ETA 7750 disassembled and need advice on mainspring

[noirrac1j]

Hello fellas,

I am at the point of slowly putting this 7750 back together, but want some feed back on the mainspring. I was thinking of just replacing the whole thing. Is it worth it to open the barrel, clean, and re-use the old one, or perhaps just go ahead and buy a whole new barrel complete? I can't seem to figure out how this barrel opens....

JC

[oldhippy]

Doesn't the cap just push off. How old is the watch? What was the reason for striping it down was it just dirt, or dry, if not could it be poor time keeping if so you need to look at the spring. If you open the barrel does the spring look out of shape and poor fitting in the barrel, how are the teeth do they look worn, what about the arbor does that look good. If all look poor then I would replace the whole thing. Seiko used to recommend replace the whole lot if the watch was over 5 years old. 

[noirrac1j]

OldHp,

Thanks for the reply,

I figured out how to open the barrel. It had a "hat box" type cover that I was unfamiliar with. The reason for the overhaul was to complete this new level of watchmaking (for me) and overhaul a chronograph--which after having done alarms, automatics with day/date, jump-hours and hybrid transitorized movements--was the only thing I had not done. The teeth on the barrel look good, the arbor looks excellent, and the mainspring isn't bad at all so I just cleaned the barrel and greased the mainspring with moebius 8300, wiped it with lint free paper, and put it back in. I am not sure how old the watch is, but all functions were working properly. It was running a little fast on the wrist and I confirmed this on a timegrapher. I have it partially put together and running at this point. I could always replace the mainspring now without too much fuss, or let it ride until it goes kaput. I'll figure out what the verdict is when I get more feedback!

J

Edited May 5, 2016 by noirrac1j
typo

[oldhippy]

I think you have answered your own question. Its going fine just needs fine adjustment, so no need to waste money on a spring or complete barrel. 

[vinn3]

congratulations  on finding the opening  procedure for the spring barrel !  vinn

[noirrac1j]

4 hours ago, oldhippy said:

I think you have answered your own question. Its going fine just needs fine adjustment, so no need to waste money on a spring or complete barrel. 

Yes I did....sometimes I just need a little reassurance and a supportive platform to voice my concerns. Thanks Hip!

 

J

[noirrac1j]

2 hours ago, vinn3 said:

congratulations  on finding the opening  procedure for the spring barrel !  vinn

Thanks Vinn,

I don't think I welcomed you to the forum....WELCOME! There's lots of great stuff to learn and fantastic people to share it with, so have some fun and look around.

J

[vinn3]

thanks,  but I was here

[bobm12]

On ‎5‎/‎5‎/‎2016 at 11:23 PM, noirrac1j said:

Is it worth it to open the barrel, clean, and re-use the old one, or perhaps just go ahead and buy a whole new barrel complete?

Sorry Joe, for being late to this post. Congratulations on solving the mainspring problem! Now to answer the question above...my answer would be: why not both? Tinker with the old, to learn; use the new to infuse new life on the movement!

Cheers,

Bob

[noirrac1j]

Bob your suggestions are always in line with my own sensibility. Yes I actually received a new complete barrel/mainspring in time to place it on without having to remove too much stuff. In the course of my slow and supposedly methodical disassembly and reassembly, I managed to lose the chronograph wheel friction (I think it floated away during cleaning even though I used a strainer) and the hour counter lock--which I deliberately placed in an envelope to save, and of course I can't find it! All these delays allowed me to replace the mainspring with a new one. I have most of the works back together but am waiting for that hour counter lock hour.

 

JC

[bobm12]

Ha, that's why I never place stuff in an envelope! I just give the stuff to my kids to play with since I KNOW I will loose the part anyway!

Seriously now, it is a good journey, you'll end up with a top of the line movement, serviced and good all over condition due to the new parts...I say, when things happen there is always a reason! Great job, Joe!

Cheers,

Bob

[noirrac1j]

21 minutes ago, bobm12 said:

Ha, that's why I never place stuff in an envelope! I just give the stuff to my kids to play with since I KNOW I will loose the part anyway!

Seriously now, it is a good journey, you'll end up with a top of the line movement, serviced and good all over condition due to the new parts...I say, when things happen there is always a reason! Great job, Joe!

Cheers,

Bob

Thats funny!

Thanks Bob.

JC