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Discussion Starter · #1 ·
I can't believe what I just read.
Does my Hamilton Jazzmaster Auto Chrono Valjoux 7750 from 2009 have plastic movement parts???!??!
Or is this when ETA took over Valjoux (a company? or just the name of the movement?)

Who can clarify this for me and what about other movements especially chronographs...
What about the modified eta based movements?

They dont specifically speak of my jazzmaster having plastic parts but theyre talking about the 7750 movement!

read in this thread https://www.watchuseek.com/f2/new-eta-chrono-movement-c01-211-good-news-bad-news-159561.html

Hope to learn the truth ;)
 

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IIRC 7750 indeed have plastic parts - plastic brake and one bearing. Why you are so upset? It's not bad at all. Even Omega 861/1861 movement has plastic brake. They are durable, does not need lubrication.
 

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Discussion Starter · #3 ·
The Valjoux 7750 Chronograph - Part 1 - TimeZone
part two The Valjoux 7750 Chronograph - Part 2 - TimeZone

What a dissapointment to find this out!!!

Yes i am quite upset thinking that I have a quality (in my own perception of quality ;)) Swiss movement, an automatic mechanical movement. just finding out that it has plastic parts working. Due to cost reduction they use plastic parts and nothing else, if it has so many benefits the plastic why dont they produce a complete movement of plastic parts then... why not, because its in the long run not durable.

My thoughts for now is if I really do have a genereation Valjoux 7750 with plastic bearing and brake, can I ask my watch maker to change these plastic parts for - (the plastic brake) metal one and (the bearing) for a jewel. How much this would cost me to realize is what I would have to find out.

For the ones that didnt open the article first here the pics of the movement.




So can anyone enlight me, does my Valjoux 7750 from 2009 (bought dont know when manufactured) have plastic brake and bearings??? I can also wait 1 year to find this out cause then the service is due and can ask my ad to ask Hamilton to check my movement for plastic parts (if there are any)
Rather I would like to hear from you guys if I do have plastic parts in my movement for this generation valjoux.
 

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DLXXV I agree this is just cost cutting and it stinks. I just purchased a new Vostok K34gmt Auto and it has no plastic parts .
 

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I don't think it's necessarily only for cost cutting. From what I read, quite a few movements use plastic parts deliberately because of the benefits of plastic for whatever function that specific part serves.
For example, this poster said Delrin (plastic/nylon) parts were used in the famous Lemania 5100 because of its strength and self-lubrication. The Lemania 5100 was supposed to be quite rugged, durable and was specifically used for military applications such as by Sinn and Fortis. I believe this partially was due to the use of Delrin parts.

And lysanderxiii, a knowledgeable watchmaker here, also commented on the use of plastic parts in the 7750:
https://www.watchuseek.com/f2/$5000-eta-based-watches-710470-11.html#post5186275
I just love when people know know little about a movement engineering make comments about the engineering choices made...

The choice to use a plastic bearing in the second wheel is the proper one. First, that "bearing" isn't really a bearing, per se, it is a friction spring to keep the second hand from stuttering. Many other major movement with independent second hands use just a simple metal spring to do this job, but there is a fine line in having the required tension to suppress the stutter, and having too much tension and causing a amplitude shift in the movement. The plastic washer makes for a better tensioner, and is also self-lubricating.

The plastic brakes for the second wheel and hour wheel. They grip without slipping, what can I say?

Well, I can say that the Chinese copy of the 7750 decided to replace these "horrible plastic things" with nice metal brakes. Guess what, Chinese 7750 tend to slide the hour hand when the stop button is pushed.

Just because you see plastic it does not automatically equal "cheap".

By the way, a Sea Gull 1903 column wheel chronograph has a crisper button push than a 7750 (or 7734), but I wouldn't pick a 1903 over a 7750 if quality, workmanship and accuracy were my criteria for excellence....
 

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Discussion Starter · #7 · (Edited)
I don't think it's necessarily only for cost cutting. From what I read, quite a few movements use plastic parts deliberately because of the benefits of plastic for whatever function that specific part serves.
For example, this poster said Delrin (plastic/nylon) parts were used in the famous Lemania 5100 because of its strength and self-lubrication. The Lemania 5100 was supposed to be quite rugged, durable and was specifically used for military applications such as by Sinn and Fortis. I believe this partially was due to the use of Delrin parts.

And lysanderxiii, a knowledgeable watchmaker here, also commented on the use of plastic parts in the 7750:
https://www.watchuseek.com/f2/$5000-eta-based-watches-710470-11.html#post5186275
Thank you Citizen V for this quote of lysanderxiii
Its enlighting, but in any case what I can make out of the acrticle that I posted and also agreed upon in the $5000 ETA-based Watches is that the 7750 is mainly made to be cost efficient... so it can be used in many watches of today. I can now live with the fact that I bought an automatic knowing that it was designed for cheap cost effective production of movements.

My next watch purchase will be a more extensive researched designed movement one hoping to get the best of the best that is in my own opinion the best;)

Eventhough it (my Jazzmaster Auto Chrono Valjoux 7750) is a great first automatic and wouldnt coonsider selling it, just live and learn, another story to be told about thia particular watch... next watch not gonna be a Valjoux 7750 though

to alexwatch: Gonna check out the Vostok perhaps my next watch?
edit: not my kind of design alexwatch;)
 

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I'm glad for the plastic parts. . . because I don't think it can possibly be a cost-cutting decision, and, therefore, must be solely an engineering one.

Think about it.

First, do you really think that the cost savings of plastic over steel on these parts, given the volume of 7750 movements made and subsequent economies of scale, can really be that large?

Second, if it the savings are that significant and that is what is important to ETA, then why only the 2 parts? There are any number of other things that could easily be made using plastic, many of which would have literally no effect on the performance of the movement. The index, for example - a simple shaped part that you probably aren't even moving once a year.

The 7750 has 111 parts and has been around since 1974, and in all that time they've only decided to use plastic for 2 parts? 2 small parts, that aren't even complex? The brake is just as easy to stamp out of metal as it is to mold from plastic -- might even be easier, actually, as stamping is likely to produce less defects.

DLXXV, you said, "to cost reduction they use plastic parts and nothing else, if it has so many benefits the plastic why dont they produce a complete movement of plastic parts then... why not, because its in the long run not durable." But I just don't think the logic works. If cost reduction were that important, why care about durability? Why not make something cheap that people will then buy over and over again? I think there are absolutely benefits of plastic, when used appropriately (and lysanderxiii, at least, seems to think they are).

To me the attention to detail to evaluate each and every one of the 111 pieces individually and to individually figure out and decide what material is the appropriate one is a mark of quality and one that I, personally, appreciate.
 

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I know nothing about the construction of a watch movement. But I think you need to sit back and relax and let the experts in the field do the designing and worrying about your movement. One only has to look to the automotive manufacturing industry as an analogy- is Mercedes, BMW or Ferrari any lesser of a product because they use plastic parts? You could look at almost anything that is manufactured and designed this way- they're always looking at ways to "better" the process and the product. You have a warranty period and your watch will outlive you. Companies that get it wrong are destined to fail.
 

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This is the problem when you outsource it is very hard to find in house movements therefore you accept less. My Rolex air king has no plastic and older Hamiltons don,t.
 

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This is the problem when you outsource it is very hard to find in house movements therefore you accept less. My Rolex air king has no plastic and older Hamiltons don,t.
And yet older Omegas do, and one of the Speedy Pros still does (one with hesalite crystal and solid caseback). They do replace the Delrin brake with an arguably inferior metal brake if you get a display caseback...
 

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Discussion Starter · #12 · (Edited)
What I understand now is that the Valjoux 7750 is designed to be a cheap way to built an automatic movement that is in the basis a reliable one.
To prove this that it is designed to be cheap to manufacture see the following pic:


"Another cost-saving design approach is seen in the mainspring click. Rather than use a conventional click to prevent mainspring unwind, Valjoux has managed to use a simple bent spring anchored in a slot in the plate."

Why is it that it is used (the Valjoux 7750) in so many watches, yes because it is a cost effective way to produce an automatic movement. Yet it has proven itself to be also a reliable one when serviced properly. I am content with the Valjoux 7750, it would have been otherwise not possible for me to buy an automatic chronograph just as easily as now (would have saved up much more than what I paid for) that is the case for many owners of automatic chronographs. But as I said I wouldnt settle for less than the best in my next auto chrono movement purchase.

note: I dont want to offend other Valjoux 7750 owners, or bring them down in any way but these are the facts and I can live with it. Am also not planning to sell mine. Dont pretend a workhorse to be a prancing horse when it is not, yet its not a donkey ;), what I want to say is that it is still a complex movement.
 

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I think you've reached the correct conclusion that the 7750 is a nice workhorse movement. With proper care it can last a lifetime, and with some higher grade finishes it can represent very nice workmanship.

Even at base grade, I think the 7750 movement is worth every penny of its $350 grey-market price.--partially because it can be serviced so readily.

How much did you spend on your watch? Unless you spent more than $1500 I think it's very reasonable for your watch to use this 7750 movement. Once you add a case, dial, hands, crystal, strap, ... all worth $300+ in parts, plus labor, warranty, etc. It's a good value.

And there's no reason to be upset about ETA's desire to reduce manufacturing cost. They reduced their cost, but managed to build a machine that can run a lifetime with proper maintenance. In my opinion, the cost saving measures did not sacrifice functionality or quality. Now if they shaved their costs like Chrysler shaves theirs, I'd be upset. :D

On a side note, I personally would not spend that much for a 7750 based watch. if I'm going to spend $1500+ it better be a spring drive or co-axial. (yeah it'll have to be used...)
 

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I don't think it's necessarily only for cost cutting. From what I read, quite a few movements use plastic parts deliberately because of the benefits of plastic for whatever function that specific part serves.
For example, this poster said Delrin (plastic/nylon) parts were used in the famous Lemania 5100 because of its strength and self-lubrication. The Lemania 5100 was supposed to be quite rugged, durable and was specifically used for military applications such as by Sinn and Fortis. I believe this partially was due to the use of Delrin parts.
Quite true. Delrin(TM) is pretty awesome. Delrin's durability and self-lubricating qualities have made it the go-to material for many applications. In fact, Delrin is more expensive than many metals, though cheaper than super alloys.
 

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But as I said I wouldnt settle for less than the best in my next auto chrono movement purchase.
Then be prepared to spend five or even six figures (I'm talking USD here).

Owners of 7750s and Omega Speedmasters can pointlessly have those plastic parts replaced with inferior and shorter-lived metal ones at considerable cost if they wish. It will, though, make the movement *just* slightly worse but apparently that is what they want!
 

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I think there is a Shakespeare play about the objection over the use of plastic... yes there is - Much Ado About Nothing :-d

BTW, the Lemania 5100 is a much more durable movement and is capable of working under conditions that will freeze the 7750 (4 G turns for example). It has always had plastic parts where plastic made sense. As other posters said, it is just good engineering.
 

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It has cheap synthetic rubies too...

Sent from my SCH-I535 using Tapatalk 2
 
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