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Kif/ shock spring sizing


quantieme

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I have broken the lower shock spring on my eta 7750 balance so I ordered from cousins what I thought was the correct size shock spring for my eta 7750. It was listed in their parts as lower shock spring for eta 7750 part no inca97503, they have turned up but are miles to small their length being about 1.82 mm and my broken one being 2.36mm. I am really desperate could someone please tell me where to get the right size. Thanks 

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If I remember correctly the generic ones on cousins are available in multiple sizes. The movement itself seems to have the standard lyre shaped spring right ? You could try this option...

I wonder if, since the movement has been modified throughout time, the springs exist in various variants...

Edited by Chopin
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According to my "incabloc" catalogue for the Valjoux 7750 the following applies:

Upper spring Ref No. 170.03  = Length 2.31  Width 1.55

Lower spring Ref No. 975.03  = Length 1.83  Width 1.38

 

Cousins supply the lower jewel ref no. INCA 97503

 

Are you sure it is not the upper spring

 

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1 hour ago, clockboy said:

According to my "incabloc" catalogue for the Valjoux 7750 the following applies:

Upper spring Ref No. 170.03  = Length 2.31  Width 1.55

Lower spring Ref No. 975.03  = Length 1.83  Width 1.38

 

Cousins supply the lower jewel ref no. INCA 97503

 

Are you sure it is not the upper spring

 

I think you are right it is the upper spring because I roughly measured it at 2.36 so that more or less ties in with the 2.31.

thankyou for that information, where did you get the sizes from because I couldn’t see any on the cousins listing, it just specified upper or lower.either way I am so grateful because it would have bugged me all night.

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1 hour ago, Chopin said:

If I remember correctly the generic ones on cousins are available in multiple sizes. The movement itself seems to have the standard lyre shaped spring right ? You could try this option...

I wonder if, since the movement has been modified throughout time, the springs exist in various variants...

I think I ordered 5he wrong one, I ordered lower when I should have got upper, thanks for the input though.

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21 minutes ago, quantieme said:

I think I ordered 5he wrong one, I ordered lower when I should have got upper, thanks for the input though.

I have their catalogue. I believe the information is also available in the Cousins "downloads" section.

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1 hour ago, quantieme said:

I think I ordered 5he wrong one, I ordered lower when I should have got upper, thanks for the input though.

Seems that I was wrong which is the upper and which is the lower one when you asked here on the forum a few days ago. My apologies @quantieme . I think the logic is as follows: upper is the side you see when you've just removed the case back and lower is the one "beneath" the incabloc system that you get to see after you take it all apart.

Edited by Chopin
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14 hours ago, Chopin said:

Seems that I was wrong which is the upper and which is the lower one when you asked here on the forum a few days ago. My apologies @quantieme . I think the logic is as follows: upper is the side you see when you've just removed the case back and lower is the one "beneath" the incabloc system that you get to see after you take it all apart.

That’s ok at least I will remember for the next time.

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