I ceased to post on Omega Forums in the April of the past year because it seemed to me that all discussion were focusing essentially on valuation of watches and, consequently, I felt that I could offer very little contribution to the community, if any. However, last week I received a PM from M'Bob, who kindly asked if all was well with me and, following a brief correspondence, his care has brought me back to the forum. Since. as some of the participants might remember, my primary interest and knowledge is about the technical aspects of Omega watches, I would like to bring the attention of the community to a very important aspect of the role played by Omega/Lemania in the evolution of the modern mechanical timepieces. To cut it short, we all know that, with reference to the figure below, four main types of balance wheels have been employed in the Swiss industry in the golden age of mechanical watchmaking: 1 - Cut Earnshaw steel compensated ring with screws 2 - Cut Guillaume compensated ring 3 - Copper beryllium (Glucydur) wheel with screws 4 - Copper beryllium (Glucydur) wheel without screws This said, given that all of the above balance wheels have been employed by Omega, is someone in possess of a very rare specimen equipped with the second typology?
Yep, here it is.. With a little help of a NATO strap... I must admit it is a bit clumpsy for daily wear
How rare: an observatory timepiece! Have you got a picture of the balance wheel and of the Bulletin de Marche?
Yes, compare the different places where the bimetallic ring is cut. On the Earnshaw bimetallic balance the 2 cuts are very close to the spokes while with the Guillaume balance the cuts are farther off the spokes. The hairspring on my Guillaume balance has 2 end curves (look like Breguet end curves but on both ends of the hairspring). Unfortunately I have not got a photo of it as I did not dare to take the movement apart... some of these competition movements did not even have a regulator - they were adjusted solely by tweeking the hairspring
I find technical discussions interesting. Can someone enlighten on the merits of each type of balance wheels? Also, the shown watch is designed to work in one position (e.g. dial-up)?
A regulator always introduces some sort of perturbation into the isochronism of the oscillating wheel. These particular curves were shaped in order to allow a fine tuning of the isochronism.
A cut Earnshaw steel ring with screws allows a compensation for a finite number of temperatures only (two), a cut Guillaume ring allows a compensation over a range of temperatures. However, the quality of these Guillaume wheels for competition watches was not limited to the temperature adjustment: they also allowed a more precise regulation by means of the particular quality and shape of the poised screws. Of course, the watch was not meant to be assessed in one position only.
In a more gentlemanly era it was attached to a large golden chain and hung around one's neck like Flavor-Flav... No really it just sits in its metal shell, its for testing not for wearing and the fact that a NATO fits it is just a rather hilarious co-incidence.
Very nice! Is that a special cal. 30 with these particular balance and hairspring? The "bulletin de marche" is impressive, in particular the "erreur secondaire", which is very low. We can see here the point of this kind of balance!
I am way out of my league when asking this question but, I have had a number of American pocket watches that the balance looks the same. Am I off base with this comparison?
