For the long-running traction engine project, I needed a way to index the wheel rims for laying out both the strakes and the spokes.
So, a cheap and cheerful headstock indexer seemed like a good idea, as my dividing head is designed to fit Taig equipment
which is a little too small for the wheel rims in question.
Sawed off a hunk of left over angle from the "this will be useful one day" pile and cut away everything that didn't look like a bracket
for a spring-loaded plunger

Some straight forward turning, drilling and tapping and a conveniently sized spring from the junk box and we have a plunger assembly

Turning an extension spindle to hold any of the lathe's change gears (this photo is really only here to show off my absolutely
favorite tap handle, an Eclipse Number 142 that is probably older than I am)

That spindle screws into the one on the right that locks inside the spindle of the lathe
(don't recall what this type of locking system is called, just remembered it from putting handlebars back on bicycles' headstocks in my teen-age years)

And here it is all assembled, the plunger Ass'y slides up and down on the bracket to conform to different sized gears as required,
the bracket only required two holes in the cheap sheet steel cover, the extension spindle lets the whole thing work without requiring any other mods to the cover..

and here's a wheel rim with the needed layout marks

could be prettier, but it works fine. Might even give it a lick of paint one day

(or even get out the ball turner and make a knob for it....)
Cheers, Joe