Baumgarner BFG 866 - Bringing into beat

[Jon]

Hi,

This is the third instalment on the Baumgartner BFG 866. I wanted to show how to bring the watch into beat

On a previous walk-through of the BFG 866, I have described in detail how to remove the balance and hairspring to be able to oil the cap jewels

 

As you look between the banking pins, the impulse pin is off to the left side slightly, putting the watch out of beat.

The collet is turned in the opposite direction to the direction the impulse pin needs to move. So if in this case the impulse pin needs to move anti-clockwise to get it perfectly between the two banking pins, then the collet needs to be twisted in a clockwise direction

You can attempt to turn the collet whilst fixed to the balance cock, but there is a much greater risk of damaging components, especially the hairspring.

This is the way I teach my students, as it gives them the skills and confidence to remove the hairspring and balance from the balance cock and while removed they can oil the cap jewels as I've shown in this other walk-through on the BFG 866.

I've got two more walk-through's on the BFG 866 that I'll post on the subject of adjusting the friction fitted minute wheel that is on the barrel and removing/re-fitting the centre seconds wheel and oiling the movement...

 

Edited May 8, 2020 by Jon
spelling mistake

[BlueHarp]

Thank you very much, all of you! I think i will practise first on a few other balance wheels, so as not to damage this one.

[rossjackson01]

1 hour ago, BlueHarp said:

Thank you very much, all of you! I think i will practise first on a few other balance wheels, so as not to damage this one.

Vey Wise. I'm in the process of learning manipulation on hairsprings. Applying the same process.

[rehajm]

On 5/8/2020 at 8:47 AM, Jon said:

I've got two more walk-through's on the BFG 866 that I'll post on the subject of adjusting the friction fitted minute wheel that is on the barrel

I need this one- possible to address determining and obtaining the appropriate amount of 'grip' when it could not be previously determined because the wheel was seized from dried lubrication?

[Jon]

3 hours ago, rehajm said:

I need this one- possible to address determining and obtaining the appropriate amount of 'grip' when it could not be previously determined because the wheel was seized from dried lubrication?

I'll post a walkthrough in the next day or two

[Zandr]

Thank you for this, I have a number of 844s in my project queue, and these guides have been very helpful in getting them back into shape. There are a few differences I'm struggling with still, but I'd have been fairly lost in a Roskopf without your posts.

[Nucejoe]

 Nickelsilver Showed this tool, must be nice to have, helps adjusting hairspring to a near zero beat error.   

 

Without the tool , I put the balance less hairapring back on the watch,

      Impulse pin inside the fork horn.

Rotate the balance clockwise while keeping an eye on the fork which moves when impulse pin hits it.

Rotate the balance counter clockwise , the fork move when impulse pin hits the other horn of the fork.

You see an interval within which impulse pin hits either horn, at the midpoint of this interval your balance would be in beat. 

On the rim of the balance wheel ink mark the point thats right in front of the stud holder arm, where the stud is fiited.

Remove the balance and instal hairspring with the stud right on the point you ink marked.  

Your in beat, not sure if the balance complete be in beat as well.  lol

I don't understand why this guy is laughing. . what so funny? 

Rgds

[mikepilk]

Oh for one of those tools.

My procedure is the same as yours @Nucejoe. I have a very little power on the mainspring and make sure one of pallet jewels is centred on a tooth. But even doing this I'm often 1ms out - which doesn't bother me, but will the perfectionists.

This from Fried

  

[Nucejoe]

Hi Mike,

Lets call 1ms error good when done by hand, I am not sure if I can get that accurate even with above shown tool.

I wonder what percentage of the torque/ energy  is  lost  by  1 ms error  , but adds up considerable when multiplied by 24×28800 .

I recently put together a EB1097 out of used parts and  the only fork I had,  pin pallets wouldn't budge without oil, installed a NOS balance complete , not proud of regulation but the result was good beyond expectation, so I gathered accurate beat matters more than I thought.

 Rgds

[mikepilk]

If it doesn't have an adjustable stud holder, then depending on the watch, I consider anything less than about 2ms OK, (and sometimes more). Every tweak risks damaging the hairspring. If it's a valuable watch, or it's impossible to get hairsprings, it's not worth the risk. 

[rehajm]

1 hour ago, mikepilk said:

Oh for one of those tools.

My procedure is the same as yours @Nucejoe. I have a very little power on the mainspring and make sure one of pallet jewels is centred on a tooth. But even doing this I'm often 1ms out - which doesn't bother me, but will the perfectionists.

This from Fried

  

Yes, I’m happy with less than 1ms with this method but 2ms if the balance is quite sensitive. Most of the time a swiss movement gets to less than 1ms in one pass, two at most.

I do think I focus more on what the impulse jewel and location ‘C’ are doing instead of the escape wheel end…

[VWatchie]

Thanks for this excellent tutorial and very fine illustrations @Jon! Really first class! 

On 2/14/2024 at 5:28 PM, Nucejoe said:

 Nickelsilver Showed this tool, must be nice to have, helps adjusting hairspring to a near zero beat error. 

I noticed that your image was a bit too small to read with ease, so here's a larger copy of it.

I summarized @nickelsilver's method for adjusting beat errors to the following, but you can find all the info in the thread I linked to:

“For everyday work, from the smallest ladies’ movements to marine chronometer, I set the balance with the cock on a bench block so the roller table is in a hole, balance on the block. Lift up the cock and move it over- not flipping it, just moving laterally, until I can see the slot in the hairspring collet, get in there and adjust (for tiny watches this is usually with an oiler, larger, a small screwdriver). Go back in the watch and check on the machine. I hold a balance arm of the rim with tweezers while moving the collet.”
 

 

[Neverenoughwatches]

8 hours ago, VWatchie said:

Thanks for this excellent tutorial and very fine illustrations @Jon! Really first class! 

I noticed that your image was a bit too small to read with ease, so here's a larger copy of it.

I summarized @nickelsilver's method for adjusting beat errors to the following, but you can find all the info in the thread I linked to:

“For everyday work, from the smallest ladies’ movements to marine chronometer, I set the balance with the cock on a bench block so the roller table is in a hole, balance on the block. Lift up the cock and move it over- not flipping it, just moving laterally, until I can see the slot in the hairspring collet, get in there and adjust (for tiny watches this is usually with an oiler, larger, a small screwdriver). Go back in the watch and check on the machine. I hold a balance arm of the rim with tweezers while moving the collet.”
 

 

When oozing with confidence, hang the cock from a balance tack, hold the wheel rim with tweezers and feed the tool between the coils to reach the collet slot.