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Balance Staff Repair - Macgyver Style!


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Having purchased an 1888 pocket watch with a broken balance staff I brought it to my watchmaker who quoted me £120 for the repair. Being a student (and intrinsically poor) I decided to have a go at repairing it myself with less-than-appropriate tools.

The plan: Not actually fabricate an entire balance staff - but instead turn a replacement pivot, drill out the damaged one and then stick the replacement in its place...

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Lower pivot is sound, upper pivot heavily worn

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The "donor part" (pin to the right of the photo) taken from a watch that had 'seen better days'.

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Here's my VERY EXPENSIVE precision lathe, handcrafted and calibrated in the Swiss alps by select micro-engineers. (the rubber duck seen in the background is important :lookaround: )

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After - It's perfectly symmetrical IRL, (camera angles...). below it is a needle to give an idea of scale

Now I just have to machine it down to length and finish it... eep..

- Jeorge

Edited by Jeorge
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I'm intrigued by this. I do this kind of repair to clocks, but there the pivots are a lot bigger - usually 1mm diameter or greater. How do you plan to drill the hole in the staff for the new pivot?

The balance wheel is held in place by a friction-fit brass collar with the staff passing through the collar (unsure of dia. I dropped my micrometre) I'm just about to drill it now - Expect photos if it worked :P

- Jeorge

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9.jpg

(I'm aware that it's bent, and I can easily fix this)

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Ground off what remained of the previous pivot

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Yet another expensive tool to ensure that the hole will be drilled in exactly the right place (weirdly... it's the perfect height :eek:).. sadly I don't have the correct dia. drill bit to make the hole needed, and that router bit didn't even scrach it, there goes my idea... Give me a few days. :P

Edited by Jeorge
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I'm seriously impressed by your ingenuity here. You're attempting something that scares me, and I've got the right equipment to do the job!

If you are going to buy some drill bits, try and get tungsten carbide ones. I've not had any success drilling hardened steel with the HSS bits commonly available these days. TC bits are very brittle, but will drill hardened steel, no problem. The other option is to draw the temper of the staff, then re-harden afterwards. Unfortunately this would loosen the roller jewel (might also distort the balance), so the roller table and balance would have to be removed first.

Just a thought - and, like I said, I've never attempted this myself - but maybe you could make a split staff? Punch the staff out of the balance, then grind off the end of the staff so that it fits half way into the balance collar. Turn down the outside of the shank on your new pivot to a snug fit into the balance collar, cutting it to length so that it butts up against the good end of the original shaft. This way, you wouldn't have to drill any holes.

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Thank you :D

Thanks for the advice on drill bits, I was actually going to buy those HSS bits from Maplins...

I'm not fond of the idea of removing the wheel at the moment, whilst it would be ideal I just don't have the tools (or anything that resembles the tools, for that matter), Bear with me though, :D

I know it's far from perfect (granted, it still needs finishing and polishing). But if this gives the watch a new lease of life.. Well, It's perfect in my eyes :)

Jeorge

Edited by Jeorge
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I was just thinking that making a split balance might be easier. A TC bit will drill the hole for you, but getting the hole in the centre of the staff will be a real pain. If it's even slightly off centre, the balance will wobble badly, and the watch probably won't run.

When I drill a clock arbor to fit a new pivot, I use a pivot tool on my lathe. It's a very hard steel plate with countersunk holes that fits onto the cross slide. The plate is lined up with the chuck and tail stock, and holds the arbor in perfect alignment. The plate also acts as a guide for the drill bit, stopping it wandering off centre.

I once saw a chap fit a pivot about 0.4mm diameter to a French clock. He was using a watchmaker's lathe, which doesn't have a cross slide, just a tool rest. He centred the arbor by eye, and picked up a centre on the end of the arbor with a very small graver, before drilling the hole for the pivot. It can be done!

I guess that, if the drilling method doesn't work out, you could fall back on the split staff idea.

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Ah - I see. The normal method of re-pivoting involves drilling the arbor or staff and fitting a straight pin. I thought that was what you were going to do. You are actually going to drill out ALL of the staff half way down the collar, then fit your replacement shouldered part into the brass collar - yes?

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Ah - I see. The normal method of re-pivoting involves drilling the arbor or staff and fitting a straight pin. I thought that was what you were going to do. You are actually going to drill out ALL of the staff half way down the collar, then fit your replacement shouldered part into the brass collar - yes?

I actually considered doing that at first, but my father and I don't have any bits smaller than 0.75mm. I figured that we might've had one small enough (or indeed, one capable of drilling tempered steel) for the 'split staff'. No cigar!

Yup, That's exactly what I plan to do!

- Jeorge

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  • 2 weeks later...

Hi everyone,

I ordered a Tungsten Carbide drill bit to drill out the balance staff, after making all but a tiny pit in the staff it snapped off and ricocheted off the balance wheel (don't really know how, I had it in a pin vice and used light pressure) meaning it'll probably have to be poised as and when I can actually get the staff repaired. *sigh*

- Jeorge

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TC bits are very brittle. Unless you feed them in dead straight and with even pressure, they will snap. I've broken a few, even using them with my high-quality lathe.

Maybe it'd be easier to turn a complete new staff? Get a piece of blue steel, anneal it, turn it, re-harden and temper back to blue.

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Great post Jeorge. :thumbsup:

Maybe it'd be easier to turn a complete new staff? Get a piece of blue steel, anneal it, turn it, re-harden and temper back to blue.

Or find a suitable alternative from a pack of Bergeon assorted staffs...and possibly modify the balance to suit if necessary.

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Can you still buy pocket watch assortments off the shelf? The 2 things that have put me off getting into pocket watches are damaged enamel dials and broken balance staffs.

I can feel yet another branch of horological repairs beckoning to me. Fitting a replacement jewel into a pocket watch was the first repair I ever did. The jewel fitted the arbor, but the setting was a bit small for the plate. My solution - solder it in place! Not touched a PW since.

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Haha! I'm partial to using unorthodox means to repair, however I'm not too sure about the whole soldering thing, whatever makes things work, I suppose ;)

I did read somewhere that someone had made/procured off-the-shelf parts for old english Pocket watches. but my searches have been fruitless so far. Heck, I can't even find a colleted hairspring anywhere :(. I have tried to swap parts out, even buying an old fusee movement (without barrel and chain) but sadly the staff was a fraction too short. Arrgh!

EDIT: Hmm, Interesting. The picture shows that the movement has that click for the fusee cone, as evidenced by the silvery pivot in the appropriate 'hole'. However when I took delivery of it, it had only the spring.. Odd.

I can still use this balance though, I just need to drill out the staff, I might even resort to using alum. Eek.

- Jeorge

Edited by Jeorge
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Great post Jeorge. :thumbsup:

Maybe it'd be easier to turn a complete new staff? Get a piece of blue steel, anneal it, turn it, re-harden and temper back to blue.

Or find a suitable alternative from a pack of Bergeon assorted staffs...and possibly modify the balance to suit if necessary.

Ooh! I didn't notice your post, it would admittedly, be a much easier option if I had a staking tool, sadly I don't - and I can't really justify the price (It'd be much cheaper giving it to my watchmaker, I plan on making repairations if this plan works - In the form of a new watch, which is a much preferred route, IMHO :P)

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Ooh! I didn't notice your post, it would admittedly, be a much easier option if I had a staking tool, sadly I don't - and I can't really justify the price (It'd be much cheaper giving it to my watchmaker

Is that true? :huh:

You can probably pick up a good second hand staking set for around £40. I can't see how any professional watchmaker could justify messing around with changing balance staffs for that sort of money. These days, you'd just buy a new balance assembly. I think changing (or making) balance staffs is only for the enthusiasts amongst us or is only carried out on valuable watches (sentimental or monetary).

Or you have a friendly watchmaker who doesn't charge by the hour.

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  • 3 weeks later...

My balance staffs arrived today!

I've also managed to remove the Balance wheel and roller table, and in true 'Jeorge fashion' I did it with unfitting tools - A claw hammer, screwdriver and decommissioned going barrel in lieu of an appropriate staking tool. :D

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Note the old staff with a now-mangled pivot and its replacement, ready for turning. (I expected the original to be a bit more... elaborate, I could've turned one out of a sewing needle otherwise...)Also note the marred balance arm, Gah, stupid drill bit.

- Jeorge

Edited by Jeorge
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I like your style Jeorge....a bit like mine in 'The Grandfather Clock' project. I'm sure your ingenious mind will come up with a solution....sometimes you have to think 'outside the box'. Keep posting your progress and pics. From the support I've had in my project, there are plenty of interested members out there. Good luck! :good:

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  • 3 weeks later...

pa030183-3.jpg

(Original at top)

Nothing too groundbreaking - But my first staff! (A shade too large, and perhaps a bit rough).. I should really invest in a Micrometer - I'm hoping to turn something the correct size this weekend.. Eep.

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