Jump to content

Balance staff: is this a decent quality?


Recommended Posts

I‘m going to replace the balance staff of a Russian pocket watch (Molnia 3602). Because it is the first time I purchase a balance staff as a spare part I am not sure about the finishing quality to be expected. Here are some pictures from what I got (ebay, „NOS“). Is this a decent quality for such an item or is it chunk? Your educated comments are highly appreciated.

IMG_8382.jpeg.d4c511f608ce17f8767d40b7de3fabdb.jpeg

IMG_8378.jpeg.0b5ffe5d375e9f2544671e99abfa8d95.jpeg

 

Edited by Kalanag
Link to comment
Share on other sites

  • Kalanag changed the title to Balance staff: is this a decent quality?
2 hours ago, Kalanag said:

I‘m going to replace the balance staff of a Russian pocket watch (Molnia 3602). Because it is the first time I purchase a balance staff as a spare part I am not sure about the finishing quality to be expected. Here are some pictures from what I got (ebay, „NOS“). Is this a decent quality for such an item or is it chunk? Your educated comments are highly appreciated.

IMG_8382.jpeg.d4c511f608ce17f8767d40b7de3fabdb.jpeg

IMG_8378.jpeg.0b5ffe5d375e9f2544671e99abfa8d95.jpeg

 

The hub looks a bit rough and the pivot doesn't seem particularly polished but that might just be because the photographer seems to have taken the picture with a potato 🥔😉 . The rivet still looks like it has its shape though.

  • Like 1
Link to comment
Share on other sites

  • 1 month later...
On 12/16/2023 at 5:02 PM, CYCLOPS said:

you should be able to use after clean-up in lathe as long as the hub fits the balance wheel.....

Meanwhile I found some time to investigate the dimensions of the new staff.

- The pivots fit the jewel holes

- The end shake is fine

- The wheel hub fits the wheel diameter

BUT

- The double roller ID is 0,2mm smaller than the staff‘s OD (0,4 vs. 0,6mm) 🤨

Not having a lathe, what would you folks do?

Edited by Kalanag
Link to comment
Share on other sites

10 minutes ago, Kalanag said:

Meanwhile I found some time to investigate the dimensions of the new staff.

- The pivots fit the jewel holes

- The end shake is fine

- The wheel hub fits the wheel diameter

BUT

- The double roller ID is 0,2mm smaller than the staff‘s OD (0,4 vs. 0,6mm) 🤨

Not having a lathe, what would you folks do?

Jacot ?

Link to comment
Share on other sites

5 hours ago, Kalanag said:

I should have mentioned that I don‘t have a Jacot tool.

Ronda catalog is showing the roller table diameter on staff as 56 maybe roller is too small . Could you measure on a reamer where you need to be with the size ? Stop short and finish with  a smoothing broach.  Reducing the staff would feel safer for me and normally easier to replace if things go wrong . 

  • Like 1
Link to comment
Share on other sites

3 minutes ago, Kalanag said:

Well, there seems to be no other option than purchasing a reamer that I will never need again. I‘m not happy with this idea (yet).

Can a cutting broach do the job?

Well I’ll throw tuppence in the pot, the knowledgeable folks will hopefully chime in. A cutting broach is basically a reamer with a taper, I would think this would be what you would want for this but I may be wrong. A reamer is parallel and would be more for making a true hole. Saying that I think there are also tapered reamers kicking about for things like morse tapers.

 

Tom

  • Like 1
Link to comment
Share on other sites

1 hour ago, Kalanag said:

Well, there seems to be no other option than purchasing a reamer that I will never need again. I‘m not happy with this idea (yet).

Can a cutting broach do the job?

I think that is what nev was meaning, reamer just being another term. I wouldn't be too happy either. 

  • Like 1
Link to comment
Share on other sites

2 hours ago, Kalanag said:

Well, there seems to be no other option than purchasing a reamer that I will never need again. I‘m not happy with this idea (yet).

Can a cutting broach do the job?

Do you have smoothing broaches that you can mark up the diameter on, so you have a gauge to work to. I do this when opening up a barrel hole so i know when to stop.

4 minutes ago, nevenbekriev said:

Yes, my english doesn't make difference between reamer and cutting broach. I try to improve it here...

Its ok nev those 2 terms are more or less interchangeable where ever you come from.  Reamers are often associated with their use in jewelling tools but some people also do call them broaches . Broaching and reaming mean the same, to open up a hole. Broaching a subject would be to open up a discussion usually a difficult one.

  • Like 1
Link to comment
Share on other sites

the roller or staff needs to have some taper to fit tight, you will use tapered reamers again and again in the future I'm sure, I don't know how you will hold the roller to do this maybe a pinvise.....be careful not to remove too much and hopefully the hole will not get out of round

  • Like 1
Link to comment
Share on other sites

Got this set of carb jet broaches (0,4 - 1,6mm) for just €9,- (shipping included). They worked well for the cutting. After finishing with a smoothing broach the result is fine 🙂

IMG_8721.thumb.jpeg.1eb1eca383c4b786ee810ff3b226bf09.jpeg

Edited by Kalanag
  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • The Chaika 1601A bridge styles look more like something from an earlier time. It is also finished relatively well for the 1980s, as a lot of manufacturers by then had started a race to the bottom in terms of finishing and materials as a result of the quartz crisis. If you compare it with a comparable Swiss movement from the same period, you will find they have much less elaborate bridges, and other cost cutting measures. Straight cut bridges with no bevel on the edges are much cheaper and simpler to produce than the curved bridges of the Chaika 1601A. They even went to the trouble of stamping a serial number on the movement. A practice which only the higher end Swiss manufacturers were bothering with by this point. The Chaika 1601A does have a relatively cheap balance though. The 'timing screws' in the balance are for decoration only. Having said all that, the USSR caliber designs were fairly conservative, and produced for relatively long periods. This was partly as a result of the command economy, which tended to lead to relatively little innovation in design, and partly because they weren't chasing after the fickle flights of fashion that arguably drove some of the changes from other manufacturers. Some of the USSR designs were licensed or even "borrowed" from Swiss and French designs.   For example I have a Sekonda pocket watch (which may be the next one on the bench for a clean and service). It has a Chelyabinsk Watch Factory "Molnija" 3602 caliber in it, which was based on a Cortébert movement used in Swiss watches from around 1940. Here is one of the examples from Ranfft. You can see that it is similar to the Chailka with curved bridges. They even had Breguet over coil hairsprings and "Geneva" striping. Some had shock protection, some did not.   The Sekonda is in its original 1980s plastic presentation box, complete with "manufacturers guarantee" (although Sekonda obviously didn't manufacture it). This same Molnija  movement was produced in the Chelyabinsk Watch Factory with little change, except notably in the level of finishing, from around 1947 until the early 2000s when production ceased. For comparison, here is a Swiss ST96 from around the same period. Smaller jewels, flat and unrefined finishing, and all in all, a little bit lacklustre. .. and a Rolex 600 from around 1922   The Chaika, despite being from the 1980s, to my eye at least, looks a little closer to the Rolex than the ST96
    • Elaborate on this statement. What sorts of things define calibers from different decades? The only thing I can think of short of the pocket to wrist watch shift around WWI and quartz is shock settings starting... late-40s, early-50s?
    • I'm not sure who "we" is as I'm not a part of how "we" do it. Most of "us" develop their own method(s). Please re-read what has been said;  
    • Nice one Andy- a very ‘blingy’ 404 with all those jewels…
    • It's a matter of preference really. You should keep the #5 aside and just use them for fine hairspring work though; otherwise they will end up damaged and be useless for that. Some like #1, some #2, some #3 for general work. Some use brass or nickel tweezers for general work- this is good as they are less likely to scratch delicate parts, and are much "grippier". On that note, the finer the tweezer, the more likely it will be to want to launch parts.   I have a bunch of nickel tweezers that have been retouched so many times they are like 30% shorter than new. Those become handy for when you need very strong tweezers- just used a pair to unscrew the bond from inside a floating barrel. My general use tweezers the last few years are a couple of pair of #5 that have been sharpened enough times that the ends are now very strong; useless for hairspring work, great for general work. These are Dumont Dumostar, which is a much more tough alloy than the Dumoxel, and less brittle than their carbon steel ones.
×
×
  • Create New...