Metal Lathe Cut Off Tool holder - NEW easy to make design

[metric_taper]

Thread fit on a backing plate is important but it can be fairly loose and still be accurate. Same with the none threaded portion (pilot?). It can be several thousandths over size and the chuck will still be concentric as long as it seats good on the back register. The V shape of the threads centers the chuck. The chuck I bought is a very cheap (about $100) Chinese made chuck and it is incredibly well made (I'm still in shock).

I think what I'm calling a pilot, is the same as your register. My threaded spindle lathe has the clearance between the chuck, which has the recess bore to fit the spindle register is about 1 thou.

Yes, I had to make a new quill for the tailstock that I could mount a new female acme thread component I purchased from MSC along with the precision lead screw.
And I machined the MT2 hole to have the tang holder.

The cylinder between the power feed and the original tail stock was for a longer quill, as the original travel was less then 3 inches. I seem to do deep boring on most of the repairs around my shop. The crank came from a scrap piece of brass I had in the shop. The original crank, got damaged, when I accidentally pushed the tail stock off the end of the lathe, when putting in a long part between centers. This repair was what resulted in the power feed being added. There's still some projects to finish this, like improving the power feed feed stop switch. I would also like to mount a DRO on this for measuring the depth of a drilled hole.