1 then rotate table 180 and indicate side 2, then tap into place, repeat for sides 3 & 4?