lantern chuck for holding sprockets

[Frank S]

I had a number of #35B-8 sprockets that I needed to shorten the length of the hub.
Anyone who has ever tried to chuck a sprocket by any other means than on the hub of through the bore knows this is difficult at best especially if the tooth count is not divisible by 3 for chucking in a 3 jaw additionally tooth damage is a primary concern on the smaller pitch sprockets such as the 3/8" pitch #35.
To solve my problem, I found that the sprocket fit nicely in the cap of a -16 37° JIC hydraulic fitting.

Selecting a Male adapter and cap I first tightened the cap on the fitting then chucked it in the lathe and turned the threads off the opposite end

Then reversed the assembly and bored a hole the diameter of the hub through the cap

Then I faced the 37° angle off the face of the fitting

then tightened the cap on the now arbor with the sprocket inside an added bonus was the teeth of the sprocket are ground to a slight angle helping to align it for concentricy inside of the cap

From then on it was just a matter of facing off the amount of length I required facing the cap along with the sprocket to serve as a gage for the final length.

Not quite enough

no problem just re chuck and face a little more off

Rinse and repeat as many times as needed