Gears, how do watchmakers assess wear & tear?

[Lol-x]

Out of curiosity I would like to know how Rolex or other watchmakers know if the gears in a watch are worn, or beyond service specifications.

The teeth on the gears must wear and I wonder if there is a gauge or measuring device that the watchmaker uses to determine if excessive wear & tear has occurred to the gears.

The sprockets on a bicycle wear out and the wear is clearly visible and the chain slips on the sprockets. However, in a Rolex the gears are so tiny and so I just wonder how a watchmaker determines if the gears just need to be cleaned and re-lubed or whether they need to be replaced

Photo originally from abbyclock.com

[DSJ]

Where's some of our watchmaker friends when you need them!??!

[etp095]

i'm sure a micrometer and a well trained eye help in this matter,just a laymans response.

[RW16610]

Originally Posted by DSJ

Where's some of our watchmaker friends when you need them!??!

Yeah really. Something I would also like more details on.

[MrClean]

with any handheld instrument
there are optical devices, similiar to overhead projectors or projection TVs that you can place the object and a .002" dimension on an object is displayed on the screen as 1/2" so you can visually easily determine deviation or confirm tolerances, but doubt watchmakers use these - they might on the production floor of the manufacturing floor

but suspect the easiest measurement is by clocking the watch or timing it

just a guess, not a watchmaker

[Lol-x]

O.K. but if you timed the watch and found it to be gaining or losing time, how do you know which gear/s are worn and which are not, or whether the gain or loss is due to warn gears and not something else like the balance wheel needing adjustment?

Would the policy be to just replace all the gears, and if so, how many is that??

Damn I wish I knew the answers.

[mickeydainish]

....interesting thread Stevo.... I am keen to find out also... If I could be permitted to hazard a guess... For wear detection on those tiny gears, I would say it is more a visual inspection using magnification. The reason I say this is with such fine teeth and a small contact patch when meshed... evidence of wear and surface metal damage will be clear to a trained eye.... If a part is suspected....then further tests could be carried out??? Just my HO... I await the experts to enlighten us... :-)

[Tools]

Good Question:

Here are the parts that were just replaced in an overhaul of one of mine:

Let's see, I can make out the Stem Tube, Pallet Fork and Jewels, Winding Pinion, Center Wheel, Escape Wheel, Stem Detent and Stem, A bridge...and some other stuff..

None of it looks worn out to me........



This whole mess of stuff doesn't take up much more space than a shirt button..

[dsimon9]

This is a wild guess on my part. But maybe two possibilities.

1. Maybe they check how much slack there is in the movement. I would expect the slack to increase as the parts wear down. If slack is still under specifications, then they assume everything is a-ok? If not then they dig deeper?

2. From tests and/or experience, they know which parts are subjected to the most wear and tear within a given movement. If those parts are within spec, then everything is a-ok?

If they indeed take the movement apart and check the specs in 100% of the parts, then imho they have the patience of a saint.

Maybe it is worth a quick trip to a local, independent Rolex repair shop and asking.

My $0.02 (if that) worth.

Dex

[Vanessa CW21]

You guys are funny....

Okay, this is the deal. We use a very specific tool to inspect the gears, jewels and everything else in the watch! It's called .... a loupe!
Seriously, that's all we need. In extreme doubt I might use a jeweler's microscope, that can magnify up to 50X.
Most of the time the great wheel is worn, as well as the third wheel. In some occasions it's the second wheel or very rarely the escape wheel. Or a combination of any of these. The wear is clearly marked by grooves on the pivots, or a "flat" or "mushroom" shape. The balance staff can show the same grooves, and then it is impossible to regulate the watch within standards. The palletfork will in some cases show wear (=grooves) on the pallet stones, and this means the escape wheel teeth are bad as well. On the reversing wheels (the red ones) the wear is first visible on the back side.
Hope this explains it for you!

[oneillba]

Originally Posted by Vanessa

You guys are funny....

Okay, this is the deal. We use a very specific tool to inspect the gears, jewels and everything else in the watch! It's called .... a loupe!
Seriously, that's all we need. In extreme doubt I might use a jeweler's microscope, that can magnify up to 50X.
Most of the time the great wheel is worn, as well as the third wheel. In some occasions it's the second wheel or very rarely the escape wheel. Or a combination of any of these. The wear is clearly marked by groves on the pivots, or a "flat" or "mushroom" shape. The balance staff can show the same groves, and then it is impossible to regulate the watch within standards. The palletfork will in some cases show wear (=grooves) on the pallet stones, and this means the escape wheel teeth are bad as well. On the reversing wheels (the red ones) the wear is first visible on the back side.
Hope this explains it for you!

Yeah, right... that is what I was about to say...

Thanks, Vanessa!

[topcat30093]

Thank you Vanessa, for the explanation

[Lol-x]

Thanks very much Vanessa

I understand, so it comes down to the trained eye of the watchmaker and his/her skill and experience in judging what parts are worn and what parts should be replaced.

So the loupe is a very important tool, but without it I guess one couldn't really see anything. By far the most value is in the watchmaker's own ability to look at the movement and make a personal assessment of what is worn and what isn't. This can only come from proper training and years of learning and experience.

[East Bay Rider]

I was going to guess they use an optical comparator but Vanessa's explanation is so much better.

[1MAC]

My eyes are starting to cross just thinking about examining the inner workings of these fabulous little machines!

[jac67]

Originally Posted by Vanessa

We use a very specific tool to inspect the gears, jewels and everything else in the watch! It's called .... a loupe!

What is this "loupe" you talk about.




John.

[BiG JeEzY]

Quick question, what is one of the external signs of wear and tear on gears? Will a lower power reserve be a possible sign?

In other words, can you identify if the gears are worn or not without ever having to open up the caseback?

[Vanessa CW21]

Originally Posted by BiG JeEzY

Quick question, what is one of the external signs of wear and tear on gears? Will a lower power reserve be a possible sign?

In other words, can you identify if the gears are worn or not without ever having to open up the caseback?

There isn't always a sign that indicates worn parts...
The Rolex movements are so well made, that even when the watch is running dry and parts are getting damaged, it'll keep running! That's why so many people claim "they haven't serviced their watch in 20 years, and it runs perfect!" Yeah right, untill you look at it with a loupe!
I literally cringe when I hear somebody say something like that to me! I swear... It's like telling a doctor you've been smoking for 20 years and never had a physical, but feel fantastic! Once the x-rays view your lungs, it shows a different picture of your "great health"!

[BiG JeEzY]

Originally Posted by Vanessa

There isn't always a sign that indicates worn parts...
The Rolex movements are so well made, that even when the watch is running dry and parts are getting damaged, it'll keep running! That's why so many people claim "they haven't serviced their watch in 20 years, and it runs perfect!" Yeah right, untill you look at it with a loupe!
I literally cringe when I hear somebody say something like that to me! I swear... It's like telling a doctor you've been smoking for 20 years and never had a physical, but feel fantastic! Once the x-rays view your lungs, it shows a different picture to your "great health"!

Thank you for the reply Vanessa! I will definitely make sure that I strictly follow the guidelines for servicing my watches. I think every 5-7 years is prefect for me.

I even heard of people who would service their watch TOO often on the contrary. They say every 3 years they service them. When I heard that, I thought there was no point. Because I felt, they are having their watch opened up more often then I feel its really necessary.

[Vanessa CW21]

Originally Posted by BiG JeEzY

Thank you for the reply Vanessa! I will definitely make sure that I strictly follow the guidelines for servicing my watches. I think every 5-7 years is prefect for me.

I even heard of people who would service their watch TOO often on the contrary. They say every 3 years they service them. When I heard that, I thought there was no point. Because I felt, they are having their watch opened up more often then I feel its really necessary.

3 years is a little much IMO but it certainly wouldn't harm the inside of the watch. What I would be worried about is the amount of times the watch gets an exterior polish!

[JJ Irani]

Originally Posted by Vanessa

3 years is a little much IMO but it certainly wouldn't harm the inside of the watch. What I would be worried about is the amount of times the watch gets an exterior polish!

Agreed, Vanessa.....just look what happened to my dome!!

[mickeydainish]

Thanx Vanessa..... :-)

[toph]

Originally Posted by jac67

What is this "loupe" you talk about.




John.

something like this, that you hold over your eye and it magnifies the watch or jewellery you are looking at- this one gives 14X the magnification

http://cgi.ebay.co.uk/ws/eBayISAPI.d...2BSI%26otn%3D4

[SPACE-DWELLER]

Originally Posted by Vanessa

(...)Most of the time the great wheel is worn, as well as the third wheel.(...)

Thanks for the info, Vanessa!

Question: If either of the wheels is showing signs of excessive wear, they will be exchanged. But would the exchange of wheels be included in the service charge? Or would it cost extra to have worn out wheels exchanged for fresh ones?

[DSJ]

Vanessa, I was hoping you would weigh in - thanks for all the great information!

[Tools]

Good to see you giving us a bit more on the "inside story" V.

......

[Vanessa CW21]

Originally Posted by SPACE-DWELLER

Thanks for the info, Vanessa!

Question: If either of the wheels is showing signs of excessive wear, they will be exchanged. But would the exchange of wheels be included in the service charge? Or would it cost extra to have worn out wheels exchanged for fresh ones?

Replacing gears is part of the service cost because we usually cannot forsee all worn parts during the making of an estimate for the customer. Now, if I suspect the watch to have excessive wear because of the age, and knowing the history of "never been serviced" the cost will go up. The escapement and automatic wheels are substantially more expensive. Balance staff replacement cost quite a bit as well, and especially if it needs a complete new balance, because of a messed up hairspring...
There are many things we look at when doing the estimate and every watch is different.
On average I would say I replace 2 to 3 worn parts at no extra charge.
Sometimes I end up replacing the balance at no charge, and then I literally loose money on the repair, but it's about doing the right thing for the watch...

[redshirt1957]

Originally Posted by Vanessa

On average I would say I replace 2 to 3 worn parts at no extra charge.
Sometimes I end up replacing the balance at no charge, and then I literally loose money on the repair, but it's about doing the right thing for the watch...

If you will replace JJ's balance I will be more than glad to pick up the cost as a public service to the members. Now, I will not discuss the other 2 or 3 worn parts!

[Vanessa CW21]

Originally Posted by redshirt1957

If you will replace JJ's balance I will be more than glad to pick up the cost as a pubic service to the members. Now, I will not discuss the other 2 or 3 worn parts!

[1MAC]

Wow. Definitely a Freudian slip there Bubba.