# Plastic Gears In The Seiko 5?!



## Ralph (Jun 9, 2006)

I was told by a Bulova saleswoman that Seiko uses plastic gears and they should be avoided! Considering I have a display back on my new "5" and can see the metal gears. Are there some hidden gears that might be plastic to save money or is this just a rumour? Condisering that Tissot had an all plastic watch around 1970 and the idea was it never needed lubrication, I'm not that concerned over this....just curious....


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## bry1975 (Feb 6, 2004)

Ralph,

Roy is the MAN to ask about movements, I've never really seen plastic gears in Seiko movements. I know a certain Swiss Firm use plastic parts.

A lot of the Seiko movements will run for 20-30years without being serviced now that's impressive. I've owned 30 year old Seikos, that were running slow, after a proper service they were always BANG on!

Seiko use in house movements, a lot of Bulova use Eta movements, not in house.

I'm sure plastic has a place in watchmaking, with it's often self lubricating properties, low mass and resistance to corrosion.

Regs

Bry



Ralph said:


> I was told by a Bulova saleswoman that Seiko uses plastic gears and they should be avoided! Considering I have a display back on my new "5" and can see the metal gears. Are there some hidden gears that might be plastic to save money or is this just a rumour? Condisering that Tissot had an all plastic watch around 1970 and the idea was it never needed lubrication, I'm not that concerned over this....just curious....


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## yak (Jun 18, 2005)

The seiko 72s6, and similar movements, use plastic gears in the day\date advancement mechanism. As Bry mentioned Lemania (swiss) also use a fair few more plastic parts in their 5100 movement which was approved for use by many armed\special forces.

These movements are rock solid and you need not worry.

Yak


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## pugster (Nov 22, 2004)

the tissot astrolon (cal.2250) is virtually all plastic , a google search should show the movement if you are interested.


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## bry1975 (Feb 6, 2004)

Plastic gears and plastic bushings are perfect in these places, where low usage is required, you also don't get the risk of seizure like you possible could with metal bushings corroding etc.



pugster said:


> the tissot astrolon (cal.2250) is virtually all plastic , a google search should show the movement if you are interested.


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## jasonm (Nov 22, 2003)

Omega used plastic gears for the day date wheels in the f300.......Unfortunatly it meshed into a metal one, for a while anyway....


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## johnbaz (Jan 30, 2005)

some rolex movements also use plastic gears (ptfe, i believe), the trouble is that when the plastic gets a coating of gunge on it, the self lubricating qualities are lost.

over the years we had loads of video players with plastic idler wheels, when they got gunged up (one of them in less than two years), they kept on ejecting the tapes as soon as you inserted it, the repair guy never cleaned the, simply threw them away and replaced them









john


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## Griff (Feb 23, 2003)

Ralph said:


> I was told by a Bulova saleswoman that Seiko uses plastic gears and they should be avoided! Considering I have a display back on my new "5" and can see the metal gears. Are there some hidden gears that might be plastic to save money or is this just a rumour? Condisering that Tissot had an all plastic watch around 1970 and the idea was it never needed lubrication, I'm not that concerned over this....just curious....





















While there is often much disdain amongst watch enthusiasts for plastic components in mechanical wristwatches, there are instances where it is acceptable and possibly even preferable. One particular area in which plastic is a perfectly logical solution is the calendar mechanism. These are parts that rotate at very slow speeds (or sometimes intermittently) and with very little torque for the majority of their rotation. This combination of features makes them controversial with regards to lubrication. While lubricating them significantly will increase the drag on the movement and possibly ultimately stop the watch, leaving them sparsely lubricated or dry will ultimately result in wear. Plastic is argued to be an ideal solution for these components because it is light and self-lubricating.

The plastic parts in question are the quickset wheels, the intermediate calendar wheel and the calendar advance wheel. The calendar advance wheel has two plastic fingers to advance the date and day disks that will easily slip out of the way if the quickset is activated while the calendar is advancing. The calendar mechanism is secured under a very thin but nicely polished metal plate that is held in place with three standard screws and one Phillips head. The presence of this one tiny Phillips screw in the movement is something of a mystery and along with the molded plastic and thin metal plates lends the bottom plate the appearance of a very well made calculator.


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## media_mute (Apr 30, 2006)

http://members.iinet.net.au/~fotoplot/tissot/tissot.html

here's a cool link to the tissot movement


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## Isthmus (Sep 29, 2005)

Ralph said:


> I was told by a Bulova saleswoman that Seiko uses plastic gears and they should be avoided! Considering I have a display back on my new "5" and can see the metal gears. Are there some hidden gears that might be plastic to save money or is this just a rumour? Condisering that Tissot had an all plastic watch around 1970 and the idea was it never needed lubrication, I'm not that concerned over this....just curious....


Your mistake was taking the saleswoman seriously. Salespeople at jewellery store and watch retailers tend to be notoriously misinformed about their own product. Heck in my experience I would go as far as to say unknowlegable. Sure, on occasion you might get one who knows what they are talking about, but they tend to be few and far between - and when you get that knowledgable person, often times they are either a jeweller or a watchmaker.


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## marius (Mar 11, 2005)

Isthmus said:


> Ralph said:
> 
> 
> > I was told by a Bulova saleswoman that Seiko uses plastic gears and they should be avoided! Considering I have a display back on my new "5" and can see the metal gears. Are there some hidden gears that might be plastic to save money or is this just a rumour? Condisering that Tissot had an all plastic watch around 1970 and the idea was it never needed lubrication, I'm not that concerned over this....just curious....
> ...


..or a carburettor saleslady! Pretty she was too. Worked behind the counter at the Bosch shop at Lion Bridge.







I dont believe anyone will ever know as much as she did about jetting!









On a more serious note, I have always found that there is an issue with plastic. It's the name. If they started calling it what it really is, poly-amide, or poly propylene, (or poly-tetra-fluoro-ethelene!)people are not so negative about it. Who would buy a bike or race car with a plastic chassis? Poly-carb is good though.

"Plastic" outperforms metal in many applications, as long as it is the right "plastic".


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## Ralph (Jun 9, 2006)

Hmm, interesting info, thanks guys. I read that Ford built an engine entirely out of plastic some years ago, and it doesn't melt! Of course this was experimental, but if true it's amazing what can be done with plastics and I am not concerned over a couple of waych gears made of it then.


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## johnbaz (Jan 30, 2005)

marius said:


> Isthmus said:
> 
> 
> > Ralph said:
> ...


don't forget the other one-* polly-putthekettleon*









*ralph*, i heard that some car companies make engines fully of ceramics and they out-perform traditional iron/aluminium etc 

john.


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