Re-Pivoting

[chris mabbott]

To date, I have only attempted to re-pivot once, I didn’t fare too well

I have one of those little pivot machines with the index-able rotating head, but my problem is finding drill bits to fit into the plunger and through the guide hole in the index head.
Now I have some incomplete, but still quite good sets of pivot drill bits, my problem is that they wont fit into the machine, dia is too large, even though these things are tiny..
I’m also missing the fly wheel on this, but I’m unsure about how to make a new one to fit the smaller diameter shaft, yet fit over the larger end

Any suggestions would be appreciated..

[daryn]

Does the end of the shaft pull off ?

[willofiam]

Or is the pulley supposed to be on the larger portion? William

[daryn]

Or the pulley could be in two halves that screw together???

[chris mabbott]

Hey guys, Eh, I don’t know 😆 Daryn, I’ll check that. William, others I’ve seen have the pulley on the narrow part, but who knows with these things?

[Bob Tascione]

Hi Chris,
Might be easier to make a new holder that will accept the normal shank size of the drills you have.
As for the pulley…I would have to ask the same questions that Daryn asked. Is the end pressed on or does something unscrew? If or somehow pull apart? If not then could the pulley have been split or made up of two pieces?
Enjoy,
Bob

[david pierce]

Chris,
There is an inexpensive book available called THE ART OF REPOVITING FOR THE WATCH AND CLOCKMAKER by Robert D. Porter, CMW. The book shows how to make pivot drills on a watchmaker lathe. I bought a copy off of Ebay a few years ago and was very impressesed with his innovative solutions to the problem. He takes a pin vice and drills a hole through the shaft that fits over a stud mounted in the tool post holder. then a grinding wheel is put in the lathe and the pin vice fixtures the drill blank. With this crude setup he was able to grind a reasonably accurate drill bit. If you hunt for it on Ebay you can probably find a copy. It is well worth the price.
david

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