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Jacot tool and pivot file burnisher question


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Nicely done! Did motorized my pivot drilling/polishing tool after messing a bit with a bow. The bow was grabbing the piece to hard and with the electric motor i can set the pulley so soft, that if the drill is accidentally grabbing in the staff thet the pulley will slip avoiding the drill to break. Not to mention that i can use my other hand to support the file.

I see You have a nice speed-regulator. I am using a cheap PWM regulator. You should spin much faster or you will grow beard :) Does your motor have a transmission gear train? A simple DC motor would be better. 

There is also a great science behind polishing. Like how much and fast You should move the burnisher back and forth compared to the turning speed to avoid flat pinion mantle. 

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8 hours ago, szbalogh said:

Nicely done! Did motorized my pivot drilling/polishing tool after messing a bit with a bow. The bow was grabbing the piece to hard and with the electric motor i can set the pulley so soft, that if the drill is accidentally grabbing in the staff thet the pulley will slip avoiding the drill to break. Not to mention that i can use my other hand to support the file.

I see You have a nice speed-regulator. I am using a cheap PWM regulator. You should spin much faster or you will grow beard :) Does your motor have a transmission gear train? A simple DC motor would be better. 

There is also a great science behind polishing. Like how much and fast You should move the burnisher back and forth compared to the turning speed to avoid flat pinion mantle. 

Most of the cheaper DC motors that I looked at were way too fast for me. This one is geared and I can kick it up by going to 12 volts DC which better approximates my best manual speed. Don't get me wrong... there's nothing wrong with going faster. I'm just not very comfortable with it.

Thanks!

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  • 2 weeks later...
  • 2 weeks later...

I got myself a jacot tool in poor condition at a high price...

I wanted it for pivot polishing, but then I read on a blog that it is used mainly for burnish or reducing a pivot diameter (only as a last resort as it can do more harm then good) 

any advice or pet on the back?

Edited by matabog
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  • 1 month later...

if you're not making your's staffs at a lathe, or changing cracked jewels you might use it as a paper weight, like I do...

pardon the dark humor...

I suppose you want your balance staffs nice and shiny, like I did - the problem is you'll thin them down - you'll gain side shake and you'll need to change the jewels...

I'm thinking of using polishing paste on 8mm wood rod (instead of the Jacot's steel parts), but didn't get to do that yet.

 

B

 

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2 hours ago, matabog said:

congrats, then! You'll use it for what it was meant :)

You'll need a fine Mississippi stone to tackle the pivot from the top.

Mississippi stone is a new one on me.

I know about Water of Ayr stones, Arkansas stones, Tam O Shan stones, plus the many synthetic stones, but have not heard of a Mississippi stone before, is that just like a Arkansas stone?

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As i understand a Jackot tool is used with different "files" for the different needs.

For burnishing one just using a piece of flat steel with oil to avoid reducing the diameter but make the staff shiny. This method is also excellent to remove hard gum from the pivots.

To reduce the diameter one should not use grinding paste since that will also alter the tool notches. UI would use only abrasive stone or steel file. For example Degussit midget files.

 

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stone, files, burnishing tools are all used with a Jacot tool, the Jacot tool is covered in the Lathe section in the DeCarle book (Chap. 17)

I use mine all the time, but I work mainly on late 1800's to early 1900's watches, the pinions need to be polished, I believe Stephan Pahlow has a video out where he is also using a Jacot tool,

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