Relation between mainspring and balance wheel amplitude

[brunomartins]

Hello!

A well conserved mainspring is essential for a consistent running movement. 
 

Considering a well conserved balance wheel could a low amplitude be resulted of a poor mainspring?

[nickelsilver]

It could be. But in my experience low amplitude is usually due to a number of other issues in the watch, and rarely because of the mainspring.

[mikepilk]

1 hour ago, nickelsilver said:

But in my experience low amplitude is usually due to a number of other issues in the watch, and rarely because of the mainspring.

I think that should be permanently pasted alongside the forum header 

As beginners, I think we all fell in to the trap of thinking poor amplitude is mainly a result of the mainspring. Because we thing we've cleaned everything really well, and the gear train seems OK.

When I started I changed the mainspring every time I serviced a watch. But, on reading advice from @nickelsilver, I changed my view, and now only buy a new spring if the old one is broken, or completely set.  

It's usually dirty/bent pivots/wheels, broken jewels etc. etc. (And often too much play at the top of the barrel arbor, allowing the barrel to rub). 

It's only after years of practice that you learn to spot all the little things that you miss as a beginner. 

 

[Levine98]

1 hour ago, mikepilk said:

And often too much play at the top of the barrel arbor, allowing the barrel to rub). 

After two years of working on mostly 1950s era movements, that has been my experience as well. Nine times out of ten I see the need to use my staking set to close the barrel arbor hole on the plate and see an immediate improvement in amplitude (assuming the other possible causes mentioned above are not present). 

[JohnR725]

1 hour ago, mikepilk said:

completely set.

Even a completely set mainspring wound up tight not super tight but just wound up will still power watch at least for a little while adequately. Or basically I can do a lot of pre-timing with set mainsprings.

Now we do get some or I have amusements with the Swiss watch industry. People who work at a Swatch group service center who have a infinite supply of spare parts will change anything just because they feel like it anything involving timing the escapement they just replace everything. Mainspring barrels they flow like water will change them just because.

But Omega who has working instructions or basically supplemental information is working instruction 67 on how to recycle a mainspring barrel. In other words they explain how to take the mainspring barrel apart check all the components make sure everything looks perfect and seeing as how they even have a working instruction suggests that the majority of time it probably is perfect. Providing the watches get serviced a regular intervals. They go through all the checks put it all back together in a good to go with your used mainspring.

Oh I'm thinking about the life of mainsprings here's something I used for a lecture once look at all the packages with lifetime mainsprings or they will not set or they basically will be perfect forever? Then yes if you look carefully there are the original steel Springs and they don't have any wording is of last forever permanence that sort of thing. But what I find interesting is perhaps in the watch still set but quite a few times I can purchase for American pocket watches original Elgin Hamilton etc. of mainsprings and out of the package there absolutely perfect have nice back curves for better power versus some of the modern white springs that are being made.

[VWatchie]

Fantastic post @mikepilk. So very, very true! 

And I must say, I am (and I believe we all are) extremely grateful for all the advice and knowledge @nickelsilver is sharing! I wouldn't have known half the stuff I now know without his posts and help