Jump to content
  • 0

Difficulty identifying balance staff sizing - AS1287


Question

He'll everyone. I have had an AS1287 inside a 50s-60s Iram military style watch for too long, and have had continued issues with it relating to the balance staff. 

 

There appears to be two versions, an earlier non shock balance and a later Inca setup. No matter what I try I always seem to end up with the shorter Inca staffs or balance complete. I've tried four so far and I am getting frustrated. 

Does anyone know of any documentation that would show me the correct staff measurements for a non shock AS1287?

I have found what I think is the right staff (pictured) and have included the ones I currently have (the packet on the watchmakers mat), however I don't understand the measurement method on the packets. Can someone please confirm which of the two is the longer (higher)?

 

Any help much appreciated, especially relating to the measurement standard. thankyou.

20210622_145744.jpg

Screenshot_20210622-145721_eBay.jpg

Link to post
Share on other sites

5 answers to this question

Recommended Posts

  • 0

If you want some measurements on a non inca there is the one which says sold out BS5484, which is slightly longer than the inca version, guess the BS0414 might be some equivalent but not sure since the rest of the measurements are missing from the BS5484.
Notice there also exists atleast a third version for the supershock. ( And probably some more). So, measure your balance carefully.

https://www.balancestaffs.com/a-schild.php?caliber=1287

Link to post
Share on other sites
  • 0
Posted (edited)
1 hour ago, HSL said:

If you want some measurements on a non inca there is the one which says sold out BS5484, which is slightly longer than the inca version, guess the BS0414 might be some equivalent but not sure since the rest of the measurements are missing from the BS5484.
Notice there also exists atleast a third version for the supershock. ( And probably some more). So, measure your balance carefully.

https://www.balancestaffs.com/a-schild.php?caliber=1287

Thanks for your reply. I unfortunately don't have an original staff to measure, as I bought the movement without a balance. Therein lies my frustration. The site you linked to is very helpful though, hopefully I can measure my existing (recently bought) staffs and take it from there.

Edited by Pauldoubleyou
Link to post
Share on other sites
  • 0
2 hours ago, Pauldoubleyou said:

There appears to be two versions, an earlier non shock balance and a later Inca setup. No matter what I try I always seem to end up with the shorter Inca staffs or balance complete. I've tried four so far and I am getting frustrated. 

Does anyone know of any documentation that would show me the correct staff measurements for a non shock AS1287?

I think what the problem here is you're asking the wrong question. The question is what part number do I need so that I can end up with the correct balance? Or the correct balance staff for that matter? If you look at the second link it lists the parts for your watch. This is always where things get interesting? you'll notice for balance staff they list seven different ones. For balance complete they do show three but if you look at the part numbers there's only two.

then I attached some images from bestfit online and of course additional problems perhaps. Notice you have lots of choices and probably only one that's right.

then the physical bestfit book becomes interesting because is an indication that there are variations which is of course why there so many listed in the images. but fortunately it looks like you want the basic simple one which should be 100/66.  unfortunately for the third link it's out of stock. then providing this is the right staff number I snipped out a couple of more images of the bestfit book which is what the dimensions mean and the dimensions. One of the irritating things of the physical book is on the dimension chart if you're trying to find a particular staff you just have to be lucky to go through the list and find it it be really nice if they list of the sizes by the numeric staff also.

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&AS_1287

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=AS_1287

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=U\ZD]J

http://www.julesborel.com/s.nl/it.A/id.151223/.f

 

as 1287 1.JPG

as 1287 2.JPG

100 66 staff size.JPG

staff dimension best fit 100 parts.JPG

Link to post
Share on other sites
  • 0

I have found using as much data from the old balance is most useful. Even when purchasing the correct balance some tweaking is often required 

Link to post
Share on other sites
  • 0

Hi,

16 hours ago, Pauldoubleyou said:

Does anyone know of any documentation that would show me the correct staff measurements for a non shock AS1287?

Any staff manufacturer's catalog (Ronda, DCN) shows the sizes. You already got them above (L=290).
Ronda's is available as pdf on the Cousins website.

16 hours ago, Pauldoubleyou said:

I have found what I think is the right staff (pictured) and have included the ones I currently have (the packet on the watchmakers mat), however I don't understand the measurement method on the packets. Can someone please confirm which of the two is the longer (higher)?

The staffs in your 1st picture are totally wrong. "1287" is Ronda's staff number - not the calibre, which you find below: "IMER 485". Its length is 308.

There are no staff sizes on the packages.

BTW. the length difference of AS1287 staffs is minimal: ordinary 290, Incabloc 287 (all are 1/100 mm).

Frank

Edited by praezis
Link to post
Share on other sites


  • Recently Browsing

    No registered users viewing this page.

  • Topics

  • Posts

    • I bought this for my new watch bench. It is nice but because of the way you work on a watch bench, the lamp is mounted on the same plane as your work space (this is higher than if it were a typical work bench).  As a result, the lamp cannot pivot upward enough to get optimal positions. So, what I had to do was design and print an short extender that pushes the fulcrum of the lamp away from the manufactured pivot point.  This allows me more range of motion. I am pretty happy with how it turned out.
    • This purchase must qualify:
    • Please keep us posted though. It's a beautiful clock and well worth a bit of time and effort to get it back to it's original glory. Good luck!
    • Did a bit more today on my Hettich. I also mucked around with practising on the top plate from the second Hettich that I bought. The calico wheel can leave marks and I am being gentle. I am certainly not pushing the plate into the wheel. I could easily stall the bench grinder that I am polishing on. I am wondering if Hettich started to use a lower grade of brass? I still cannot polish the brass to a mirror finish. On my Hettich (older) I have had to emery one of the posts that supports the movement and after 600 grit then 1500 grit, straight to Tripoli on my stitched wheel, then green on the calico wheel and the post is spotless. Absolutely gleams. post has a steel nut on the top of it that was rusty and affected by the battery acid. It is now polished as best as can be done and then I mucked around with a bit of heat and have changed the colour of the nut which looks quite good now. It was black originally. I have done several jobs now by hand where a having a lathe would have been so much quicker. Have to get rid of the Esprit first. Then I might have a chance.
×
×
  • Create New...