Favre Leuba 255 Twin Barrel - Lift Angle ?

[hofnerpres]

Hi all. Managed to find a mint 255 which has avoided the Mumbai Mangler. Runs well after its service but amps are struggling @ 210 deg DU Full Wound. All the usual lists do not specify Lift Angles for these - anybody know ?

Ta

Neil

[watchweasol]

Hi  Suggest you take a look at Ranfft for the 255 and its family models and then check the family with the watchguys lift angles as All the sites I checked out did not have the 255 listed on is own

[nickelsilver]

As I recall this has a 2 arm balance? Should be easy enough to see the amplitude, try a slo mo vid if you can't visualize it.

[hofnerpres]

Yep thanks - good plan. Sadly done that and the Weischi listings etc The movement numbers on the 250 series seem to go 250 to 259 Also 270 to 279 but no Lift Angle info on any that I can see. Probably my stupidity but I have great faith in someone here being less ignorant .....

[hofnerpres]

Thanks Nickelsilver but it's a three arm balance . I really enjoy that old school eyeball method and can get a great result at Plus or Minus 50 degrees !

Edited March 18, 2021 by hofnerpres

[anilv]

https://watchguy.co.uk/cgi-bin/lift_angles

based on the above it states 49 for FL25 (i take it as the 25x family).

Anilv

[JohnR725]

If you want to find out the lift angle the video below shows how. We've discussed it before somewhere on this group. If you really want to see the marking on the balance wheel you made find a highlighting pen with ink that fluoresces. Then use a UV flashlight it really enhances the effect. Otherwise if you use a black.which I originally used it makes it really hard to see what you're doing.

The second llink shows pictures of parts and the various variations for those of us who don't instantly recognize what you have

Then the reason we don't have the lift angle is? I found the parts list for a couple of other versions of your watch and you notice almost specifications but lift angles missing? That's because there were printed at a time where everybody didn't have inexpensive timing machines that can measure amplitude. It's only a relatively modern thing that they print lift angles on tech sheets

 

https://youtu.be/-Xgcck692js

https://www.oldswisswatches.com/watch-parts-branded/favre-leuba-calibre-movement-and-spare-parts/favre-leuba-255/

2717_Favre Leuba 252.pdf 1933_Favre Leuba 253.pdf

[hofnerpres]

Many thanks for the replies - much appreciated. Very interesting point re Lift Angles not appearing on spec sheets - We young pensioners are very spoilt with fancy timing machines and tons of information at our fingertips. I can't find any information on a FL25 listed so it may be referring to the 25x series but that puts me another 10 degrees down. Oh well, I will investigate further and report back. I love the watch.

[hofnerpres]

The slow motion camera trick works a treat. I can report that the answer I get is 53 degrees Plus or minus one  - which should be good enough for a movement amplitude health check. Thanks again all for the advice.