Sometimes, it’s hard to understand what engineers were thinking when looking at some watch movement features. One of the worst offenders I can think of is the otherwise excellent Valjoux 7750 chronograph movement.
Try to change the date with the quick-set function too close to midnight, and you are in for a surprise – a sizeable repair invoice from your watchmaker!
Have a look at this Valjoux 7750. Next to the “14” on the date disc, you can see the brass coloured date change wheel, and the little triangular bit that should advance the date has broken off. You can see the same wheel as the day change wheel on the left and above, with the triangular tip intact.
Firstly, I can’t understand making a movement with such a “feature”. Yes, the manual for the watch will tell you not to quick-set the date close to midnight, but who reads manuals, and who remembers? Secondly, after lots of your customers have broken their date change wheels, and after a fair amount of decades, you might want to improve the construction to prevent this from happening?
Nope, no chance. ETA now makes these movements, they have been around for decades, and they still haven’t fixed the problem.
Yes, it’s that simple. The post on the wheel transports the date change tip, and if the quick-set is operated, the tip can just turn away clockwise. A Chinese engineer had to come up with this. And well done to him or her!
I have a few of these in stock, and use them when I get a 7750 with a broken date change wheel.
So, dear ETA boys and girls, how about copying this excellent little construction from the Chinese, and make your customers a bit happier than they are now? And, whilst you are at it, how about supplying us independent watchmakers with parts? 😉