Hi boydage,
if you have only 200mm of clearance under the gantry then quite a few of the rotary tables we've discussed are not really going to fit.
Even if the entirety of the rotary table does not pass underneath the gantry the workpiece and vice/workholding need to be able to rotate, for a rectangular part it will rotate in 90 degree
increments, and must perforce have a radius of 100mm or less and the centerline height would want to be 100mm above the table.
I rather think the device you linked to at the top of the thread and the Tsudakoma units I saw on Ebay are just too big. I'm at home at the moment but I will measure my fourth axis
and post, probably later today.
I think some of the smaller direct drive tables that Ardenum linked to would fit. The one he recommended was 200mm in diameter, so you might not have clearance with
that model but might well be OK with a smaller one.
I see you are from Nelson, and I if you have not already worked out I am in Christchurch. Maybe you'd like to borrow my fourth axis for a while to see if it works?. I use it but not that often,
in fact less that I thought I would...but that's another story. At the moment it has a 3-jaw chuck which is fine for round stock, but if you used a 4-jaw, it would hold
square/rectangular stock, and would be a comfortable fit for parts in the region of 100mm square. Borrow it, use it and see whether it works well enough and that it useful for your purpose
without having to spend all that dough......your wife might want it for something.
Craig