# Bird's Nest Movement



## Silver Hawk (Dec 2, 2003)

The Olympic stadium was aptly named...and I now propose we call the Longines Cal 6512, the "Bird's Nest Movement". 

I've always been fascinated by the appearance of this movement --- it's the one on the back cover of Doensen's "History of the Modern Watch" book. I don't own one, I'd like to ... but they seem very rare. They're found in the Longines Ultra-Quartz range.

A colleague is sending me one to fix...I've already warned him "No chance!" ...unless its a straight forward mechanical issue; it is currently in Switzerland but Longines have said they wont touch it.

Before I forget, the owner is contemplating replacing this Bird's Nest Movement with a modern quartz replacement if it cannot be made to work...but the Ultra-Quartz watches are all back set. Anyone know if there is quartz movement that is back set?

A few pictures (taken from the 'net without permission). I'll post a few of my own when this other example turns up.


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## KEITHT (Dec 2, 2007)

Wow , now that is one rare peice....the worlds first Cybernetic movement ( apperantly ).

I agree Paul, The birds nest...and very apt name...

Missed out on one of these last year....was trying to buy a CEH ' Beta 21 prototype ' at the same time and missed both...doh!


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## seiko6139 (Aug 25, 2003)

I've never seen one of these Paul.

I see that it's made up of discrete transistors rather than an IC.

Thanks for sharing!


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## jasonm (Nov 22, 2003)

Bloody hell!

Good luck :huh:


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## Silver Hawk (Dec 2, 2003)

KEITHT said:


> Missed out on one of these last year....was trying to buy a CEH ' Beta 21 prototype ' at the same time and missed both...doh!


Thanks Keith. If you see or hear of one, and you don't want it (fat chance of that :lol: ), please let me know.

The dial, case and hands on the one above look so ordinary to me...under normal circumstances, I wouldn't have given this watch a second look.

Here is a quick photo of the one that is bust and heading my way....looks a lot more interesting to me:


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## PhilM (Nov 5, 2004)

Good luck with that one Paul, it looks like they put that one together after a few beers :umnik2:


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## Toshi (Aug 31, 2007)

I don't know what all the fuss is about. Looks quite a simple movement to me h34r:


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## mel (Dec 6, 2006)

On a much larger scale, we called that technique "rat's nest" and used it for prototyping in electronics in the early days. It's a valid prototyping technique, allows for rapid testing and build, and once finalised, the PCB's could be designed from the prototypes. Never seen one so small though, and wouldn't like to (actually couldn't - eyes have gone) work on one as tiny as that!









Use transparent plastic (perspex) for double sided PCB prototyping, drill holes and bring connections through and back just like that example!

Best of Luck Paul

Keep us informed with

*BIG* pictures please!


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## Larry from Calgary (Jun 5, 2006)

mel said:


> On a much larger scale, we called that technique "rat's nest" and used it for prototyping in electronics in the early days. It's a valid prototyping technique, allows for rapid testing and build, and once finalised, the PCB's could be designed from the prototypes. Never seen one so small though, and wouldn't like to (actually couldn't - eyes have gone) work on one as tiny as that!
> 
> 
> 
> ...


I agree Mel. It looks like a dog's breakfast but given a schematic to work with it's probably easy to troubleshoot and fix. Looks like the PCB doesn't have any proper soldering pads so I'd bet there were a lot of cold-solder joints when these were first built.

Those definitely look like hand solder joints to me! So if there were any traces of resin left on the PCB that might be the root cause of your problem. The dial must be mounted on stand-offs so there may be mechanical (alignment?) problems as well. Not that I'm suggesting that to be the reason for it not working.

I like to see a picture of the one you're actually working on Paul.


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## JonW (Mar 23, 2005)

WOW! very very cool... It looks like the same motor as the Omega 1510, or very similar...


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## mel (Dec 6, 2006)

Larry from Calgary said:


> mel said:
> 
> 
> > On a much larger scale, we called that technique "rat's nest" and used it for prototyping in electronics in the early days. It's a valid prototyping technique, allows for rapid testing and build, and once finalised, the PCB's could be designed from the prototypes. Never seen one so small though, and wouldn't like to (actually couldn't - eyes have gone) work on one as tiny as that!
> ...


Larry, so true, your comments. A couple of thoughts - even supposing the photo was actual life size, it would still be hard to work on. I'd suspect a dry joint right away, even the piccie seems to have a couple of suspect ones, but the other problem might be those gold coloured rigid connections may have vibrated under tension over the years and be creating dry joints. Touch them with an iron or heat source and they will *spring* away from the joint and you'll never get them back into line without a spare hand or two, most of us only have the two hands!

My suspicion would be that's why Ms Longines don't want to touch them, they've tried and found this out, time wise they're BER [beyond Economic Repair - not sure if you use that term out in the colonies Larry :lol: ) and clients just won't pay the money needed for the time involved.

After seeing some of Paul's restoration projects, if anyone could do it, Paul's the man, but it ain't going to be easy, nor quick, that's for sure!


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## Silver Hawk (Dec 2, 2003)

mel said:


> Larry from Calgary said:
> 
> 
> > mel said:
> ...


Thanks Larry and Mel,

It is the size that will be the problem, I'm sure. It looks "workable on" in my posted photo but when you scale that down to the actual size, things become a little tricky. 

The other aspect is whether it is possible to test each of those transistors in-situ...or do they each need to be un-soldered to test them; something I'm not willing to do. And that is assuming I had some in-depth technical info on this movement...which I do not. 

I had an email from the owner this morning say the watch had arrived back from Switzerland and Longines had included a note saying "_No parts avail., not repairable_". Not surprising really and that shouldn't put him off...they probably swopped out modules rather than identify the root fault. Like you say, BER to them, but not to us.


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## Stuart Davies (Jan 13, 2008)

Wow looks a pigs ear to me. With so many soldered contacts it looks very fragile. Good luck with the repir Paul. One of your repair picture threads would be great


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## mel (Dec 6, 2006)

Paul, been thinking, and the problem is as you say, testing in situ without having a circuit diagram (schematic - Larry) and knowing what the transistors specs are. Very tricky indeed - the only general advice I would have is that I have only very occasionally (in nearly twenty years of discrete components repairs and design in 'tronics, hobby and pro) ever come across small signal transistors that have failed open circuit, they mostly seem to go faulty "shorted", often internally the connections get hairy and short across. h34r:

It is possible sometimes to "blow" this short away using a charged electrolytic capacitor across the offending connections, but it is only a matter of time before the short "grows" back again. Having said that, I have absolutely no idea whatsoever if this would work in/on a transistorised watch circuit without causing more damage, it's something we used to do with mainly audio and small signal devices if we had no substitute replacements  google "transistor faults" anyone who doesn't believe this









But again, we used to re-charge button cells, and reverse blast gel cell batteries with AC, and hard wire phone handsets into radio transmitters just to keep things going, it's amazing what you'll try when it's taken you an hour and a half to get to the top of a hill in a Land Rover and you don't have the right spares :yes:


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## Chascomm (Sep 9, 2005)

Yes, the Heath Robinson electronics are all very interesting, but I'd like to know what that worm-drive thingy does.


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