First movement service - some questions

[Bill2024]

Hi All,

I have just "completed" my first service of an old AS 1900/01 movement and I'd appreciate any feedback. I've included images of the before and after timings and brief description of what I did (and did not) do.

I pegged out the jewel holes and pre-cleaned parts with lighter fluid and a small paintbrush then reassembled the train of wheels to see how freely they span - also put in wheels one at a time to see if any issues - all seemed OK to me.

I also looked at the endshake of the wheels and all I can say is that they all had some - honestly not sure if too much/too little etc.

All the parts were cleaned in a manual machine using L&R #111 and three rinses in L&R #3. The balance was cleaned in the machine attached to the plate and then cleaned separately in Essence of Renatta with jewels removed (which were also cleaned in the same solution). Then movement was reassembled and lubricated. There were a couple of things I couldn't do and I'd appreciate any thoughts on how significant these might be; hence some questions:

1) The barrel was not dissembled so the spring is as it was - it did go in the cleaning cycle though. How much of an issue is this?

2) I noticed that, after cleaning,  there is no backlash on the train of wheels when the barrel is given a small wind without the pallet fork in place. The train does stop pretty smoothly though.

3) What is the correct amount of endshake and what might be the symptoms of a movement with too much / too little?

4) When regulating the watch I tried to arrive at an average across all five positions as close to 0 as possible. Is this the correct thing to do? I also had in my mind that is better to regulate slightly fast rather than slightly slow as, intuitively, a watch will slow down between services - is that true?

5) I'd be interested to know if the timing results might be concealing any hidden issues that I'm not aware of - for example the big difference between the dial positions and some of the crown positions.

6) I was unable to remove and lubricate the friction fit pinion on the third wheel. I saw Mark do this on his video but I don't have the necessary tools. Will this just potentially affect the smooth setting of the hands and not the timekeeping of the movement?

Overall I'm pretty happy with it for a first attempt but obviously still a great deal to learn.

Any thoughts much appreciated.

Many thanks, Bill

[mikepilk]

5 hours ago, Bill2024 said:

1) The barrel was not dissembled so the spring is as it was - it did go in the cleaning cycle though. How much of an issue is this?

A big one. It would be like rebuilding a classic car, and hoping it runs well on the old original fuel left in the rusty tank.  Do you have any spring winders? If not, I would still take the spring out to examine and clean. You can hand wind it in, or make a DIY winder using an old washer - people have posted how to do it. 

5 hours ago, Bill2024 said:

2) I noticed that, after cleaning,  there is no backlash on the train of wheels when the barrel is given a small wind without the pallet fork in place. The train does stop pretty smoothly though.

I don't always see what you call backlash either. It depends on the design of the gear train.

5 hours ago, Bill2024 said:

3) What is the correct amount of endshake and what might be the symptoms of a movement with too much / too little?

This is most critical on the balance, but also check each wheel in the gear train. You need some, but not too much. I like to imagine the correct amount as being about the thickness of the pivot. So it decreases in amount as you go through the gear train to the balance.

For regulating, it depends on the type of watch, and who wears it. On a wristwatch I only really care about dial up, crown down and crown left, as these are the positions the watch is mostly in.  You don't need them to be all nealy zero, just cancel out in the most used positions

Your rates are very good, with DU at +4, CD +3 should help to cancel out the CL -7. You will only know when you wear it for a week.

[mbwatch]

5 hours ago, Bill2024 said:

6) I was unable to remove and lubricate the friction fit pinion on the third wheel. I saw Mark do this on his video but I don't have the necessary tools. Will this just potentially affect the smooth setting of the hands and not the timekeeping of the movement?

It won't affect timekeeping. One thing to be aware of though is if there is some dirt trapped in the friction pinion, it will cause extra wear on the parts when setting the hands. That will eventually cause handsetting to become very loose without friction, and then the hands may lose time on the dial even though the movement is running at good rates and amplitudes. A loose/malfunctioning friction pinion was found in every AS 19xx I have opened in the past; it's just a wear-prone part.

You may still be able to get a little bit of oil into it even if you can't disassemble the two parts. Just a very tiny amount of HP1300 poked into whatever seam you can find between the two pieces should be drawn in and held between them.

5 hours ago, Bill2024 said:

for example the big difference between the dial positions and some of the crown positions.

I see no issue here at all, no big differences. Your DU/DD delta is a mere 7s. Totally acceptable for a movement like this. And amplitudes are within 10°.  You should worry if you are seeing >20s between the dial positions, and a big amplitude difference. Those would indicate that you don't have equally clean or equally oiled balance jewels, but your deltas are so small here I doubt that is the case. Regular movement wear on an old watch  that wasn't chronometer grade to begin with would easily account for this small difference.

If you did manage to service the mainspring, I can imagine you might squeeze out another 5-10° amplitude overall. I would be pretty concerned about any moisture or cleaning fluid trapped in the barrel though.

[Knebo]

6 hours ago, Bill2024 said:

The barrel was not dissembled so the spring is as it was - it did go in the cleaning cycle though. How much of an issue is this?

 

1 hour ago, mbwatch said:

I would be pretty concerned about any moisture or cleaning fluid trapped in the barrel though.

1 hour ago, mikepilk said:

big one

Agree with @mikepilk and @mbwatch, this is the biggest issue of what you mention. 

Where are you located? A new mainspring doesn't cost much, e.g. at CousinsUK, if you don't have a mainspring winder. 

 

6 hours ago, Bill2024 said:

5) I'd be interested to know if the timing results might be concealing any hidden issues that I'm not aware of - for example the big difference between the dial positions and some of the crown positions.

The timing results look ok in the table. Amplitude a bit low, but this may very well be caused by the barrel. 

However, we'd be much wiser if we say actual pics of the timegrapher readings. Straight/clean lines? 

 

7 hours ago, Bill2024 said:

6) I was unable to remove and lubricate the friction fit pinion on the third wheel. I saw Mark do this on his video but I don't have the necessary tools. Will this just potentially affect the smooth setting of the hands and not the timekeeping of the movement?

As @mbwatch already wrote. This will eventually become an issue. 

 

 

But overall very good for a first time! You should be happy. 

 

 

[Bill2024]

Thanks everyone for your input.

As @Knebo and @mikepilk have pointed out I should definitely have a go at the mainspring barrel. I don't have mainspring winders but I will have a go a cleaning the barrel and spring and re-installing by hand. I think I'll also try and get a spare mainspring just in case! 

I seem to remember that there is a special oil for mainsprings after cleaning - which I don't have. Could I use 9010 instead?

For the friction fit third wheel pinion, as @mbwatch suggests I'll try and get a little hp1300 in there while it is fitted. I don't want to risk trying to get it off with the wrong tools.

2 hours ago, Knebo said:

However, we'd be much wiser if we say actual pics of the timegrapher readings. Straight/clean lines? 

Lines on the timegrapher are clean and straight in all positions so I hope no issues with anything making contact where it shouldn't. 

2 hours ago, Knebo said:

The timing results look ok in the table. Amplitude a bit low, but this may very well be caused by the barrel.

I was pleased to see a decent increase in amplitude but I don't really know what to expect from a movement of this age. I guess I should definitely see an improvement with either a cleaned or new mainspring.

Edited March 5 by Bill2024
added timegrapher image

[mikepilk]

4 minutes ago, Bill2024 said:

I seem to remember that there is a special oil for mainsprings after cleaning - which I don't have. Could I use 9010 instead?

Not oil but grease. It's usual to apply a thin coat of 8200 to a cleaned mainspring. I put a touch on some watchmakers tissue paper and pull the spring through. When the spring is in the barrel I also add a touch of HP1300 oil on to the coils and base of the barrel. Some do some don't. As two watchmakers about lubrication and you will get three different answers.

[Bill2024]

[mbwatch]

39 minutes ago, Bill2024 said:

I seem to remember that there is a special oil for mainsprings after cleaning - which I don't have. Could I use 9010 instead?

8200 grease for mainsprings but without any of that I would put a little bit of HP1300 on 4 spots around the top of the mainspring after it has been wound in and before closing the lid over. The oil should distribute throughout. But don't use 9010 on the spring. 

Those timegrapher traces are perfect. I would be very happy with that especially if they stay straight over 24 hours.

[Bill2024]

9 minutes ago, mbwatch said:

8200 grease for mainsprings but without any of that I would put a little bit of HP1300 on 4 spots around the top of the mainspring after it has been wound in and before closing the lid over. The oil should distribute throughout. But don't use 9010 on the spring. 

Those timegrapher traces are perfect. I would be very happy with that especially if they stay straight over 24 hours.

Thanks, I think I’ll get some of the 8200 grease.

I’ll also let the movement run and recheck the timegrapher traces tomorrow evening. 

[mbwatch]

33 minutes ago, Bill2024 said:

I’ll also let the movement run and recheck the timegrapher traces tomorrow evening. 

Sometimes it's possible to find a tech sheet where the manufacturer specifies what amplitude and deviations are acceptable at full wind and after 24h. That is more common with modern movements made when timing machines were common, but the cal 1900s might have info out there somewhere.

If not, I'd be looking for straight lines and not more than a 35 or 40 degree amplitude drop over 24 hours. If the crown positions are still over 200° at 24h I'd say that is very good because it will mean the rates stay pretty stable too.

[Knebo]

8 hours ago, Bill2024 said:

Lines on the timegrapher are clean and straight in all positions so I hope no issues with anything making contact where it shouldn't. 

11 hours ago, Knebo said:

The timing results look ok in the table. Amplitude a bit low, but this may very well be caused by the barrel.

I was pleased to see a decent increase in amplitude but I don't really know what to expect from a movement of this age. I guess I should definitely see an improvement with either a cleaned or new mainspring.

That looks fantastic indeed. You should be pleased! Especially compared to the baseline. 

 

8 hours ago, mikepilk said:

and base of the barrel.

Personally, I don't believe in this. I don't think the spring should be touching the lid or base of the barrel, so lubrication there seems unnecessary to me. But let's not have a fight over lubrication 

[mikepilk]

52 minutes ago, Knebo said:

Personally, I don't believe in this. I don't think the spring should be touching the lid or base of the barrel, 

When you insert the spring it is sitting on the base of the barrel. So it must be touching at some points. Whether it needs extra lubrication ?

[JohnR725]

19 hours ago, Bill2024 said:

The barrel was not dissembled so the spring is as it was - it did go in the cleaning cycle though. How much of an issue is this?

If you're not going to clean the mainspring barrel do not run it through the cleaning machine as there's the possibility as others have said of fluid leaking in. Then the problem with not disassembling the barrel is it's hard to lubricate assembled. So for instance the mainspring barrel arbor has to be lubricated. This is where I prefer a grease 9504 or if you're going to go with Swatch group recommendation they prefer HP 1300 on the arbor where it touches the barrel. But they also use epilam to keep that in place which is why prefer a grease unfortunately you cannot grease the arbor Unless it's removed from the barrel.

8 hours ago, mbwatch said:

Sometimes it's possible to find a tech sheet where the manufacturer specifies what amplitude and deviations are acceptable at full wind and after 24h. That is more common with modern movements made when timing machines were common, but the cal 1900s might have info out there somewhere.

Yes the problem of timing specifications before timing machines? Although timing machines for rate have existed for a long time amplitude and beat are relatively modern.

Then PDF documentation? Older stuff was typically scanned by? Don't actually know who scanned the old stuff but they're a typically doing it for parts listings so even though there may have been a complete documentation with many pages on servicing for some watches all we typically will see is a parts list them. So for instance I've attached the parts list for your watch and we get the lift angle.

Occasionally watch companies using a movement might Have specifications. Like for instance the image below basically older watches and noticed there lift angle is missing? So the particular watch company that I swiped this from didn't actually have lift angles for all those watches. But they do give us timing specifications typically only for timing in three positions. Then amplitude at 24 hours. Typically for newer watches it's usually 200° all those below we see it's 190 the lowest I've seen for a really nice grade like a nice Omega might be 160 it can vary by quite a bit but around 200 at 24 hours is a good with the biggest thing of course being keeping time.

 

 

931_AS 1900, 1901.pdf

[Knebo]

1 hour ago, mikepilk said:

When you insert the spring it is sitting on the base of the barrel. So it must be touching at some points. Whether it needs extra lubrication ?

This is an interesting and important question, I think.

Honestly, I don't think the spring (should) touch base and lid. I think the mainspring hovers between base and lid and only touches the arbor and barrel wall. The protruding center rings (see orange arrows in pic below) in base and lid keep that distance, I thought. 

I think the gap is also visible on this picture

[JohnR725]

39 minutes ago, Knebo said:

I don't think the spring (should) touch base and lid.

This is where we run into the interesting problem of distortion of the spring by inserting it into the barrel.  For instance this would be an example of a worst-case example. That's why it's typically frowned upon the hand wine Springs into the barrel as is a concern of distortion like we see below. On the other hand does one set a lecture were somebody claims even using mainspring winders I don't) stated number but even mainspring winders can be hard on mainsprings. Especially if you try to cram it into a barrel too small when your winding it in that leads to all kinds of interesting distortion of the spring.

 

2 hours ago, mikepilk said:

So it must be touching at some points. Whether it needs extra lubrication ?

This brings up the interesting problem of should we be lubricating the mainspring at all? Depending upon whose literature you look at the recommendation is adding lubrication isn't a problem all the way to adding lubrication is a problem. o that means if it is a problem you can't add lubrication anywhere except breaking grease and the arbor as it's going to touch the mainspring and wake in the mainspring.

Like for instance in the Omega document for recycling a mainspring they just wiped the mainspring off inserted in and there's no other grease at all other than HP 1300 on the arbor with of course epilam for practically everywhere to keep it from running away and the breaking grease.

 

[Neverenoughwatches]

12 hours ago, mikepilk said:

Not oil but grease. It's usual to apply a thin coat of 8200 to a cleaned mainspring. I put a touch on some watchmakers tissue paper and pull the spring through. When the spring is in the barrel I also add a touch of HP1300 oil on to the coils and base of the barrel. Some do some don't. As two watchmakers about lubrication and you will get three different answers.

I was thinking about this Mike, I have a feeling I used to do the same , but then wondered why I would use two different types of lubrication on the same thing in the same place. Grease sinks through the coils just as easily.

4 hours ago, Knebo said:

Personally, I don't believe in this. I don't think the spring should be touching the lid or base of the barrel, so lubrication there seems unnecessary to me. But let's not have a fight over lubrication 

What we hope and what actually is might be two different things. Problem is with the barrel is that we don't know exactly what's going on inside it. It's mostly guesswork, gathered from information that the tg tells us, movement performance and put together by our experience. Doesn't hurt to err on the side of caution, a small extra application of lube might help things along and last a little longer as Mike suggests. 

[Kalanag]

If I had a barrel with a mainspring for which I had neither a replacement spring nor a suitable mainspring winder, I would wash and dry the barrel with the mainspring inside but without the cover, and then lubricate it. This is not the best practice, but it seems to be a fairly common one.

[Bill2024]

8 hours ago, Knebo said:

17 hours ago, Bill2024 said:

Lines on the timegrapher are clean and straight in all positions so I hope no issues with anything making contact where it shouldn't. 

20 hours ago, Knebo said:

The timing results look ok in the table. Amplitude a bit low, but this may very well be caused by the barrel.

I was pleased to see a decent increase in amplitude but I don't really know what to expect from a movement of this age. I guess I should definitely see an improvement with either a cleaned or new mainspring.

Expand  

That looks fantastic indeed. You should be pleased! Especially compared to the baseline. 

 

Thank you - itll be interesting to see what playing about with the mainspring does. I've never opened a barrel before or wound in a mainspring so, in case movement performance comes out worse, I have a new spring on order!

[Knebo]

9 minutes ago, Kalanag said:

If I had a barrel with a mainspring for which I had neither a replacement spring nor a suitable mainspring winder, I would wash and dry the barrel with the mainspring inside but without the cover, and then lubricate it. This is not the best practice, but it seems to be a fairly common one.

That makes sense as a last-resort solution 

[Bill2024]

7 hours ago, JohnR725 said:

On 3/5/2025 at 1:38 PM, Bill2024 said:

The barrel was not dissembled so the spring is as it was - it did go in the cleaning cycle though. How much of an issue is this?

If you're not going to clean the mainspring barrel do not run it through the cleaning machine as there's the possibility as others have said of fluid leaking in. Then the problem with not disassembling the barrel is it's hard to lubricate assembled. So for instance the mainspring barrel arbor has to be lubricated. This is where I prefer a grease 9504 or if you're going to go with Swatch group recommendation they prefer HP 1300 on the arbor where it touches the barrel. But they also use epilam to keep that in place which is why prefer a grease unfortunately you cannot grease the arbor Unless it's removed from the barrel.

Thanks. Now I think about it I guess there is no point running the barrel thorough the cleaning cycle while assembled; I won't be doing that again!

I'll take the barrel apart once I've done my 24 hour readings and see how it goes. I don't have epilam so I will use the 9504

22 minutes ago, Kalanag said:

If I had a barrel with a mainspring for which I had neither a replacement spring nor a suitable mainspring winder, I would wash and dry the barrel with the mainspring inside but without the cover, and then lubricate it. This is not the best practice, but it seems to be a fairly common one.

Wish I'd thought of that! I won't aspire to that method but it could make sense sometimes I think, and maybe be less problematic for me at the moment than trying to hand-wind the mainspring back in to the barrel

7 hours ago, JohnR725 said:

So for instance I've attached the parts list for your watch and we get the lift angle.

Thanks but I dont seem to be able to download it - just goes to a blank page. Is there an area of the site with documents that can be searched/downloaded?

[JohnR725]

7 hours ago, Neverenoughwatches said:

Grease sinks through the coils just as easily.

The problem here would be the word grease is a pretty broad term. If we go to the website of the lubrication you'll notice a interesting word which is very important for mainspring lubrication and strangely enough escapement lubrication

Oh and I have a theory? Notice 9415 a synthetic and it is typically referenced in all technical documentation. But 8200 typically isn't reference in any modern documentation? Because in modern documentation we typically don't see the mainspring at all because were supposed to replace the entire mainspring barrel. So I think is the Swiss move on in new directions we don't get a synthetic lubrication for mainsprings because they don't lubricate their mainsprings the way we do including the breaking grease it's why we have things like P125 which is probably synthetic although I have no idea where that actually comes from which I find interesting?

Then there's that word I highlighted thixotropic. As you can see a very interesting lubrication like in the case of 9415 stays in place on the pallet fork jewels until impact and/or sliding becomes extremely slippery. Or 8200 kind of a grease except when things are sliding again than it's basically a oil in a way. Another reason why it make for a very bad breaking grease because once it broke free it's now an extremely slippery oil like substance with zero breaking properties at all. Then what makes 8200 interesting is if you put a blob on top of the mainspring and go away eventually ill be gone because it's absorbed by capillary action into the mainspring so it really does stay in place.

Oh by the way it doesn't entirely stay in place if you put too much mainspring grease in the barrel. Because when it becomes fluid conceivably it will leak out and make a big mess and I'll skip over how I understand that problem. Yes the interesting lessons we learn in life don't put too much of it on the mainspring.

https://en.wikipedia.org/wiki/Thixotropy

3 hours ago, Bill2024 said:

Thanks but I dont seem to be able to download it - just goes to a blank page. Is there an area of the site with documents that can be searched/downloaded?

It's supposed to be a PDF. If you click on it it should open up in whatever he used to look at PDF files. Then the website doesn't have any central location for files as they tend to get scattered all over the message board and they get repeated all over the message board taking up lots of valuable message board space whereas we really should have a library someplace of all these files.

8 hours ago, Neverenoughwatches said:

What we hope and what actually is might be two different things. Problem is with the barrel is that we don't know exactly what's going on inside it. It's mostly guesswork, gathered from information that the tg tells us, movement performance and put together by our experience. Doesn't hurt to err on the side of caution, a small extra application of lube might help things along and last a little longer as Mike suggests. 

I'm not sure that it's entirely guesswork of what's happening in their. Like for instance do we even need a mainspring barrel? Yes we need a mainspring but do we need a mainspring barrel? If you look at some of clocks you'll find that they have no mainspring barrel at all So you can actually can see what happens in between fully wound up tight and fully Let down the mainspring is just kind of floating of their.

Then lubrication err on the side of caution I like that? I'm attaching another PDF and then I'm going to quote something? Then know it really isn't as simple as what I quoted below. We see the name of the mainspring company we find out that there is Teflon on their mainsprings lubricating isn't good for the Teflon. This would explain why Omega recommends just dry wiping the mainsprings if there mainspring indeed has Teflon? Because other problem here is over time various lubricants have been used for the pre-lube mainsprings. Omega at one time had some sort of liquid lubrication and their claim is that yes you can lubricate it doesn't hurt but then in later generations it's dry and don't lubricate it all and definitely don't clean at all. All the way up to the suggestion of the right form of steel itself is lubricating properties and doesn't need any lubrication.

Oh and in some cases I suspect even using 8200 like quoted below sort of were somebody said it doesn't actually help I remember one particular incidents I think it actually made it worse because it was just sticky enough to interfere with the power off the mainspring. But that's only a speculation on one particular watch in one particular time and space.

 

 

2000-08-web-2 mainspring -1.pdf

[Bill2024]

23 hours ago, mbwatch said:

Sometimes it's possible to find a tech sheet where the manufacturer specifies what amplitude and deviations are acceptable at full wind and after 24h. That is more common with modern movements made when timing machines were common, but the cal 1900s might have info out there somewhere.

If not, I'd be looking for straight lines and not more than a 35 or 40 degree amplitude drop over 24 hours. If the crown positions are still over 200° at 24h I'd say that is very good because it will mean the rates stay pretty stable too.

So I just did some more readings after 24 hours and for all 5 positions the average amplitude dropped from 241 to 211 so a drop of 30 degrees. The average rate across all positions fell from 1 s/d to -8 s/d

For the crown positions average amplitude dropped from 233 to 198, a drop of 35. The average rate for the crown positions dropped quite a bit though from -4 s/d to -17s/d

It seems that the amplitude drop is within what is to be expected albeit from a lowish starting point. I'll repeat this with a cleaned mainspring and maybe a new mainspring to get a feel for the difference changes to the spring can make.

[mbwatch]

This is all still very good. Rates tend to spread a lot when amplitude is below 200 but these are still totally respectable numbers for an old watch of average quality.

[Bill2024]

4 hours ago, JohnR725 said:

It's supposed to be a PDF. If you click on it it should open up in whatever he used to look at PDF files. Then the website doesn't have any central location for files as they tend to get scattered all over the message board and they get repeated all over the message board taking up lots of valuable message board space whereas we really should have a library someplace of all these files.

For some reason it wasnt happening when I was using Chrome as my browser - switched back to Firefox and all worked fine. Thanks.

3 minutes ago, mbwatch said:

This is all still very good. Rates tend to spread a lot when amplitude is below 200 but these are still totally respectable numbers for an old watch of average quality.

Thanks - that's good to know. I need to develop a sense of what to expect from different ages and qualities movements.

[JohnR725]

4 hours ago, Bill2024 said:

For some reason it wasnt happening when I was using Chrome as my browser - switched back to Firefox and all worked fine

Strange about the chrome it seems like it should build open a PDF? But I run into similar things as I'm using a browser called SeaMonkey? A lot of the websites I end up at have blank pages they don't recognize it. This means I have to switch to Firefox to look at things quite annoying.

4 hours ago, mbwatch said:

old watch of average quality.

Then it's outstanding that you look at the watch in six positions but for official timekeeping positions typically it's only three. It's easier to have pleasant numbers if you're only pleasing three positions not five or six which typically would be chronometer grade watch. Then the other thing a try with your timing machine is to change the averaging number to something longer than whatever it defaults to. Typically with witschi the recommendation is 20 seconds but the Chinese in the witschi average the numbers slightly differently. But still it might smooth out some of the things a little bit as you're trying to really look for more of an average and not an absolute instantaneous because there can be quite a bit of variations watches do an outstanding job of averaging things over time