Service the A7750 ..

[801run]

I have a Link Chrono (A7750 28k8) that seems to be in need of service in the near future. I'm thinking of servicing it myself just for fun and perhaps to learn something. Is it very important to use all these different oils on different parts, or is it possible to go for i.e. moebius 8200 on all parts? Also, do you have to take the movement completely apart and oil each part, or, this is probably a stupid question, could you simply put the complete movement in a jar with some kind of chemical dispersing all old grease and oil, then taking it out and let it dry, then try to reoil the movement by putting oils on all visible parts of gears and stuff and getting the movement going to spread the oil to inner parts in the movement?

On the other hand, is it worth the effort or should I simply go for a new A7750 replacement movement? Have no idea if those are hard to get though, or how they are priced? Maybe I should throw my dealer a question.

Also, have a Carrera with the old A7750, want to switch to a new high-beat A7750 but am aware of the problem with different sized hand post. Have somebody managed this switch? Is it possible to simply glue the hands (really hard to get this right I guess) onto the smaller posts?

Regards,

801run

Edited January 6, 2009 by 801run

[b16a2]

Firstly if you are unsure about servicing a movement, don't try it. Especially with the 7750. Try buying a cheap 21j asian movement and experimenting on those first, then work your way up.

When you say in need of a service in the future, has it started to 'misbehave' or is it something that you wish to do for piece of mind?

Also it depends on how much you spent on the watch. A service will typically cost from 150USD upwards (guestimate), so it depends whether you think that spending such an amount is proprtional to buying a new one. One thing I will say is that once the A770 is serviced it should run smoothly for at least 4-5 years before needing another service. So do you see yourself wanting to keep this watch runnig for a decade, or just as something for a few years to wear?

I appear to have created more questions than I have answered

[mjmurphy926]

The Zigmeister is the master watchsmith around here. Spend some time reading his awesome tech posts:

http://www.rwg.cc/members/index.php?showforum=209

This one inparticular answers most of your questions:

http://www.rwg.cc/members/index.php?showtopic=78016

[Toadtorrent]

I've written this elsewhere...but servicing will cost $200USD + shipping + parts if required. You can do preventive maintenance servicing as recommended by The Zigmeister at around the 9mos mark and you'll avoid wearing down parts, and make the movement reliable for likely 5 years or so before the next servicing...or you can let it die...and do a movement replacement at $150 CDN or so for the movement plus $100 USD for the movement swap...or learn to do it yourself.

Do a movement swap the first time will likely involve you losing screws, bending arms, leaving fingerprints around where they shouldn't be, losing a spring, etc...and requires an investment in some tools.

Don't think you'll be able to break down an A7750 movement successfully with the potential for rebuilding it the first time you dig into a watch. You WILL destroy the movement and you won't be able to source parts. Start small. Try a removing and reinstalling hands. Try decasing...try a datewheel swap, etc...an A7750 is extremely complex...and not for the faint of heart or lacking in proper tools and ability to work using a loupe.

[801run]

Firstly if you are unsure about servicing a movement, don't try it. Especially with the 7750. Try buying a cheap 21j asian movement and experimenting on those first, then work your way up.

When you say in need of a service in the future, has it started to 'misbehave' or is it something that you wish to do for piece of mind?

Also it depends on how much you spent on the watch. A service will typically cost from 150USD upwards (guestimate), so it depends whether you think that spending such an amount is proprtional to buying a new one. One thing I will say is that once the A770 is serviced it should run smoothly for at least 4-5 years before needing another service. So do you see yourself wanting to keep this watch runnig for a decade, or just as something for a few years to wear?

I appear to have created more questions than I have answered

Thanx for the quick reply!

Actually it hasn't started to misbehave at all, I'm just having the feeling that perhaps it would be a good idea for a service since they are unserviced from the factories (as i've been told), or when I really do need to service it due to misbehaviours, whether it will be worth it or to go with a new movement. I have an 21j asian in a cheaper rep that is just waiting to be toyed with, so I will take your advice there!

I love the watch! Want to keep it alive for as long as I can, a decade at least =)

[801run]

The Zigmeister is the master watchsmith around here. Spend some time reading his awesome tech posts:

http://www.rwg.cc/members/index.php?showforum=209

This one inparticular answers most of your questions:

http://www.rwg.cc/members/index.php?showtopic=78016

Thanx for the links, looked around at a few earlier but seemed to have missed the one with oilings. Learned a lot in 5mins there =) Now I understand that the oil goes into the pivots and why I can't "distribute it" by oiling the gears .. it's pretty obvious when you think about it since thats were you have most of the friction.

[mjmurphy926]

Glad to help.

[Fireman_Fred]

I have recently come to the conclusion that if you have a rep that you intend to keep it is definately worth paying to get it serviced. Yes, I know it seems like a large expense on a watch that may have only cost $250 - $300 but I'm sure it is more cost effective than waiting for the movement to "die" and then having to go through the hassle (and expense) of replacing it, every 1 - 2 years.

I am now getting my favourite watches properly serviced (by a time served, respectable watchmaker) and hope to enjoy wearing them for a few years to come.

[801run]

I've written this elsewhere...but servicing will cost $200USD + shipping + parts if required. You can do preventive maintenance servicing as recommended by The Zigmeister at around the 9mos mark and you'll avoid wearing down parts, and make the movement reliable for likely 5 years or so before the next servicing...or you can let it die...and do a movement replacement at $150 CDN or so for the movement plus $100 USD for the movement swap...or learn to do it yourself.

Do a movement swap the first time will likely involve you losing screws, bending arms, leaving fingerprints around where they shouldn't be, losing a spring, etc...and requires an investment in some tools.

Don't think you'll be able to break down an A7750 movement successfully with the potential for rebuilding it the first time you dig into a watch. You WILL destroy the movement and you won't be able to source parts. Start small. Try a removing and reinstalling hands. Try decasing...try a datewheel swap, etc...an A7750 is extremely complex...and not for the faint of heart or lacking in proper tools and ability to work using a loupe.

Thanx for the figures toad! I'm sure you're right, I would break it for sure. I've just started with this rep-business and I'm completely into it and can't wait to start taking things apart! =) Love this forum with all the knowledge! I have some tools coming in now which will be needed, but I've already done some basic stuff without any tools, like taking the movement out, popping the crystal and having it AR:ed then replaced it with the thumbs (that was pretty difficult actually, but it worked), really liked the result though (on a Carrera, greenish-yellowish tint kind of AR performed at local lab). Havn't removed the dial yet though, need the hand removal tools and stuff for that first. But that will be the next step I think.

I guess that doing a complete service of the movement also means you have to reregulate and adjust the movement, and I guess that can be hard to do without the machines watchsmiths often use?

Anyway, having looked at quite a few of The Zigmeisters and others posts, I havn't found a _complete_ quide to servicing i.e. a A7750 movement. Is there such a guide available, like a step-by-step tutorial? Would really appreciate it if someone had I link for such a thing ..

[801run]

I have recently come to the conclusion that if you have a rep that you intend to keep it is definately worth paying to get it serviced. Yes, I know it seems like a large expense on a watch that may have only cost $250 - $300 but I'm sure it is more cost effective than waiting for the movement to "die" and then having to go through the hassle (and expense) of replacing it, every 1 - 2 years.

I am now getting my favourite watches properly serviced (by a time served, respectable watchmaker) and hope to enjoy wearing them for a few years to come.

Interesting! I would like to be able to do the same, but I doubt there is a local watchsmith capable of such things. Perhaps it's worth it to send new reps directly to i.e. The Zigmeister (if he offers this service, havn't talked to him), but it would be so nice to be able to do it yourself, since I'm already on my 5th rep after like 3 months when I started this, I would have some money to save by being able to do this myself.

[RWG Technical]

If you want to it yourself, contact member Offshore and buy his CD with the Time Zone watchmaking school course.

The 7750 is a very complex and difficult movement to service, as your first attempt for servicing you will ruin the movement. You have to start with the basics, and the TZ course is the way to go. Tooling alone will run into the $1000's of dollars, and you need many many hours of practice to have the skills for watchmaking.

RG

[801run]

If you want to it yourself, contact member Offshore and buy his CD with the Time Zone watchmaking school course.

The 7750 is a very complex and difficult movement to service, as your first attempt for servicing you will ruin the movement. You have to start with the basics, and the TZ course is the way to go. Tooling alone will run into the $1000's of dollars, and you need many many hours of practice to have the skills for watchmaking.

RG

Thanx for the tip The Zigmeister! Think I will contact him and buy the CD even if I decide not to do it myself, it would be interesting just to read and learn. I'm sure its quite complex, all those tiny tiny springs scares me the most i think, it must be a hazzle to get them back into place once disassembled. Also, I've tried to regulate (think that is the term, not adjusting which is the more complex process?) couple of A7750s that were running to fast, and only this task is very tideous and sort of trial-and-error process, without machines at least. So, maybe I'll skip this afterall. In the guide, are there tips to where you can by oils and tools and what oils to use etc? Well, I guess I'll find that out when I buy the guide

Thanx a lot all you guys! Really love this forum and the helpfullness and responsiveness of you all!

[tfbit]

Check out the link in this thread at repgeeks for complete disassembly and assembly diagrams from ETA. It is a little amazing. Make sure you check out the adjustments section at that site also. Seeing stuff like this makes me want to try it also, but If I liked the watch at all, I think I would pay an experienced person to do it.

http://www.repgeek.com/showthread.php?t=35267

Link if you don't have a repgeeks account:

http://pugwash.info/eta/7750/7750.html

[Toadtorrent]

Thanx for the tip The Zigmeister! Think I will contact him and buy the CD even if I decide not to do it myself, it would be interesting just to read and learn. I'm sure its quite complex, all those tiny tiny springs scares me the most i think, it must be a hazzle to get them back into place once disassembled. Also, I've tried to regulate (think that is the term, not adjusting which is the more complex process?) couple of A7750s that were running to fast, and only this task is very tideous and sort of trial-and-error process, without machines at least. So, maybe I'll skip this afterall. In the guide, are there tips to where you can by oils and tools and what oils to use etc? Well, I guess I'll find that out when I buy the guide

Thanx a lot all you guys! Really love this forum and the helpfullness and responsiveness of you all!

The issue is...without having someone teach you the "feel" of things...you will make mistakes. And for anybody serious about watchmaking, they would NOT learn on something as complex as an A7750. It's kind of like saying you want to learn about gas powered engines, so you bought a book and want to start with your Porsche Carrera GT.

You start small...with a lawn mower maybe...learn the basics of operations with simple no date, non-chrono movements just to get used to working under magnification, etc before you add the complications. Search around for the number of posts for people who have screwed up their movements just trying to get their stems back in. AND...if you don't have spare screw kits...and you lose one...you're pooched. A7750 movements don't have spare parts suppliers.

Believe me...I want to learn too...but I'm not about to learn on a $150 movement that I will most guaranteed destroy. I've started on cheap $12 movements to get used to working with tweezers and magnification on simple stuff...and to understand basic operations. I'll dive into a chrono when I have a movement that's died.

[801run]

The issue is...without having someone teach you the "feel" of things...you will make mistakes. And for anybody serious about watchmaking, they would NOT learn on something as complex as an A7750. It's kind of like saying you want to learn about gas powered engines, so you bought a book and want to start with your Porsche Carrera GT.

You start small...with a lawn mower maybe...learn the basics of operations with simple no date, non-chrono movements just to get used to working under magnification, etc before you add the complications. Search around for the number of posts for people who have screwed up their movements just trying to get their stems back in. AND...if you don't have spare screw kits...and you lose one...you're pooched. A7750 movements don't have spare parts suppliers.

Believe me...I want to learn too...but I'm not about to learn on a $150 movement that I will most guaranteed destroy. I've started on cheap $12 movements to get used to working with tweezers and magnification on simple stuff...and to understand basic operations. I'll dive into a chrono when I have a movement that's died.

Yes, I understand that I have to get a feeling for it first, and I don't think I underestimate the complexity of the A7750, IF a try it, i will be prepared that I WILL destroy the movement. But since I really like this new hobby of mine I just might be prepared to buy an A7750 movement to try on, and when I fail I can at least use some of it for spare parts in the future (hopefully). I have an Asian 21j that I will start with, also perhaps buy the the ETA2836 and use that together with the TZ school to learn as well. But I also have the same feeling that you have, WHEN any of my A7750 watches die, THEN I will try it, it is as you say not a cheap movement just to toy with and I don't really need to do this now .. but in the same time, I've got the feeling that I will not be able to stop myself from this =) Also its a good feeling to know your movement has been oiled and hopefully will run for 5 years before reoiling instead of stopping after 1-2 years due to tear-down (someone said 1-2 years is probably what to expect with an unoiled A7750 movement, agree?).

I need to get a bunch of tools though, I will probably go for most of the tools in the TZ toolkit. However, I think you don't need to cough up $90 for the Bergeon screwdriver set, I can get good screwdrivers for a lot less than $90, also $50 for two Bergeon tweezers seem a little much, so there has to be some money to save at least for the "standard" tools.

Will not buy a timing machine to start with, then my girlfriend would probably call the men in the white coats =) What bugs me is that I've made a simple computer program that analyzes a wave file and count the tick tock's from a movement (I'm a programmer), and I've tried it on sample wave files downloaded from sites that sell the commersial programs, and my program seems to work well, but I can't find a good enough mic! I've only tried one yet, but it wasn't sensitive enough .. if I'm just able to get hold of a mic, then the program would save me lots of trail-and-error time. Don't suppose anyone has a hint for me here regarding mic?

Also I will probably get the ETA7750 guide from offshore.

Btw, someone (The Zigmeister perhaps?) know if there is any difference in the level of complexity to perform service on a old low-beat A7750 compared to the new high-beat?

[801run]

Check out the link in this thread at repgeeks for complete disassembly and assembly diagrams from ETA. It is a little amazing. Make sure you check out the adjustments section at that site also. Seeing stuff like this makes me want to try it also, but If I liked the watch at all, I think I would pay an experienced person to do it.

http://www.repgeek.com/showthread.php?t=35267

Link if you don't have a repgeeks account:

http://pugwash.info/eta/7750/7750.html

WOW! Amazing link tfbit! I've been looking around for something like that but never found it! Thank you very much!!

Is this perhaps the same guide as the ETA7750 guide that offshore offers?

[Toadtorrent]

WOW! Amazing link tfbit! I've been looking around for something like that but never found it! Thank you very much!!

Is this perhaps the same guide as the ETA7750 guide that offshore offers?

When Offshore offered his, it was bundled with a whole pile of documentation...A LOT of stuff including the courses, and stuff that The Zigmeister and others had contributed to the kitty as it was done as a bit of a fundraiser for the forum.

I have it...haven't worked my way through that much of it.

With the screwdrivers...mine aren't that expensive. You'll find you'll have to sharpen and straighten the cheaper ones more regular because of the cheaper material used...not a big deal if you aren't using them all the time...but if not careful, you could damage the heads very easily. The small work surfaces make the effect of errors more pronounced.

There are computer programs like you said that can act as a vibrograph...the issue was getting a mic and environment that can pick up the sound of the movement properly. They're an expensive tool to start with...but REQUIRED IF you do a complete strip down.

I want to get into it one of these days. If you look at my Guide to the Crazy Hours movement in my signature, it has a picture of a sort of basic starting toolkit (not complete) used to remove hands, reset, decase, etc.

[RWG Technical]

I don't suggest you start with any asian automatic movement, your sure to throw it against the wall in frustration and give up hope.

These models have one big honking bridge that covers every gear and pivot, next to impossible to assemble, I don't waste my time on these, much too frustrating.

The 2836 series is a great starting point by following along with the TZ course. 20-30 teardowns and assemblies and you get the feel for how it all works, and then with the help of the ETA teardown PDF docs, you can tackle a 7750.

RG

[Toadtorrent]

I don't suggest you start with any asian automatic movement, your sure to throw it against the wall in frustration and give up hope.

These models have one big honking bridge that covers every gear and pivot, next to impossible to assemble, I don't waste my time on these, much too frustrating.

The 2836 series is a great starting point by following along with the TZ course. 20-30 teardowns and assemblies and you get the feel for how it all works, and then with the help of the ETA teardown PDF docs, you can tackle a 7750.

You're right of course. There's no documentation or training on the Asians which is a definite strike against working on them. I was just thinking in terms of cheapness to get used to using the tools and working using a loupe which is an art in itself. I realized quickly why the good tools are anti-magnetic...not like the cheap ones I initially purchased.

[801run]

I don't suggest you start with any asian automatic movement, your sure to throw it against the wall in frustration and give up hope.

These models have one big honking bridge that covers every gear and pivot, next to impossible to assemble, I don't waste my time on these, much too frustrating.

The 2836 series is a great starting point by following along with the TZ course. 20-30 teardowns and assemblies and you get the feel for how it all works, and then with the help of the ETA teardown PDF docs, you can tackle a 7750.

RG

Thanx Rob. I'll probably skip the A21j then and go straight onto the 2836 with TZ course. When you say that the asian automatic models have this big honking bridge which make them hopeless, doesn't that include the A7750 also then? Or is the A7750 pretty similar to the ETA7750, so you would be able to follow the ETA guide at least for the most parts? How about the asian 2836, is that similar to the ETA2836 so I would be able to use that instead of the real deal when taking the TZ course, or does it also have this big honking bridge perhaps ..

Thanx again for all info.

[801run]

When Offshore offered his, it was bundled with a whole pile of documentation...A LOT of stuff including the courses, and stuff that The Zigmeister and others had contributed to the kitty as it was done as a bit of a fundraiser for the forum.

I have it...haven't worked my way through that much of it.

With the screwdrivers...mine aren't that expensive. You'll find you'll have to sharpen and straighten the cheaper ones more regular because of the cheaper material used...not a big deal if you aren't using them all the time...but if not careful, you could damage the heads very easily. The small work surfaces make the effect of errors more pronounced.

There are computer programs like you said that can act as a vibrograph...the issue was getting a mic and environment that can pick up the sound of the movement properly. They're an expensive tool to start with...but REQUIRED IF you do a complete strip down.

I want to get into it one of these days. If you look at my Guide to the Crazy Hours movement in my signature, it has a picture of a sort of basic starting toolkit (not complete) used to remove hands, reset, decase, etc.

Thanx toad! Will check your guide and the toolkit, always nice to compare different kits to get the feeling for what tools you MUST have, and what you might be able to do without =)

I'll buy the guides from offshore anyway, since you say there is more documentation to the ETA7750 guide and also since I'll then be supporting the forum.

One thing I reacted on when stepping through the ETA7750 flash guide .. I always had the feeling that the balance wheel, balance spring and [censored] and all those parts of the balance would be the most tricky in (dis)assembling a movement. Don't know why I had that feeling since I've never taken a movement apart =) .. anyway, in the guide, the just lift out the whole balance as one piece, describing it as though you normally do not disassemble it? I wonder if it HAS to be disassembled in order to perform a good service, or if it can be simply cleaned and oiled as a whole, as they indicate in the flash guide when assembling the movement again. I will probably be able to read about that in the ETA7750 docs though.

Cheers!