Feb. 20, 2021 : See the improved version of this print here:
https://www.prusaprinters.org/prints/57606-9x207x10-mt2-lathe-draw-bar-handle-for-collet-hold
Recently I purchased an ER32 collet holder for my lathes. The collet holder fits into the MT2 bore of the lathe spindle, and is threaded 1/2"-13 so that a draw bar can be used to secure it in the spindle. The draw bar is a simple rod threaded at both ends; this rod needs a handle to enable the threaded end to be tightened in the collet. This handle secures the rod in the left end of the spindle bore (see photos). It works on both my 9x20 and 7x10 lathes (although different rod lengths are needed for each lathe).
To use the handle simply add a threaded rod of appropriate length for your lathe, and secure with two 1/2"-13 nuts.
I haven't tried it, but I imagine this print could be scaled to work with metric sizes as well.
The OnShape 3D CAD file for this is available here:
Use the provided 3mf file and print with PLA.
Otherwise print large end down:
The author marked this model as their own original creation.