Hey! There was discussion about transplanting a new robot brain into the old roland, and perhaps re specing the spindle to er collets, which would solve the problem of custom collets. Anyway, I am really interested in this, the owner was saying the intent was to match the software with the cnc router, and that also the 4th axis would be supported with the new brain. A ground mount for a rotary table is now possible with the surface grinder in the shop… I think given the small size, and capability of the frame (it is very well built for a desktop, and there is no modern equivalent) that would be a way cool capacity to have in the shop (4 axis desktop, metal capable) Disclaimer… I have a desktop cnc lathe that needs a new brain too… and would love to lean via osmosis and helping on this one.
https://www.micromark.com/3-Inch-Diameter-Rotary-Table
Something like this. I saw a 4 inch table with a more agreeable hold down, but if an adaptor needs be made, I am not sure how much loss of envelope or fit there will be on a larger rotary table. Anyway, the motor and encoder theoretically would bolt on where the handwheel connects.