Not having a captive drawbar, I removed the nut (LH thread) retaining the pulley to the spindle. Turned back the under side, to form a register . Bolted a plate with two tapped holes further out, on opposite sides.
Fit to machine so that the plate is seated on the register on the underside of the nut.
Made up a plate with two clearance holes to match the spacing of the tapped holes, but with a central tapped hole.
M6 should suffice, I used 1/4 BSF threads, in 3mm plate
When it comes time to change the tool: Slacken drawbar by a turn or so, attach upper plate with two bolts, tighten central forcing screw. Taper usually separates, without need to thump the bearings on the quill. If it doesn't, a light tap on the tight forcing screw does the trick.
Howard