Balance staffs, thecsame but not.

[Neverenoughwatches]

Hi all watch people, I'm just searching through some of my stock for a balance staff for a repair. The one i need for an FHF 26 ordinary i don't have, it would also fit a few other calibers of which the 26 is the base model. I have the staff for an inca shock model but that leaves the pivots 1/100  short on each end and the hub is 2/100 lower. Now looking through a Ronda catalog I've found a match for the 5 staff sizes documented. This staff which i do have is for a benrus O, here's the but, the Ronda list number is different. These 5 sizes also tally up with what balancestaff.com have on their website, which is really no surprise as their list must come from Ronda anyway. Something else thats a little odd the Benrus O is actually an FHF 1146 model listed in Bestfit, and again heres the but this is a different Ronda number again actually 4 different Ronda numbers for 4 different movements each of a different  size. Confused you will be, i am anyway, but a lot of this is besides the point.  So i have an FHF 26 ord. whose staff measurements apparently match the staff of a Benrus O which i have but their Ronda numbers are different. How close can they be ? Given that the 5 dimensions that are available are exactly the same. Could something be different ? as the 5 measurements do not tell a full profile of the staff and if so why are the Ronda numbers not the same. Yes i could just try to fit the staff and see what happens which i will probably end up doing, but i just thought it made an interesting question and might apply to making a staff from scratch with a drawing ( do you need more than the 5 sizes ?  and is it a case of improvising as you fit it ? And before anyone asks some nugget sold me a watch that had a balance with no staff in it so i cant pair them up. If anyone has any sort of answer to this seemingly ridiculous question then I'm Noddy's best buddy .      Thanks fellas

[JohnR725]

10 hours ago, Neverenoughwatches said:

scratch with a drawing ( do you need more than the 5 sizes

If you're making a staff to fit you don't need any dimensions or drawings. That's because you'd make everything to fit.

Dimensions how many do you need? I have way more pocket watch stuff unfortunately for instance in one of the books I have a list balance staffs by size and there's with their suggestion of the numbers are quantity you need

 

But in the back of the book they have drawings of Waltham no idea where they came from and Howard watch company as you can see technical drawings have way more dimensions.

 

 

 

 

 

 

[Neverenoughwatches]

35 minutes ago, JohnR725 said:

If you're making a staff to fit you don't need any dimensions or drawings. That's because you'd make everything to fit.

Dimensions how many do you need? I have way more pocket watch stuff unfortunately for instance in one of the books I have a list balance staffs by size and there's with their suggestion of the numbers are quantity you need

 

But in the back of the book they have drawings of Waltham no idea where they came from and Howard watch company as you can see technical drawings have way more dimensions.



 

 

 

 

 

 

Thanks John the Waltham drawing was kind of what i was thinking, maybe its insignificant to a point but things like the taper for the roller seat, where the cone of the pivot starts and finishes. Ronda catalogs also don't specify pivot diameters, so i suppose this is where the difference probably is with the two staffs that i have in consideration. Both have the same documented dimensions but most likely have subtle difference and the one big difference of the pivot diameter. Here are the two I'm looking at with the same 5 basic dimensions that are used for listing but 2 different Ronda numbers, and in the Bestfit catalog that doesn't quote a compatability between them.

[JohnR725]

I can't tell from your images is it doesn't say if you had a standard staff versus a staff for a balance shock protection system conceivably could have identical dimensions but shaping differences. In other wars the shock protected ones will have different ends then a standard staff. So while the pivots of the same the shoulder will be different as part of the protection system that's where you might have a difference perhaps

Then there is a way of figuring out balance size pivots if it has a shock jewel system. You would go look up the jewels for the system and will usually tell you the hole size of the jewel.

Then things could be worse you could be trying to do an American pocket watch staff. My personal all-time favorite is Elgin factory number 857. How many 857 staffs do we have exactly? Yes there's different pivots sizes but that's very common on American pocket watches that don't come in more than one pivots size for the most part there are some that only come in one pivots size but there's usually pivots size variations. C a notice that there are actually four separate groups of 857 all the course with different pivots sizes.

This is why have a whole when ever-changing balance staffs always measure the old so hopefully order the right thing. Always measure the new staff to make sure it does agree with the old to avoid those unpleasant surprises.

 

[Neverenoughwatches]

11 minutes ago, JohnR725 said:

can't tell from your images is it doesn't say if you had a standard staff versus a staff for a balance shock

Both staffs are listed as ordinary John

14 minutes ago, JohnR725 said:

I can't tell from your images is it doesn't say if you had a standard staff versus a staff for a balance shock protection system conceivably could have identical dimensions but shaping differences. In other wars the shock protected ones will have different ends then a standard staff. So while the pivots of the same the shoulder will be different as part of the protection system that's where you might have a difference perhaps

Then there is a way of figuring out balance size pivots if it has a shock jewel system. You would go look up the jewels for the system and will usually tell you the hole size of the jewel.

Then things could be worse you could be trying to do an American pocket watch staff. My personal all-time favorite is Elgin factory number 857. How many 857 staffs do we have exactly? Yes there's different pivots sizes but that's very common on American pocket watches that don't come in more than one pivots size for the most part there are some that only come in one pivots size but there's usually pivots size variations. C a notice that there are actually four separate groups of 857 all the course with different pivots sizes.

This is why have a whole when ever-changing balance staffs always measure the old so hopefully order the right thing. Always measure the new staff to make sure it does agree with the old to avoid those unpleasant surprises.

 

Thanks John i will look into the jewel sizes. Thats a perfect reason for me not to entertain American pocket watches John. I appreciate the warning. 

[nickelsilver]

13 hours ago, Neverenoughwatches said:

 Yes i could just try to fit the staff and see what happens which i will probably end up doing, but i just thought it made an interesting question and might apply to making a staff from scratch with a drawing ( do you need more than the 5 sizes ?  and is it a case of improvising as you fit it ?

Check out the AS 1012, made in the bajillions, balancestaffs.com lists 9 different staffs. Even for calibers where there are only 2 or maybe 3 variants, I make the staff if it needs one. You never know if you will get exactly the right one, even from a reliable seller (mixups happen), and you never know if someone in the past mic-macked things to fit a wrong staff (broached out the roller table, or balance hole, or...). The potential time wasted finding the staff, ordering, trying it, figuring out that it's wrong, is just too much. I think the only staff I've ordered in recent memory was for a Valjoux 7733, which they had in stock and was definitely cheaper than my time to make it. And there is exactly one type across that caliber family.

 

When making, I have more than 5 dimensions on my drawing. Diameters: pivot, above hs collet, hs collet, balance seat, hub, roller (2 dimension), and between roller and lower pivot (this and above hs collet are critical for shock settings). Lengths, I measure from the top pivot, to: collet, balance, hub, underside of hub (where roller seats), end of roller, end of staff. A couple more if shock setting. So 14+ dimensions.

[Neverenoughwatches]

32 minutes ago, nickelsilver said:

Check out the AS 1012, made in the bajillions, balancestaffs.com lists 9 different staffs. Even for calibers where there are only 2 or maybe 3 variants, I make the staff if it needs one. You never know if you will get exactly the right one, even from a reliable seller (mixups happen), and you never know if someone in the past mic-macked things to fit a wrong staff (broached out the roller table, or balance hole, or...). The potential time wasted finding the staff, ordering, trying it, figuring out that it's wrong, is just too much. I think the only staff I've ordered in recent memory was for a Valjoux 7733, which they had in stock and was definitely cheaper than my time to make it. And there is exactly one type across that caliber family.

 

When making, I have more than 5 dimensions on my drawing. Diameters: pivot, above hs collet, hs collet, balance seat, hub, roller (2 dimension), and between roller and lower pivot (this and above hs collet are critical for shock settings). Lengths, I measure from the top pivot, to: collet, balance, hub, underside of hub (where roller seats), end of roller, end of staff. A couple more if shock setting. So 14+ dimensions.

I think that answers the question of will 2 staffs with just the 5 basic sizes matching be close enough to be interchangeable lol.  Thanks Nickelsilver my search will continue hopefully it will shorter than learning to make a staff. I could cough up the 30 quid plus delivery from balancestaff.com. and there is a few on ebay that might be ok, it looks like there are only two variations. Shame really, its in a nice big Venus watch from the 50's. 

[LittleWatchShop]

2 hours ago, nickelsilver said:

When making, I have more than 5 dimensions on my drawing.

Yes!

[nickelsilver]

Haha, 14 on the dot!

[nevenbekriev]

I usually make only pocket watch staffs, as I have claimed I do not work on modern watches as this is waste of time and eyes, and I consider as modern all that is younger than 80 years. But I have to make exclusions to this rule for friends…

I don’t use that much sizes, but yes, this 5 sizes in catalogues are not enough. Actually, I will need two more important sizes to make the staff – will name them C and D on the drawing. And, I will not need to know G, J, K and pivot diameters, as I do this sizes in order to fit the parts, that seat there. Further more, there are some rules, that will determine the pivot shape, like that the pivot length should be about 3X pivot diam, so I shape the pivots more like a sculptor than measure and keep exact drawing sizes. And, I usually use the size E for holding the staff in a special collet when I flip it in order to turn the bottom side, so I always do E 1.8mm for pocket staffs and 1.4 for wrist staffs, as this special collets I have have made with this sizes.

Edited November 28, 2023 by nevenbekriev

[JohnR725]

5 hours ago, nickelsilver said:

You never know if you will get exactly the right one

Oh other complications with getting the right staff. I have a theory at least for aftermarket American pocket watch staffs that some of them were deliberately made over size. In other words they expected the watchmaker to reduce them to the proper dimensions to fit. Although one another discussion group somebody suggested that theory was wrong. I based it on one particular balance staff which was a Hamilton 992B staff where there's only one staff it's of friction staff and the aftermarket was physically too large and needed to be reduced just a little bit to fit. So I get suspicious of aftermarket staffs versus original from the company staffs. Which brings up the problem of especially with eBay you have no idea where the staffs came from when they're not in the original package.

5 hours ago, nickelsilver said:

and you never know if someone in the past mic-macked things

Thinking about measurements the book that I got the dimensions from its real purpose is listing of American pocket watch staffs by size. Here's a sample at the very beginning of the book. It doesn't actually say that but my understanding is somebody took a very large assortment of balance staffs and they went through and measured all of them that's were always dimensions came from. But once again there are conflicting theories are thoughts that some of these dimensions are wrong. Or because I can't quite remember the book may be action made up of several people doing measurements and unless they calibrated their micrometers you can always end up with minor little variations because well you just can always have minor little variations.

[RichardHarris123]

3 minutes ago, JohnR725 said:

can always end up with minor little variations because well you just can always have minor little variations.

No such thing as a perfect measurement, only good enough for the task.  Some applications, within 10m would suffice, others 10mm, 10 microns etc. A bit like " no model is correct but some are useful "