balance pivot shock spring on my st3620 different to the eta 6497

[Bill2024]

Hi All,

I'm going through level two of the course and I noticed that the movement Mark uses (the eta 6497) seems to have a different type of shock spring than the one on the Chinese clone that I have for the course (image attached). Although I have not been brave enough to attack it with the screwdrivers yet I'm not really sure how this spring would come off.

From what I understand the movement I have is a clone of the one Mark uses with the exception of the small seconds hand being at the 6 o'clock position.

Any advice on how to approach this would be appreciated.

Best,

Bill

[RichardHarris123]

It needs rotating until the narrowest arm comes out of here  

[Bill2024]

1 hour ago, RichardHarris123 said:

 

It needs rotating until the narrowest arm comes out of here  

 

Ah I see - thanks very much. I hadn’t noticed the indentation in the surround of the spring. 
Is this best attempted with tweezers or a small screwdriver?

[RichardHarris123]

As usual there are tools for this but members have made their own from peg wood. They just cut three prongs. 

[Bill2024]

39 minutes ago, RichardHarris123 said:

As usual there are tools for this but members have made their own from peg wood. They just cut three prongs. 

Thats a great idea - gonna take some practice I reckon! Thanks very much. 

[LittleWatchShop]

26 minutes ago, Bill2024 said:

Thats a great idea - gonna take some practice I reckon! Thanks very much. 

Actually quite easy.  I posted about the pegwood tool I made.  I will try to find it.

 

Here

Edited December 4, 2024 by LittleWatchShop

[Bill2024]

1 hour ago, LittleWatchShop said:

Actually quite easy.  I posted about the pegwood tool I made.  I will try to find it.

 

Here

Very interesting, thank you. 

[GPrideaux]

In my (limited) experience, it usually comes off easily with a pair of tweezers in each hand. After losing one of these early in my journey as a hobbyist, I now work through clear plastic when removing these (or anything else with 'spring' in its name). I can sometimes reinstall them with just two pairs of tweezers (and the clear plastic) but the pegwood turner can be helpful if it's obstinate once the first two arms are in place.

[Neverenoughwatches]

8 hours ago, Bill2024 said:

Thats a great idea - gonna take some practice I reckon! Thanks very much. 

This one isn't so bad, as you only have to deal with two of the prongs and only one at a time then lift out. There's a shock spring that has 3 notches, and all three prongs have to locate into them at once and then turn to lock the spring in, quite tricky and that one does require a Kif Trior spring tool or a homemade wooden one. But this one just needs a probe to turn it and another placed at it's center to keep it from jumping away. You can use a clear cover over the top if you wish, but I dont think its necessary if you use a center probe. I'll dig one out if you need a demonstration,  but i think you'll manage just fine.

Edited December 5, 2024 by Neverenoughwatches

[Bill2024]

 

On 12/5/2024 at 6:32 AM, Neverenoughwatches said:

You can use a clear cover over the top if you wish, but I dont think its necessary if you use a center probe. I'll dig one out if you need a demonstration,  but i think you'll manage just fine.

@Neverenoughwatches If you do have, or know of, any examples of this type of spring being removed that would be much appreciated. And can you tell me the name of this type of shock setting please? The only ones I seem to find videos of are the incabloc ones. Thanks. Bill

[Neverenoughwatches]

58 minutes ago, Bill2024 said:

 

@Neverenoughwatches If you do have, or know of, any examples of this type of spring being removed that would be much appreciated. And can you tell me the name of this type of shock setting please? The only ones I seem to find videos of are the incabloc ones. Thanks. Bill

Last xmas shopping today, but when i get home I will have a look. I am sure that I will have something similar. 

[Bill2024]

5 minutes ago, Neverenoughwatches said:

Last xmas shopping today, but when i get home I will have a look. I am sure that I will have something similar. 

Much appreciated. Hope the Xmas crowds are not too overpowering!

[mbwatch]

12 minutes ago, Neverenoughwatches said:

And can you tell me the name of this type of shock setting please?

That looks to be a Seiko Diashock spring (the 3 arm type, rather than the 2 arm found in the NH3x movements). This is a great reference post naming the different shock springs you will encounter.

They are without a doubt easier than other types of 3 arm springs because you only have one slot to align and they are robust & hard to break. But they are harder than Incabloc because they are not hinged and can fly away & must be placed back when reassembling. 

And here is Mike Bolton on MRW demonstrating how he deals with them.

 

[Bill2024]

2 hours ago, mbwatch said:

That looks to be a Seiko Diashock spring (the 3 arm type, rather than the 2 arm found in the NH3x movements). This is a great reference post naming the different shock springs you will encounter

Thanks very much. Given that it’s a Chinese clone movement I’m working on, do you think it’s likely that they have just copied this shock spring from Seiko. 

without wanting to jinx it, do you think a seiko spring would fit into the ST3620 if I were to loose one?

3 hours ago, mbwatch said:

And here is Mike Bolton on MRW demonstrating how he deals with them.

 

That’s great thanks. 

[mbwatch]

7 hours ago, Bill2024 said:

without wanting to jinx it, do you think a seiko spring would fit into the ST3620 if I were to loose one?

It probably is a Seiko made spring rather than a Chinese copy. But Seiko does make different sizes so you would need to get the right one if you needed a replacement.