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Not sure if anyone has had difficulty working on bent hairsprings but I thought I should share my idea...

My problem is with the Bergeon 30105 tool - I've found that the hole for the collet (3.5 or 4.5mm) is too large and that it doesn't allow the hairspring to lay flat on the glass with the stud attached. Plus, it's way too expensive for what it is (I'm a big fan of their tools normally)!

I've drilled a few hole in an old petri dish and I think I'm close to making a tool that is better suited to wristwatches, the balance in the photo is from a Landeron 48.

The holes are a bit rough on the underside of the glass but it doesn't affect the hairspring which lies flat on the surface.

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Forgot to mention that with the extra hole for the stud, you can work on the spring from either side.

I used a 1mm diamond core drill bit (Eternal Tools) for the initial hole and then a Dremel 7134 diamond bit to widen the holes.

Both bits are about £7 so still a lot cheaper than the Bergeon tool.

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2 minutes ago, watchweasol said:

Good idea, the same could be done using clear. plexiglas or thick polycarbonate, easier to drill than glass.

Won't there be some 'give' even with hard plastics? The glass is surprisingly easy to drill through. It just needed water to cool it down. I just used a Dremel with a not very sturdy pillar drill attachment.

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Intrigued...but I have only tried to bend one hairspring and it was just a slight adjustment. 

So the idea behind the bergeon and your tool is simply to have a hole for the stud so that the hairspring can lie flat?  Why does it need to be clear?  Why is flexing an issue because I cannot imagine any pressure on the plate since you are tweaking a hairspring with the finest amount of force. 

Anxious to understand this!

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Hi My understanding is this, clarity of the base over a white card enhances the definition of the spring, flexation I would have thought was not a problem on a solid base. I have done this with just a thick white card but the idea of the drilled dish is sound as its weight wiill make it stable and not prone to moving as you work.

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12 hours ago, LittleWatchShop said:

Intrigued...but I have only tried to bend one hairspring and it was just a slight adjustment. 

So the idea behind the bergeon and your tool is simply to have a hole for the stud so that the hairspring can lie flat?  Why does it need to be clear?  Why is flexing an issue because I cannot imagine any pressure on the plate since you are tweaking a hairspring with the finest amount of force. 

Anxious to understand this!

Getting the hairspring round is tricky but keeping it flat at the same time is even more of a pain. 

My problem with the Bergeon tool is that the hole is way too large for a wristwatch collet so the hairspring just droops at it's centre. Also, with no hollow for the stud, the spring itself isn't lying properly flat. With the extra hole for the stud, the spring can now be adjusted from either side. 

I think the glass is for clarity and stability as watchweasel explains above... I have to use a microscope when trying to adjust a hairspring, the glass (or very clear plastic) gives an unhindered image of the hairspring. 

I have one shot of correcting a Valjoux 92 hairspring or having to adapt another balance and hairspring to fit... either way I need all the help I can get! 

I'm also trying to adapt some old tweezers to have right angled tips so I can properly see what I'm adjusting when using the microscope. 

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  • 4 weeks later...
On 6/12/2021 at 8:07 PM, LittleWatchShop said:

Intrigued...but I have only tried to bend one hairspring and it was just a slight adjustment. 

So the idea behind the bergeon and your tool is simply to have a hole for the stud so that the hairspring can lie flat?  Why does it need to be clear?  Why is flexing an issue because I cannot imagine any pressure on the plate since you are tweaking a hairspring with the finest amount of force. 

Anxious to understand this!

I think the reason is to reduce friction between the surface and the hairspring+tweezers? I worked on my first hairspring on a matt and the feedback sensation from my tweezers was not great as it rubs the surface. I imagine glass would feel so much better.

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The reason there is only one hole in the tool from the beginning is because when getting the hairspring in shape you work on it without the stud on it. Taking the stud away gives you greater control to work on the hairspring and gives you a better chance to get it really flat and nice.
The glass/plastic surface makes it easier to rotate it while working. Having a white paper underneath gives you a better contrast so you can see how the hairspring should be turned/bent. With the stud still in I think makes it harder to get a perfect shape on the hairspring.

If you are afraid of losing the stud when you take it away you always could invest in an assortment of them (to the right in the picture).

 

Hairspring.png

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22 hours ago, HSL said:

The reason there is only one hole in the tool from the beginning is because when getting the hairspring in shape you work on it without the stud on it.

Still quite a large hole though, 3.5mm or 4.5mm for the Bergeon tool. Surprised they haven't made a smaller version.

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