Roskopf hairsrping removal

[gerene]

I am working on a 16”’ Roskopf pocket watch where the top pivot of the balance is broken.
I want to replace the balance staff and therefore have to remove the balance with the hairspring from the balance bridge.
The hairspring stud is not fixed to the bridge with a screw but seems to be friction fit or rivetted to the bridge.



Does anyone know how to detach the hairspring from the bridge?
I don’t want to try something that might destroy the bridge and or the hairspring.

Jan

• This topic was modified 3 years ago by Tamas Richard.

[arutha]

Hi Jan, the hairspring runs in a stud which is just friction tight into the cock. Some of them can be a bit tight to get out, I am very gentle with a fine tipped pair of pliers and I give the stud a gentle twist backwards and forwards a couple of times and then use something to push down on the stud from the top of the cock. You have to be careful not to spread the top of the stud i.e. rivetting it which will make it even harder to push through the hole. If it is very tight then you can un pin the hairspring from the stud and leave the stud in place but those tiny brass pins do love to fly from your tweezers.
Paul.

[willofiam]

Hey guys, just wondering if that is a taper pin holding the hairspring. Is there any reason not to just take out the taper pin? William

[gerene]

Thanks Paul for the advice. I thought that it would be like that, but I was not certain. Of course one can loosen the hairspring with the taper pin but I think that it might be easier to loosen the stud. As you said those taper pins are not easy to handle and one has to be careful to replace them on the same spot of the hairspring or the hairspring length will change.
William thanks for your advice as well, I am going to try what Paul mentioned and let you know how it went.

Jan

[willofiam]

Jan, just curious, what you guys are saying does make sense and may be easier. have fun, William

[gerene]

The stud came out after gently moving it with the tweezers and a light push from the top.
Thanks Paul.

Jan

[arutha]

@willofiam wrote:

Jan, just curious, what you guys are saying does make sense and may be easier. have fun, William

Hey William, in my original post It does say the hairspring is held in with a pin – @Arutha wrote:

If it is very tight then you can un pin the hairspring from the stud and leave the stud in place but those tiny brass pins do love to fly from your tweezers.

So yes, if the stud does not want to come out you can remove that iny taper pin and remove the hairspring from the stud leaving the stud still fixed in the cock. The only problem then is when it goes back together if you dont get the hairspring pinned back in the same place it will be out of beat, if it was in beat to start with!

Jan, glad you managed to get the stud out

Paul.

[gerene]

Thanks Paul.
I also managed to disassemble the balance and get the balance staff out.
However, that little finger-like projection (as Fried calls it) which substitutes the roller pin, is broken in the process . Now I have to replace that and I am not sure how to procure or make one. If someone has any ideas..

Jan

[arutha]

Jan,
if you can post up a picture and give me the diameter of the balance I might have a spare I can send you.
Paul.

[gerene]

Hi Paul,

thanks very much for your offer; Here are pictures of the broken part. Unfortunately I don’t have pictures of the part before it was broken and the broken of part seems to have vanished in thin air .

The diameter of the balance is 13.32mm

Jan

• This reply was modified 3 years ago by Tamas Richard.

[arutha]

I will take a look in my spares box and see what I can find
Paul.

[gerene]

Thanks Paul!

[arutha]

Hi Jan,
I have been real busy sorting the workshop after my move and catching up on work. I will have a look for you tomorrow
Paul.

[gerene]

I appreciate it Paul. There is no hurry at all!

Jan

[arutha]

Hi Jan,
I have had a good search through my boxes of bits and I dont have anything like that Roskopf used two types of roller from what I have found. When I did a search on google I found a PDF file all about him and it had some details on his movements. One type of roller used an oval steel pin but I think yours is the plain brass type, the bit that has broken off would have extended out and then tapered outwards to run in the fork. I think your only hope now is to track down a parts movement. Sorry I couldnt be more help.
Paul.

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