ETA 7001 mainspring problems

[Ishima]

Hi everyone. Since getting back to work i took on a watch for a service with a manual wind eta 7001 and thought it would be smooth sailing. 

 

Unfortunately ive found the mainsprings suplied for this movement via cousins dont even come close to hooking the arbor as the inner loop is too wide, and are much too brittle to adjust (just failed my second attempt)

Does anyone know where/what i can get a mainspring thats sure to work? 

I see gleeve and co sell a mainspring for an eta 7001 but i suspect its not an original but the the same generic, since the price is almost exacly the same.

[rodabod]

Often the hooking radius needs to be altered. Did you do the normal thing and use round-nosed pliers? The ends are annealed, so they should be less likely to snap.

[Ishima]

A colleague advised i tried with two pairs of sturdy, short tweezers, so that is what i did, i spent considerable time on it going little by little, but there appeared to be no point at which the spring would change shape before snapping or splitting, i don't believe the ends on this particular spring are annealed. 

2 springs in the bin and no closer to finishing a nearly due repair, not really willing to give it another go, you know. 

I think if i can't find a more promising mainspring to order I'll just have to have to put it back together and send it through to central workshop and apologise for the delay. 
 

[WatchMaker]

Do you have the original mainspring to measure? The reason I ask is that you've been supplied a 1.00 x .12 x 300 x 9.5 whilst ranfft says you should have a 1.00 x .11 x 260 x 9.0

So is a GR2453 more appropriate than a GR2467 if ranfft is correct?

[MrRoundel]

There's a guy on daBay selling what he says are "Peseux stems for mechanical watches" that includes one for a Peseux 7001, which I believe is the same as the ETA 7001. If they are indeed Peseux branded NOS springs, you should be in luck. Not cheap, but should work if ETA 7001 = Peseux 7001. The seller is in the USA. Good luck.

[MrRoundel]

I meant to say he's selling mainsprings. Doh!

 

[rodabod]

10 hours ago, Ishima said:

A colleague advised i tried with two pairs of sturdy, short tweezers
 

I'm not going to say they are wrong as I've used sturdy tweezers to make light adjustments before. However, it is not ideal, especially when you need to modify the radius significantly. They will potentially cause acute bends which is more liable to cause fracture. I've been there and done that.

It may have been worth trying to anneal the inner coil further on the second spring. But it's easy to say that now with hindsight.

If you are in the UK then I can have a look through my spring selection in case I have one.

[EatPeach]

Hey I hope I can help you. I live in China and there's a considerable amount of spare parts of 7001 taking out from the original movement including the whole barrel assembly and mainspring. Where do you live? I see if the selling can ship to you or not? As for the prize I guess one barrel assembly will be ¥100 that's around $14.

[Ishima]

Thank you all very much for your helpful replies. 

 

On 7/2/2020 at 11:35 PM, WatchMaker said:

Do you have the original mainspring to measure? The reason I ask is that you've been supplied a 1.00 x .12 x 300 x 9.5 whilst ranfft says you should have a 1.00 x .11 x 260 x 9.0

So is a GR2453 more appropriate than a GR2467 if ranfft is correct?

I feel silly for not checking ranfft first, not the first time that website has gotten me out of trouble.
do you believe the inner hook would be on a tighter coil?

I might just try anyway. I'll certainly try and check and compare the dimensions of the original. 

 

Edited July 5, 2020 by Ishima

[Ishima]

Dont mean to keep bumping this thread but i just though id report back and let you know i tried the mainspring suggested by WatchMaker and it worked a treat. It was a near thing, but it hooks without adjustment and now the watch is working well.

 

Thank you a great deal.

[mikepilk]

Apart from Cousins, I often get my mainsprings from here : http://www.obsoletewatchandclockparts.com/770-mainspring.htm