So you want to make a hairspring….

[tmac1956]

All:

I once entertained the thought… but then I woke up sane.

Here’s what it takes to make one.

https://www.youtube.com/watch?v=X1_Jh81-Q4Y

Enjoy!
Tom

[david pierce]

Tom,
Rolex has a Youtube video showing their hairspring manufacturing operation. I have no idea what their machine cost but it is certainly beyond the budget of most other watch factories. I wonder where a small operation like Roger Smith buys his hairsprings. The research on the metallurgy alone would be beyond the budget of most watch factories.
david

[arutha]

The way they used to make hairsprings(Blued steel), and how they taught it in the swiss watch school wasn’t too difficult. Three or four lengths of hairspring wire(depending on how big you wanted the spaces between the spring coils) were wound into a purpose made device(A little bit like a pocket watch mainspring winder), and then heated until blue, then quenched. I have yet to see one of these tools come up for sale and even if I could find one I have no idea where to buy the flat wire.
Paul.

[tmac1956]

Paul:

I have enough information on the winding tool to build one. Like you, however, I have no idea where to find the material. I suppose if you bought $10,000 worth at the time, you could find it.

Later,
Tom

[tmac1956]

Paul:

I have enough information on the winding tool to build one. Like you, however, I have no idea where to find the material. I suppose if you bought $10,000 worth at the time, you could find it.

Later,
Tom

[david pierce]

Tom,
The problem with the blue tempered steel is it turns your balance wheel into a thermometer. This presents a problem maintaining equal time over a temperature range. This was the reason, as you already know, for the split bimetal compensating balance wheel. The modern hairspring metals did away with the need for the split balance wheel and watches made with modern manufacturing techniques now use a solid monometalic wheel. If you notice the underside of a modern balance wheel you will see little holes drilled on one side of the rim. This is because the wheels are now dynamically balanced and the holes are the removed metal on the heavy side of the wheel. This is a better manufacturing process as it produces a more stable and in balance wheel, but would be finanically out of reach for a company making a small quantity of wheels. This is why some of the small low production shops still use wheels with balance screws. This, of course, flys in the face of observation when one looks at a master watchmaker selling only a few watches a year for $100,000 and up per watch. When the customer looks at all of the timing screws on the balance they feel that they are looking at the very finest quality available today.
david

[tmac1956]

david:

That’s interesting. I’ve seen monometal balance wheels with horizontal weights, but the creator’s name escapes me. It sure seems like a better solution as does the one that you descibed. I suppose we are just looking at old technology thinking there have been no recent advancements when — just as in every area – there most certainly has.

Thanks,
Tom

[david pierce]

Tom,
I that is a Rolex balance wheel. I believe, all things being equal, that simpler is better. Occam’s Razor applies to balance wheels as well.
david

[tmac1956]

Hey:

If you could find one of a small enough diameter, then I wonder if guitar string might work? The smallest I’ve found is 0.006 inches. If they make one small enough, then I suspect they would have to be rolled flat as well… perhaps something like this would work…

http://www.ebay.com/itm/400666990640?_trksid=p2055120.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I’m just playin’ around with the idea again.

Later,
Tom

[tmac1956]

All:

Just to follow up… I found some tiny strings used on an octave guitar. I’m waiting on the diameters to see how small they actually are.

Thanks,
Tom

Update… The wire will need to be about 0.0018″ in diameter so I know these will be way bigger. They would need to be drawn down to size. However:

“If it [the hairspring] is off by a mere 0.1 microns, the resulting escapement can deviate by up to three minutes a day.”

http://www.watchesbysjx.com/2010/11/manufacture-of-hairsprings-at-lange.html

Man… 1 micron? Oh well.
Tom

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