Lathe Pivot Polisher

term789

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Oct 19, 2016
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HI I am interested in seeing what you guys use to polish pivots on your lathes?
Do you use a tailstock collet holder or something else?
Pictures would be great.
Thank You
 

rstl99

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Oct 31, 2015
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Not sure if you mean watch or clock pivots, but for clock pivot polishing you can also file a piece of brass stock inserted in the lathe's tailstock and turn the pivot into the slot while polishing or burnishing it from above. A clock course instructor said you can also make such runners using a piece of wood dowel, which is cheap to do and replace (he said the brass runner could accumulate bits of steel which could scratch future pivots polished in the runner).

IMG_0021.JPG IMG_0022.JPG
 

Harry Hopkins

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Nov 16, 2011
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A clock course instructor said you can also make such runners using a piece of wood dowel, which is cheap to do and replace (he said the brass runner could accumulate bits of steel which could scratch future pivots polished in the runner).
I make my runners with the hole sized to the arbor instead of the pivot so the runner supports the arbor and the pivot is not touching the brass and will not get scratched by dust and bits of steel that accumulates in the runner.

20171123_150605.jpg
 

rstl99

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I make my runners with the hole sized to the arbor instead of the pivot so the runner supports the arbor and the pivot is not touching the brass and will not get scratched by dust and bits of steel that accumulates in the runner.

View attachment 364223
Good approach, Harry. makes sense.
 

Dushan Grujich

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Jun 20, 2003
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Not sure if you mean watch or clock pivots, but for clock pivot polishing you can also file a piece of brass stock inserted in the lathe's tailstock and turn the pivot into the slot while polishing or burnishing it from above. A clock course instructor said you can also make such runners using a piece of wood dowel, which is cheap to do and replace (he said the brass runner could accumulate bits of steel which could scratch future pivots polished in the runner).
G'Day Robert!

It really makes no difference. For pivot burnishing both Jacot lathe runner as well as Jacot drum for mounting in the tailstock of the lathe are made of glass hard steel. They both are designed in such a way that only a tiny part of the pivot is exposed to burnisher and thus possibility of ending with tapered pivot is avoided.

Have a look click here, for an explanation.

One should know difference between burnishing and polishing. Burnishing provides strengthened pivot surface, it is a kind of case hardening, where polishing just makes pivot shiny, essentially useless and unable to withstand wear.

Burnishing is work hardening process and the pressure applied to pivot is substantial, the pivot must be supported quite well, a piece of hardwood is flimsy, providing neither the support required for burnishing nor it has the form that will prevent tapering the pivot, be it watch or clock sized.

Look-alike is just a look-alike, not the real thing - hence, if one wants to do the job properly one should use the real thing,

Cheers

Dushan
 

gmorse

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Jan 7, 2011
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Hi Robert,

...Burnishing is work hardening process and the pressure applied to pivot is substantial, the pivot must be supported quite well, a piece of hardwood is flimsy, providing neither the support required for burnishing nor it has the form that will prevent tapering the pivot, be it watch or clock sized...
This is also why supporting the arbor rather than the pivot is unsafe, especially in smaller pivots and those which are left hard, as many French clocks are.

Regards,

Graham
 

term789

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Oct 19, 2016
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It is for clock pivots.
Seems like a Jacot-drum would be ideal but hard to find.
If you use the brass stock in the tailstock method, what do you use to support the brass pivot polisher?
 

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