I just noticed that the build table shown by s3d is too large.
I have a delta printer and the usable build volume is 170mm diameter and 240 mm tall and that's what I have set in Tools->Options->Machine. In Options->Visualisation I have set the minor grid line spacing to 10mm and the major to 50mm.
The build table shown has a diameter of about 240mm (yes, curious that is the build height but I think it is just a coincidence) . Moving from the centre to the edge in a N, E, S, or W direction crosses 12 minor grid lines but it should be 8.5 (aka 85mm). More curious is the fact that if you move from the centre of the build table in a diagonal direction (e.g. NW, NE, SE or SW) then you cross about 8.5 minor grid lines to get to the edge of the build table which is the right number of grid lines to cross!
So it looks like the build table is too large by a factor of 1.414..