Worn non jewel pivot holes

[Danh]

Hi Guys

looking to see if anyone has any advice or any ways of dealing with worn pivot holes. 

Working on a 1885 Kendal & Dent pocket watch, I am fairly certain that pivot hole size relating in lateral play in the train wheels is causing the movement to stop after the main power has started to release from the main spring

Any words of wisdom greatly appreciated

 

thanks

 

[StuartBaker104]

The correct way to fix this is to broach out the pivot hole, fit a bush then re-establish the hole and oil sink. You will also need to refinish the pivot by filing and burnishing on a jacot tool.

You will most likely find guidance on the net by searching for clock pivot bushing. I know there are better links if you look hard, but here is a quick summary http://www.m-p.co.uk/muk/ryoc/doc_page16.shtml

I know that some would fit a jewel as it’s quicker and easier, and some would try and punch the edges of the hole to close it up. Neither would be my recommended option!

[Danh]

1 hour ago, StuartBaker104 said:

The correct way to fix this is to broach out the pivot hole, fit a bush then re-establish the hole and oil sink. You will also need to refinish the pivot by filing and burnishing on a jacot tool.

You will most likely find guidance on the net by searching for clock pivot bushing. I know there are better links if you look hard, but here is a quick summary http://www.m-p.co.uk/muk/ryoc/doc_page16.shtml

I know that some would fit a jewel as it’s quicker and easier, and some would try and punch the edges of the hole to close it up. Neither would be my recommended option!

Thank you Stuart - most helpful indeed

[digginstony]

In the day, to fit a Bushing or to close the hole with a staking set and broach out both had there advocates, with this type of movement.
Both methods lend themselves to an effective repair, obviously the latter being of far less cost.

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[measuretwice]

isn't it an issue locating the hole properly?  In that the above locates based on the existing hole, but if its worn its a bit elongated so its centre location, that a tool will follow, has changed slightly?

Edited April 3, 2018 by measuretwice

[digginstony]

isn't it an issue locating the hole properly?  In that the above locates based on the existing hole, but if its worn its a bit elongated so its centre location, that a tool will follow, has changed slightly?

That's why you have to close the hole to less than the diameter of the pivot and broach out, keeping the hole as round as possible. This work is not fine horology. As Oldhippy would say " Its more like Blacksmithing. "
But you can also misalign when Bushing, requires a bit of practice.

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[BUSAKAZ]

isn't it an issue locating the hole properly?  In that the above locates based on the existing hole, but if its worn its a bit elongated so its centre location, that a tool will follow, has changed slightly?

The way to do it is by the means of a D cutter, if the hole has been elongated there will be half of the hole that has been untouched that is where you line up the cutter so the flat side of the cutter is facing the elongated part of the hole then the cutter will be centred correctly if you know what I mean that’s why the cutters like in a jeweling set have a flat face.


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[Danh]

This is a great topic - thank you all

[digginstony]

Apologies. On the latter method as mentioned I should of said ream out not broach, that's a bit misleading. Also advisable to use a Reamer when setting a new Bushing, rather than a drill bit. The chances of misalignment are greatly reduced.

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[BUSAKAZ]

Apologies. On the latter method as mentioned I should of said ream out not broach, that's a bit misleading. Also advisable to use a Reamer when setting a new Bushing, rather than a drill bit. The chances of misalignment are greatly reduced.

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Only animals use a drill bit, there certain tools for doing certain jobs.


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[BUSAKAZ]

Hi Guys
looking to see if anyone has any advice or any ways of dealing with worn pivot holes. 
Working on a 1885 Kendal & Dent pocket watch, I am fairly certain that pivot hole size relating in lateral play in the train wheels is causing the movement to stop after the main power has started to release from the main spring
Any words of wisdom greatly appreciated
 
thanks
 

What you need is this lot









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[Danh]

1 hour ago, BUSAKAZ said:

What you need is this lot









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That would do it