This is a rather specialized jig, but maybe someone else can get some use out of it.  It's designed to fit into a hole drilled with a hole saw or similar tool, and secure a wooden dowel, metal rod or pipe, or similar smooth, cylindrical object at an adjustable height.  With a pointed dowel this can be used to establish a fixed point for point-to-point drilling on the drill press, and perhaps could be used as a dead center for light lathe-like work (for example sanding), if you're careful to keep your hands clear and not apply much lateral pressure.  It could also be used to securely mount an adjustable rod in another surface.

The .stl files are built for 0.5 inch dowels (with 0.3mm of clearance to compensate for print errors and make sliding a dowel in easier), to fit the hole in the center of my drill press table, and a 1 inch wide, at least 20mm deep hole to mount the chuck in.  However, the .step file is parametric and can be configured for any size dowel or rod, so long as it's substantially over 1mm (that being the fixed gap between the chuck jaws), and any length and diameter chuck and shaft.  You could even make the shaft much wider for a surface mount.  The thread coarseness is also configurable; 1.5mm works well on my printer, but you may want to go bigger.  Note that you'll need to adjust the number of thread revolutions for chuck height and thread coarseness (but not for dowel diameter).

Printed with 30% grid infill in PLA.  No need for supports, but you may have bed adhesion issues without a brim.  You'll get better adhesion on the chuck ring if you print it standing upright; that is, with the wide end of the tapered threads downward.