I made this handwheel to make it easy to turn short threads up to a shoulder on my lathe. The Handwheel simply slips into the headstock on tightens up with an expanding arbor as shown. I find it most useful for very short threads and very convenient in allowing you to stop threading in the exact same spot each time. If you have a gearhead lathe besure to select a higher speed which will reduce the effort you need to exert to turn the crank ;-)
The handwheel itself was salvaged from an old piece of machinery and I simply made a suitable expanding arbor so it could perform its new function.