Screw-on chuck mounting to bayonet.

[Toolmaker51]

FYI I've been looking to make an adapter to allow my D1-4 chucks to be mounted on a rotary table. One of the first thing I noticed was that 7 1/8 degree taper. I suppose it is well know by all here, but I found that tan(7 1/8 deg) ~ 1/8 which greatly simplifies the necessary calculations.

If I was to apply D1 chuck to a rotary table, I'd make a large enough diameter for common strap clamps or plain studs, with a short boss on the back side for the table bore. Morse taper is common place. Loose or close fit will simplify dialing in, recommend against slip fit.

Alternately, a suitable bore on the locating table if you intend leaving the pins in place. I foresee difficulty removing chuck against gravity, compared with hanging on a spindle.