Baumgartner BFG 866

[watchweasol]

Hi Jon   nice work we be welcome by many Iam sure. A very good reference document.

[VWatchie]

Thanks! Excellent write-up! Bravo! 

[TimpanogosSlim]

Hey, thanks for this. I've read through it twice now, because part of my interest is in jump hour watches. I only have one BFG 866 jump hour, but i have two BFG 582 jump hour, and two UMF 24-34 which as you know is a similar design. 

I have a question about lubrication. 

Ironically, my BFG 866 jump hour is the 21J variation. But most of these are 1 or 0 jewel movements. I have maybe half a dozen 866 3-hand movements. 

It seems like the pivot-to-bearing area is larger in these than in jeweled movements, because the bearing is thicker, so perhaps slightly more oil is called for? 

And i have to wonder if the same viscosity is warranted as with jeweled pivot movements in the same size. Specifically i wonder if something heavier than 9010 might be better? 

My BFG 582 movements seemed to have been liberally lubricated with a mixture of 3-in-1 and Mel-Fry which had polymerized into a stiff goop which appears to have been why they stopped working. The bearings don't look ovaled-out like the ones on my UMF 24 movements. Short-lived lubricants for the win? 

Edited January 4, 2022 by TimpanogosSlim

[SAK335]

On 10/23/2020 at 2:21 PM, Jon said:

I've just posted a PowerPoint presentation of removing and re-fitting the friction fitted minute wheel.

Hope it helps. Any questions, don't hesitate to ask, as I expand on the lesson in the class room, so end up explaining more than is in the pictures and captions

Hi can you explain what a "tight fit" on the collet means?  Does it mean that the minute wheel can turn on the collet, or does it need to remain stationary and only turn with the barrel?  

[Jon]

On 2/4/2022 at 12:56 PM, SAK335 said:

Hi can you explain what a "tight fit" on the collet means?  Does it mean that the minute wheel can turn on the collet, or does it need to remain stationary and only turn with the barrel?  

With the 'tight fit' you should be able to turn the minute wheel on the barrel with your finger and thumb. The tighter it is, the tighter it feels when you 'hand set' the hands and looser that friction is, will feel sloppy and loose when setting the hands. It takes a bit of practice to find that 'Goldilocks' spot of how much friction to create with the staking tool.

[SAK335]

4 hours ago, Jon said:

With the 'tight fit' you should be able to turn the minute wheel on the barrel with your finger and thumb. The tighter it is, the tighter it feels when you 'hand set' the hands and looser that friction is, will feel sloppy and loose when setting the hands. It takes a bit of practice to find that 'Goldilocks' spot of how much friction to create with the staking tool.

Thanks, that's very helpful.  I am refurbishing my second one of these now.  On the first one, I didn't mess with this part because I didn't know that the wheel could be removed.  That watch is running nicely.  The current one went together much easier (owing to my being more familiar with the movement) but the hour and minute hands wouldn't turn.  I had originally put the minute on so that it turned freely with almost no resistance after seeing that the wheel could be removed.  I'm not sure if installing it so loose would cause this problem.  I've disassembled it again and armed with this information, we'll see if it makes a difference after an adjustment.

The finished first watch is below.  The second has a nice case but the dial has been relumed and isn't quite as nice as this one.

[Burruz]

On 3/17/2020 at 10:51 AM, Jon said:

Hi,

I teach watchmaking to complete beginners at Epping Forest Horology Centre, close to Epping and this is one of the lessons on the BFG 866.

I wanted to show my class a classic pin pallet (Roskopf) movement and how to service it, as many watchmakers won't touch these watches as they hold no monetary value. 

 

Turn the setting lever screw 1 to 1 and a half turns to release the winding stem

A piece of watch paper or small plastic jiffy bag to protect the dial, whilst removing the hands

The driving pinion is part of the friction fitted minute wheel on top of the barrel. This work in a similar way to a friction fitted canon pinion to set the watch hands

 

Remove the keyless work: setting lever, held in place by the setting lever screw, screwed from the other side of the mainplate, then the yoke, which sits on top of the clutch (castle) and also the winding pinion.

I have three other lessons on this movement that cover bringing the watch 'into beat' as well as taking apart the friction fitted minute wheel from the barrel, lubricating and staking back on to achieve the correct friction setting and finally how to remove the centre seconds wheel safely and refit using a staking set. Many people leave the friction fitted minute wheel on top of the barrel, not realising the amount of old grease that can't be cleaned out from it, as well as not removing the wheel of the centre seconds arbor and again not cleaning out the pipe which has old grease inside.

Hope you enjoyed the tutorial? More to come....

 

Hi Jon

This is great! A watch with this movement has just arrived so this is very handy. The stem is floating in and out so I suspect a setting lever spring issue as you described. Thanks again.