EB 8021 N service

[Khan]

Dear watch enthusiasts 

As a hobbyist, I'd like to ask few questions for EB 8021 N.  

Where do you release the mainspring?

Do I have to remove the barrel Arbor when replacing the mainspring? The Arbor seem to be fixed with the barrel. 

These EB movements are way more trickier compared to any higher quality swiss movements. 

Thanks in advance

Khan

[Airoh108]

That sounds similar to an EB 8810 The arbor forms part of the lid. I had to tighten the mainspring end on the arbor before fitting and wound the spring in by hand to the barrel and lastly rotated the lid the final few turns with the hook tight on the arbor.
Wasn’t easy. Not sure how that mainspring is let down the layout was simple on the Eb 8810 held in place by a clamp.



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[Khan]

That's tough, have tried that in case the mainspring was stuck on the Arbor. The EB 8810 has the click for releasing mainspring on the top. In case of EB 8021 N, it's hidden in lowest part and covered with top plate above barrel. Question is now, how to remove the Arbor and winding disc to securely place the mainspring, please find my images. 

[AdamC]

I serviced one of these about a couple of week ago. I found the ratchet wheel (which is what it is) was friction fitted to the barrel arbor. With some careful encouragement with 120 screwdriver, turning the driver as I rotated the barrel, the wheel popped off. Of course, once off, the arbor was freed from the barrel. Refitting was done using brass tweezers, again rotating while pushing down (not much force required). The servicing went relatively well and the watch is now winds perfectly and is ticking away happily!

Hope that helps?


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[Khan]

Hello Adam

I will give it a try. Thank You very much for advice. And do You have an idea how to release the spring force when fully winded?

Kind regards

 

[AdamC]

Hello Adam
I will give it a try. Thank You very much for advice. And do You have an idea how to release the spring force when fully winded?
Kind regards
 

You would need to remove the calendar mechanism to reveal the click. I’ve added a photo again showing the brass plate removed. You can then release the mainspring tension using the crown as normal.


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[Khan]

Amazing responses! I appreciate your time and effort. I also demounted the Arbor by placing two screwdrivers right below the Arbor on the spring side it popped out. Regarding spring force release, I removed the balance and pallet fork and 'slowly' let the wheels run by controlling with a pegwood (hope it doesn't give wear and tear)..

[AdamC]

Sounds resourceful. I’ve resorted to similar inventive methods in the past. To be honest, it’s probably unlikely the soft pegwood would have caused damage. It will just need a thorough clean.


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[Khan]

Yes, I see. Well, I mean, would the high speed of train wheels due to full wind and free run cause wear and tear in the pivots in such case?

[AdamC]

Possibly. If it unwound uncontrolled then more likely. Inspect the pivots and jewel holes under high magnification to check before reassembly.


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[Khan]

I follow You. Thanks again for sharing your experience. I'm grateful. It may be relevant to other hobbyists as well. 

Kind regards

 

[Khan]

Hello Adam

Would You kindly explain the assembly procedure for the barrel Arbor and the mounting of the barrel disc on the opposite side? After replacing the new mainspring, it seems tough and impossible to push the Arbor in the center..

[luiazazrambo]

Hi there,

any chance someone has a service manual for this movement?

Best regards, 

lui

[luiazazrambo]

Official statement: An EB 8021-68 movement became the victim of my attempt to be a watchmaker. RIP

[AndyHull]

1 hour ago, luiazazrambo said:

Official statement: An EB 8021-68 movement became the victim of my attempt to be a watchmaker. RIP

A quick blast of last post on the bugle, then move on to the next one.

On the plus side, you now have an almost complete set of spares for an EB 8021-68, and you have learned a bit more about the art of watch repair, and who in this game hasn't had to admit defeat from time to time.

[luiazazrambo]

This is a tale of the beginner who went for an adventure:

Found another EB 8021-68 which was very much needed and at the end I managed to put a serviced EB 8021-68 together, now that sounds good, but I feel like the one who won the battle but bleeding from many wounds.

- spent about 3 hours at least with the hairspring twisted and bent by myself as a mistake, followed Marks videos as how to sort it out, at the end it looked like a hairspring again, but only from a distance it was actually a disaster (had to replace)

- broke the second hand, took me a while to realize it though, that little tube came off and stayed on the pivot

- as i re-visited this movement many times and spent so many hours with it a left fingerprints all over it, as not all the time i had finger cots on

- made scratches on the movement and on the dial what I can see even with my eyes

- i did not properly dried one of the train wheel which got rusty a bit and had to clean it up

- lost that little spring which holds the balance jewel in (had to replace)

- and spent about 2-3 hours again trying to put the spring back in place for the quick day change mechanism, went to bed at 1:30 in the morning with a really bad headache  knowing that the spring is somewhere in the room at an unknown location, next day cleaned my desk found the spring spent another hour with it when I realized that there is a window on the cover plate (what I have not tried to put back on earlier) which helps to put the spring back super easy!!!!! cry cry cry cry!!!!!!! awwwwwwwwwwww!!!!!!!!!!

Now it is complete without the second hand and I feel that it is dirty, i would not wear it on my wrist.

I attach a picture with the window marked with red it might save you that headache i had.

 

Edited November 7, 2019 by luiazazrambo

[AndyHull]

That tale sounds strikingly familiar ... I suspect most of us  have done all of those things and many more.

This is all part of the learning process.

If you need a second hand for that thing, you are welcome to come and crawl around the carpet next to my work area, there are at least two of them in there somewhere. I'm sure the carpet sucks them off the bench when I am not looking and eats them. It also owes me at least one incablock spring, and the lower jewel from a Sekonda (and whatever else it ate while I wasn't looking).

You should be able to source a second hand online, look on Ranfft or in the service manual for the size. Cousins et al. have them.

As to the fingerprints, you can probably make those disappear with a cotton bud and some isopropanol or lighter fluid, just don't introduce any cotton fibers in to the works.

Edited November 7, 2019 by AndyHull

[Patrick1]

We had to be in the same battle ... I laugh while reading you, (it's probably nervous) but also because you have humor and we need it, I also started with the 8021n Sicura, everything you've written and more, I've lived it and it's not over ... apart from the nerves, my visa card is crying. Stay strong brothers in arms.
(and thanks google translation, I'm French)

[AndyHull]

Hopefully, I'm going to benefit from the experience gleaned from this thread, as I have an 8021 sitting waiting for my return. 

 

Here's hoping it goes without a hitch.