Can anyone tell me the range of amplitudes that would be approprite for a vintage 861 movement? If I set my timegrapher for a lift angle of 40 degrees, I'm seeing a range of 220 to 250 degrees depending on orientation. Rate measurements look good and steady ranging from 2 to 6 sec/day, and beat error is very low. Seems pretty good to me, but looking for a more informed opinion.

Thanks! --- and of course a photo:

 

Try this.

http://hiro.alliancehorlogere.com/en/Under_the_Loupe/Calibres_with_a_50_Degree_Lift_Angle.html

 

Now I’m really confused — this lists the 861 lift angle at 50 degrees. Everything I’ve seen previously said 40. Can’t open the referenced spreadsheet on my phone - I’ll try later. Does it specify amplitudes?

Thanks!

 

Everything I have seen for 861s and 1861s indicates 50 degrees (mind you, this is just from searching; I am only a keyboard watchmaker )

Here is a reference from Chronomaddox:

http://chronomaddox.com/omega/manuals/service/861/861_service_manual.html

 

40 degrees does sound low for a modern movement. Maybe Al @Archer can chime in...

 

Here's something fairly comprehensive from WUS.

 

LA of 50 deg. Sounds right. Once you change your Timegrapher to the 50 LA setting, you’ll get much better numbers, prob ~+70 deg., which would be c/w a healthy 861 !

 

It is 50 degrees for these.

Regards, Chris

 

Thanks all for the correction! I’ll use 50 degrees

 

40 Degrees is correct for the 321 Omega movement, so I guess that's where you got that number?

 

Exactly — I mistakenly assumed the 861, as a derivative of the 321, would have the same lift angle. Glad to be corrected - my timegrapher readings will now look a lot better!

 

The thread on WUS is very useful — thanks for that. Great writeup by Archer in it. I’ll need to bookmark that one.