This is one of those very handy tools you eventually use all the time, and it's very simple to make:
I cobbled this tool together from items I had on hand, most of which is scrap I've salvaged from here n there so cost me time only, which wasn't very long.
I considered a press fit for the bearings but decided to bolt them in place as it to give it more flexibility, I'm fixing up a mill I got recently and it can also be used as an edge finder.
Job was simple, face, turn to size, drill, tap (M6 x 15), champfer, flip round, trim to length, repeat first four steps.
In this case though, it was a bit large for my small quick change toopost holder:
It held it very tightly though, so left it where it was and tried something new by doing a bit of light milling on the lathe. A 10mm two flute stub end mill took care of the cutting and just judged the cut depth by feel and eye, which went well all considered:
I then cleaned up the edges? flipped it round and it was a perfect fit:
For those that don't know how this kind of tool works on a lathe, here is a short demonstration video I made:
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