Omega 601 sweep second friction spring

[Zedster]

Hi, guys 

I'm currently working on an Omega 601 movement and I need clarification on the position on the sweep second friction spring. I've seen a couple of videos where the spring is located under the seconds pinion. In one video I saw, the guy originally put it on top and it caused the second hand to stutter so he had to correct it.  Now when I dismantled my movement the spring was sitting on top as well, see photo.

Now please correct me if I'm wrong but from all the evidence I've seen so far shouldn't the spring be under the pivot.

I've tried searching for a service manual but to no avail  

 

Also, this is my first higher grade watch I've worked on and its suffering from some moister ingress resulting in the setting lever friction spring and screw (P/N 1132 and 2522 respectively) suffering from rust and can't believe the cost of NOS parts, its crazy! 

[rehajm]

Yes, First the spring. It goes under the seconds pinion. It’s a fiddly one, too - too tight to the pinion can stop the movement and too loose gives you stuttering, but the position of yours looks good. Just pinion on top…

…can you de-rust your screws or too far gone?

Edited August 19, 2024 by rehajm

[AndyGSi]

I think the part no for the screw could be 2624 and these from stemandstaff don't seem that expensive.

https://www.stemandstaff.com/Omega-watch-movement-screws.hD/s405024p/Omega-screw-2624-for-setting-lever-spring-cal-560-561-562-563-565-600-601-602-610-613-750-751-752

https://www.stemandstaff.com/Setting-lever-spring-Omega.fD/s404675p/Omega-pressure-spring-for-setting-lever-470-471-490-491-500-501-502-503-504-505-550-551-552-560-561-562-563-564-565-600-601-610

some of the used listings I've found for the 1132 come with the screw.

https://www.ebay.co.uk/itm/226287262858

Edit

Just realised that the 2624 is for the 1110 and the screw you want is a 2255

 

Edited August 19, 2024 by AndyGSi

[JohnR725]

13 hours ago, Zedster said:

I've tried searching for a service manual but to no avail

The reason you're not going to find a service manual for this watch is it's a basic watch that doesn't require a service manual. Depending upon the watch sometimes if there was something unique there would be a service sheets for that only but not the basic servicing. For instance technical guide for 610 gives you the technical characteristics on the first page second page the parts unique for 610 third page just talks about the balance and on the last page center seconds. As that appears be very similar to yours I will scan that page for you. But as far as servicing information there is none.

Then parts lists the older ones look horrible or in black-and-white and were into parts. Other words 601 unique parts and 600 the base caliber if you're lucky maybe you could find a newer parts list which I did that's attached. Also attached is bonus timing specifications.

Then if you look really carefully your spring is underneath.

 

 

 

 

373_Omega 601 New cousins.pdf

[Zedster]

Thanks, guys

First, I think I made a mistake on the P/N number for the screw, it was getting late when I first wrote my message!

Anyway, I can't even see 2522, my original number, on the parts list so I think my brain was getting confused  

We agree on the friction spring number 1132 

The problem is the screw. 

@AndyGSi Although 2255 is shown in picture form there's no reference to it in the P/N listing unless I should have gone to specsavers  Having said that, I'm sure I saw on eBay a guy selling parts for the 601 and he had the screw listed as 2255. I was going to email the seller for confirmation but haven't yet.

From what I can see from my part list, it says 2642 (not to be confused with 2624) is "Screw for pressure spring for setting lever"

Anyway, I'm going to try and clean the lever and screw up but I need to know if new items are required.

Thanks again, guys!

 

 

[JohnR725]

9 minutes ago, Zedster said:

Anyway, I can't even see 2522, my original number, on the parts list so I think my brain was getting confused  

We agree on the friction spring number 1132 

19 minutes ago, Zedster said:

From what I can see from my part list, it says 2642

The part numbers right description is weird that you can find all watches that have that screw.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=q[[I_H

Then it looks like the screws out of stock which is typical for anything vintage.

http://www.julesborel.com/s.nl/it.A/id.107034/.f

 

[AndyGSi]

Part Number is 2255 and shown in pictures but not in description.

I'd got the 2255 part from here but it's an old link that isn't complete when you click on it.

[Zedster]

Thanks all, I appreciate you taking the time to respond to my inquiry   

[Zedster]

I thought I show a picture of how the spring come out after a bit of scrubbing and a soak in the ultrasonics. The question is do I need to neutralize the remaining scares with something like Evaporust or can I leave alone now? If I have to use Evaporust from what I've seen the whole plate will turn black, please correct me if I'm wrong.

Also, a bit off-topic but no dealt the main reason for the rust in the first place is the crown. I assume this was once a dustproof crown that's seen better days. Although it looks gold I'm assuming again it's because the plating has worn off revealing the base metal as the case is 135.041 stainless. I've searched around and found somebody else looking for the same crown and was given a couple of part numbers, ST42054 which is the modern-day service replacement, and ST42102 which would have been the original from the factory.

I can find these on eBay but again expensive and as I'm not sure of the value of this watch I may end up fitting a generic 

 

[AndyGSi]

Looks like the crown currently fitted isn't the original.

Being a Stainless Case I'd have expected a silver crown 42102ST.

https://gleave.london/crown-steel-omega-st42102/

Spring doesn't look that bad and expect it would clean up nicely.

[Zedster]

Hi, Andy

The end of the crown is silver that's why I mentioned I think the silver on the circumference has been worn away. As for the spring, that is after I cleaned it but I'm not sure whether I need to treat it with something to neutralize the remaining scares 

Thanks for the link, cheapest so far by some margin 

 

Edited August 21, 2024 by Zedster

[AndyGSi]

2 hours ago, Zedster said:

not sure whether I need to treat it with something to neutralize the remaining scares

Still looks solid enough to me so I'd give a quick sand with some fine wet and dry and see what else can be removed before looking at a rust treatment.

Edit

For the difference in size you'd probably get away with one of these crowns.

Edited August 21, 2024 by AndyGSi

[Jon]

On 8/19/2024 at 10:21 PM, Zedster said:

I'm currently working on an Omega 601 movement and I need clarification on the position on the sweep second friction spring.

From your photo of the sweep second pinion spring, it is on the incorrect side. The sweep second pinion turns in an anti-clockwise direction as we are looking at the movement, therefore the spring needs to be on the underside of the pinion at a six O'clock position and not the 12 O'clock position it is in. 

I've attached a photo of a similar movement, a 503, where the brake spring is on the correct side

[Zedster]

3 hours ago, Jon said:

From your photo of the sweep second pinion spring, it is on the incorrect side. The sweep second pinion turns in an anti-clockwise direction as we are looking at the movement, therefore the spring needs to be on the underside of the pinion at a six O'clock position and not the 12 O'clock position it is in. 

I've attached a photo of a similar movement, a 503, where the brake spring is on the correct side

Thanks, Jon

That's a good point  When I come to reassembling the movement I most probably would have just put it back under the pinion without any thought to what side of the pinion it should go. Thanks again!

[CYCLOPS]

I hope you have the bridge....

[Jon]

On 8/21/2024 at 11:55 PM, Zedster said:

That's a good point  When I come to reassembling the movement I most probably would have just put it back under the pinion without any thought to what side of the pinion it should go.

That's where the big leap happens from following photos taken to reassemble a movement, to spotting something out of place, because you know how the movement should work and you are not making assumptions about what you have found when disassembling.

I always tell my students 'Don't assume what you find is how it is meant to be.' Like the brake spring. You'll be surprised what you find when you look at a movement with scepticism.

[rehajm]

33 minutes ago, Jon said:

That's where the big leap happens from following photos taken to reassemble a movement, to spotting something out of place, because you know how the movement should work and you are not making assumptions about what you have found when disassembling.

I always tell my students 'Don't assume what you find is how it is meant to be.' Like the brake spring. You'll be surprised what you find when you look at a movement with scepticism.

A valuable lesson as usual, Jon but could you elaborate for me, the accountant the mechanics involved that would lead to this conclusion? Specifically if tension on the 12 o'clock position poses a problem why do the yoke style springs prevail?

...Getting these springs correct is so critical to amplitude and seconds hand function any more insight is appreciated...

Edited August 26, 2024 by rehajm

[SwissSeiko]

1 hour ago, Jon said:

That's where the big leap happens from following photos taken to reassemble a movement, to spotting something out of place, because you know how the movement should work and you are not making assumptions about what you have found when disassembling.

I always tell my students 'Don't assume what you find is how it is meant to be.' Like the brake spring. You'll be surprised what you find when you look at a movement with scepticism.

I see mostly vintage watches in my shop, and the first thing I do is make a note if there are any makers marks on the case back. Lots of shotty previous services going on out there, and fixing their mistakes may not always be 100% functionally necessary, but I have to do it for my own sake. So many missing screws!

[Zedster]

On 8/26/2024 at 2:14 PM, Jon said:

That's where the big leap happens from following photos taken to reassemble a movement, to spotting something out of place, because you know how the movement should work and you are not making assumptions about what you have found when disassembling.

I always tell my students 'Don't assume what you find is how it is meant to be.' Like the brake spring. You'll be surprised what you find when you look at a movement with scepticism.

As a learner before attempting to disassemble any movement I look to see if any videos are on YouTube and that is where I saw a guy re-assemble the 601 and he made the mistake of putting the spring on the top which resulted in the stuttering seconds hand, he went back and corrected it. Obviously, when I took mine apart I noticed the spring was on top, hence my concern.  

[Jon]

On 8/26/2024 at 2:47 PM, rehajm said:

Jon but could you elaborate for me, the accountant the mechanics involved that would lead to this conclusion? Specifically if tension on the 12 o'clock position poses a problem why do the yoke style springs prevail?

The reason the brake spring should be in the 6 O'clock position is because when the pinion turns in an anti-clockwise direction the pinion leaves should be dragging away from the end of the spring. In this orientation there is no chance the spring will catch on the pinion leaves as they turn, especially if the end of the spring is damaged in any way. If the spring was in a 12 O'clock position, which is incorrect, as the pinion leaves turn they are turning into the spring and as I've said if the end of the brake spring is damaged it may catch the pinion leaves and bring the watch to a stop as the spring lodges itself into a pinion leaf. In the 6 O'clock position this could not happen.

This type of centre seconds hand, which is known as an 'indirectly driven' sweep second movement, as opposed to a directly driven sweep seconds movement, which has a fourth wheel passing through a hollow centre wheel or like ETA do it, the fourth wheel (which they call the 'seconds wheel'- not confusing at all!... lol) passing through a fixed centre pipe and cannon pinion and driving wheel which is synonymous with ETA design.

Anyway, I got away from the point I was trying to make, that most modern watch designs don't tend to use a brake springs, sweep second pinions, or an 'indirect drive' sweep second design. These are old types of movement layouts. The spring that goes underneath the sweep second pinion obviously has a cock that goes over it, as the spring pushes the pinion upwards towards the jewel. The other sort is what you would find on vintage Rolex's and the like, with a brake spring on top of the sweep second pinion, as in the photo of this Rolex 1570

The problem is that because many fettlers have been at these types of watch movements and have fitted the second hand without properly supporting the pinion and brake spring by putting a small slither of mainspring between the the top of the pinion and the underside of the brake spring and then support the lot on a block as you fit the second hand, otherwise the spring will get a nice dent in it where it makes contact with the pinion and that will drastically decrease the amplitude. I would say about half of all brake springs of this type are dented. Always best to try and flatten it back out. The good thing about brake springs are if the amplitude is too high and causing knocking, you can increase the tension of the spring against the pinion to reduce it.

In the ideal world, there should be just enough tension to stop 'flutter' or what is known as 'backlash' where the second hand stutters instead of sweeps. There should be no more than about a 10 to 20 degree drop in amplitude when the spring is fitted; the less the better without creating flutter

[rehajm]

Amazing as usual Jon- thank you for the expanded explanation! I see so many indirectly driven seconds movements and thus this type of spring, though they are usually of the yoke style, like Longines 10L. Most of the springs are bent a bit as you describe-  what a great suggestion to avoid it….ty again…