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Valjoux 7750 adding the day function - foil required?


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Hi,

I am new to watch repair and have mainly been servicing simple eta movements for my own

I have always wanted a chronograph watch and have found a watch based on a valjoux 7750 with a broken case.

I want to put the movement into a new case but the dial is a day date and the movement is date only.

I have sourced all the parts and have fitted them to the movement to add the day function.

The donor watch didn't use a dial washer / foil, do I need to use one now I have added the day indicator?

If I do need a foil, what size and where from?

 

Thanks very much

 

Stuart

 

 

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IMG_20191027_150808.jpg

IMG_20191029_194719.jpg

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From my experience yes you need it. I have neglected to put it in in the past thinking it was omit-able because it was so thin and flat. Apparently that extra bit of clearance is all that's needed for my day wheel to become dislodged and jam up in short order. I can't find any place where you would get one and the service manual don't even include it. But I guess you can use any generic washer that fits over the hour wheel arbor but not wide enough to peek out the day window and thickness of about a piece of A3 paper.

Edited by CaptCalvin
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I have 3 different tech guides for the 7750 and not 1 has it included. I have added the day function to many 7750s and have never had an issue. The movements with the day function that ive worked on did not have it either.

Sent from my SM-G950U using Tapatalk

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11 hours ago, CaptCalvin said:

From my experience yes you need it. I have neglected to put it in in the past thinking it was omit-able because it was so thin and flat. Apparently that extra bit of clearance is all that's needed for my day wheel to become dislodged and jam up in short order. I can't find any place where you would get one and the service manual don't even include it. But I guess you can use any generic washer that fits over the hour wheel arbor but not wide enough to peek out the day window and thickness of about a piece of A3 paper.

 

9 hours ago, bjd1020 said:

I have 3 different tech guides for the 7750 and not 1 has it included. I have added the day function to many 7750s and have never had an issue. The movements with the day function that ive worked on did not have it either.

Sent from my SM-G950U using Tapatalk
 

 

9 hours ago, thierry said:

Yes, I have been using this great topic below to service a 7750 and there is no washer included either:

 

Thanks very much for the feedback,

So that is two no's and one yes. If it doesn't cause any issues I may add the foil just in case.

Thanks @Lawson for the link to the servicing guide, I look forward to reading it.

 

Stuart

 

 

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12 hours ago, bjd1020 said:

I have 3 different tech guides for the 7750 and not 1 has it included. I have added the day function to many 7750s and have never had an issue. The movements with the day function that ive worked on did not have it either.

Sent from my SM-G950U using Tapatalk
 

That's odd, all the ones with day function I have come across, 3 from Bulova, 2 from Victorinox, and 3 from Mido all have the dial washer.

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13 hours ago, bjd1020 said:

I have 3 different tech guides for the 7750 and not 1 has it included. I have added the day function to many 7750s and have never had an issue. The movements with the day function that ive worked on did not have it either.

Sent from my SM-G950U using Tapatalk
 

   i have a crono that might have the same mvtm.,   without the date wheel.  i'll try to post it.   vin

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18 hours ago, bjd1020 said:

I have 3 different tech guides for the 7750 and not 1 has it included. I have added the day function to many 7750s and have never had an issue. The movements with the day function that ive worked on did not have it either.

Sent from my SM-G950U using Tapatalk
 

There. I knew I've seen it in a tech doc somewhere. It's listed as the "indicator distance piece." It's not in the current version on the ETA website though. 

Screenshot_20191030-133331_Drive.jpg

Screenshot_20191030-133404_Drive.jpg

Edited by CaptCalvin
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Thanks CaptCalvin,

This confirms my thoughts, better to be cautious and use a washer, I can always remove it if the movement / dial combo causes issues.

I have not seen specific washers advertised for the 7750, any recommendations on the size from the documentation, it looks quiet large relative to anything else I have used?

Thanks

 

Stuart

Edited by Swissmade
typo
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Hi,

yes you need it to make it work reliable all the time.

just order  withe Cousins on the UK. The  part number is 2753, is in stock 3 pound a piece.

https://www.cousinsuk.com/category/filter/eta-esa-movement-parts, or ask you watchmaker to order one for you.
 

succes

ronP

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14 hours ago, Ronp said:

Hi,

yes you need it to make it work reliable all the time.

just order  withe Cousins on the UK. The  part number is 2753, is in stock 3 pound a piece.

https://www.cousinsuk.com/category/filter/eta-esa-movement-parts, or ask you watchmaker to order one for you.
 

succes

ronP

Amazing feedback from everyone, thanks I have now ordered the part from cousins. It gets very expensive every time I visit that site.

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I did go back and look and sure enough it is in all 3 of the tech guides I have. However the DIY i also use does not mention it. And now looking at the placement it makes sense why I havent seen it on the ones ive worked on.

Sent from my SM-G950U using Tapatalk

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