Nick Hacko, I have the answer for you>>>

[Jocke]

I just talk with a Rolex trained watchmaker and he
told me the "dummy jewel" is to support the date wheel
when it change date. I suppose it will slide a
little when it change date.

Does that sounds ok in your ears?

I hope that because the guy I know is one of the best when
it comes to Rolex movements.

Jocke

[SPACE-DWELLER]

Cool, Jocke

[Ironstark]

From what you describe the "dummy" jewel as you call it, is probably the jewel set into the calender plate. The date indicator (or disc) sits in a recess and this jewel is set into the edge of this recess. It is there to reduce side shake and for the disc to work/slide against when it jumps. There is far less friction between the edge of the disc and the jewel than there would be between it and the calender plate itself.

[Nick Hacko]

Hi Jocke -

this would be the most logical answer HOWEVER the date disc does not come in contact with
dummy jewel at all, at any time - see my original post. Thanks for your help anyway and
regards to your watchmaker friend.

[Paulie]

Here's a link to the original thread Nick made, with pictures:

http://rolexforums.com/showthread.php?t=20603

[Ironstark]

The date disc edge DOES contact the jewel during operation otherwise there would be no reason for it to be there.!?! When the disc is flicked foreward by the date wheel finger the rotational force applied will cause the disc to move out towards the edge of the recess. In order to ensure it does`nt hesitate there or move too far out of position the jewel acts as a movement limiter when it contacts the edge of the date disc.
It does not stay in contact with it but they do touch.

[Nick Hacko]

Originally Posted by Ironstark

From what you describe the "dummy" jewel as you call it, is probably the jewel set into the calender plate. The date indicator (or disc) sits in a recess and this jewel is set into the edge of this recess. It is there to reduce side shake and for the disc to work/slide against when it jumps. There is far less friction between the edge of the disc and the jewel than there would be between it and the calender plate itself.

If that is the case then 1. dummy jewel is situated about 90-120 degrees away from where it should be (as close as possible to 'pin' on date change wheel. 2. there is no enshake because date disc is constantly under tension (toothed spring). 3. Thanks to this spring, almost half of the disc is rubbing against date plate anyway. Based on that alone, reducing drag and friction at microscopic contact surface between
disc / jewel and date plate would be pointless.

I think we need to think here outside the square. Thanks for taking time to respond.

Originally Posted by Ironstark

The date disc edge does contact the jewel during operation otherwise there would be no reason for it to be there.!?!
It does not necessarily stay in contact with it but they do touch.

Reverse logic. Just becuse it's there it does not mean it is needed. This is the point I am trying to make.

[Ironstark]

Originally Posted by Nick Hacko

If that is the case then 1. dummy jewel is situated about 90-120 degrees away from where it should be (as close as possible to 'pin' on date change wheel. 2. there is no enshake because date disc is constantly under tension (toothed spring). 3. Thanks to this spring, almost half of the disc is rubbing against date plate anyway. Based on that alone, reducing drag and friction at microscopic contact surface between
disc / jewel and date plate would be pointless.

I think we need to think here outside the square. Thanks for taking time to respond.



Reverse logic. Just becuse it's there it does not mean it is needed. This is the point I am trying to make.

I need to think outside the box ?!?.
The force applied by the date jumper (sorry toothed spring) is and has to be less than that applied by the date finger, date yoke and its spring otherwise the date would not change at all!!! The force of the date yoke spring coupled with the disc`s own inertia will cause the disc to travel far enough to contact the jewel. I have seen slow motion footage of this in Geneva, have you? It does not always contact it but it can and does happen. Position will have something to do with it etc.. As I said it`s main function is to act as a movement limiter for the disc to ensure it does not move too far out of position during changeover.
I DONT appreciate your patronising tone.
You asked the question at the beginning, what was its function? You stated you are not Rolex trained. You wanted the opinion of a Rolex trained watchmaker (you even listed my name in the original post as one of the people who might give an answer), you got that but you dismiss the answer given.
Why bother asking the question if you are not interested in the answer? Or are not willing to accept another opinion.
Incidentally, if you look under the three polished steel maintaing studs ( sorry holders) at 9, 6ish and 4 in your picture ,you will find three more jewels!

Just because YOU cant see why its there, does`nt mean it not needed!

[Lol-x]

Thanks Ironstark for your knowledge. I merely believed that there had to be some degree of contact between the jewel and the date wheel.

[rolex5]

In the eyes of an untrained-rookie, I believe that the fourth jewel is there for the purpose of decoration. j/k.

Just try to cool things down & Thursday is almost over.

[Ironstark]

Not almost enough.

[rolex5]

Almost is not equal to enough.

[Nick Hacko]

Originally Posted by Ironstark

The force applied by the date jumper (sorry toothed spring) is and has to be less than that applied by the date finger, date yoke and its spring otherwise the date would not change at all!!!

This is obvious and not relevant.

Originally Posted by Ironstark

The force of the date yoke spring coupled with the disc`s own inertia will cause the disc to travel far enough to contact the jewel. I have seen slow motion footage of this in Geneva, have you? It does not always contact it but it can and does happen.

No I havn't! However I am very pleased that I have obser with naked eye something so extremly rare that would need to be fimed in played in slowmotion to Rolex watchmakers as proof of it's existance. WOW !

Originally Posted by Ironstark

I DONT appreciate your patronising tone.

??

Originally Posted by Ironstark

You stated you are not Rolex trained. You wanted the opinion of a Rolex trained watchmaker

I was hoping Rolex trained watchmaker could provide more convincing evidence that I could provide myself. As stated in OP, I have limited access to Rolex techincal information re. 31xx.

However since you may have limited access to watches made by other manufacturers, I reserve right to further analyze your answer. Unless you say because you are Rolex trained you are less biased then me?

Those with better memory would remember that few months ago
we had discussion whether the 16613 crown is made out of solid 18K gold or not.
Despite all evidence provided, you still called the crown "monobloc"
refusing to accept obvious.
http://rolexforums.com/showthread.php?t=16263&page=1

Although I find your opinion(s) slightly biased I truly enjoy your
public responses for which I thank you.

Finally - and most importantly - the calendar wheel was not invented by Rolex. It has been around in it's current form for at least 600 years, "invented" by German clockmakers. Every single thinking maker since then is trying to solve the problem of friction between date wheel, date disc and it's support.

[C.J.]

O.K., guys. Haven't we had enough in the way of grief over the past week or so? Let's just move on with this one, shall we, please. You're both quite competent at what you do and your input and expertise is appreciated here, very much. But, let's not beat this one issue to death here. Can't you just simply agree to disagree and move on

[Vanessa CW21]

Damn I can't believe I missed out on all the fun here!
Honestly I never cared to wonder what that jewel was doing there...
But now I've read the explanation of Ironstark, I tend to believe what he's saying! Sorry Nick...
Tomorrow I'll do some more research, and will let you know if I changed my mind!

Have a good night!
Vanessa

[wandyprawira]

This topic could be the topic of the year for TRF. I had no idea that this topic will involve plenty of arguments from all of the experts.

As a non expert in TRF, I am interested of the final verdict (the true purpose of the "dummy" jewel) and I'm sure everyone else is expecting the same as a fellow WIS. Therefore, please continue this thread with a calm, cool head. Please.

[Lol-x]

I telephoned Rolex Australia and asked if the jewel in issue was functional or non-functional. The reply was that the jewel was functional and that it prevented the datewheel from binding, and assisted in the free movement of it's rotation.
However, this was merely advice received from over the phone relayed from a watchmaker to the receptionist. I don't have the knowledge or experise to verify these matters, but I am very interested in technical discussion

[erasuretim]

Please Guys - Don't fall out over this. This is the only forum I visit that has actual watchmakers making regular posts. I enjoy and appreciate both of Nick's and Ironstarks valuable contribution to the community of Rolex fans.

But please, guys - just chill a bit

Regards

Tim

[JJ Irani]

Originally Posted by Lol-x

I telephoned Rolex Australia and asked if the jewel in issue was functional or non-functional. The reply was that the jewel was functional and that it prevented the datewheel from binding, and assisted in the free movement of it's rotation.
However, this was merely advice received from over the phone relayed from a watchmaker to the receptionist. I don't have the knowledge or experise to verify these matters, but I am very interested in technical discussion

Good input, Steve....thanks!!

I, for one, would find it extremely hard to believe and be convinced that Rolex would throw in 31 jewels in all their models (except for the Daytona which has 44) and even a single ONE of them would be NON-FUNCTIONAL!!

On another forum, this topic was discussed and an expert there (Dave Knoll) was pretty adamant that ALL the 31 jewels are FUNCTIONAL.

JJ

[bayhillrolex]

Originally Posted by erasuretim

Please Guys - Don't fall out over this. This is the only forum I visit that has actual watchmakers making regular posts. I enjoy and appreciate both of Nick's and Ironstarks valuable contribution to the community of Rolex fans.

But please, guys - just chill a bit

Regards

Tim

Don't forget we also now have Vanessa

[Ironstark]

Originally Posted by Nick Hacko

Those with better memory would remember that few months ago
we had discussion whether the 16613 crown is made out of solid 18K gold or not.
Despite all evidence provided, you still called the crown "monobloc" refusing to accept obvious.

This has nothing to do with accepting the obvious, it IS called and referred to as a Monobloc, plain and simple. I like to use the correct terms whenever possible. As was discussed at the time it would be impossible to produce a solid gold crown which functioned and lasted as long as necessary, ever tried using a spring made of 18 kt gold! Would`nt be much use. As much gold as possible is used in their construction as functionality allows.
http://rolexforums.com/showthread.php?t=16263&page=1

Originally Posted by Nick Hacko

Although I find your opinion(s) slightly biased I truly enjoy your
public responses for which I thank you.

I may be slightly biased in your opinion, but contary to your belief, I have the opportunity to work on a variety of other brands (in my own time) and I have trained in Switzerland with Omega, Rado, Longines and at ETA in Grenchen. Added to this the three years I spent at one of the original Horological institutes (set up by the Swiss watch industry back in the sixties) where we received instruction and worked on everything from tower clocks, to verge pocket watches, to electric and tuning fork watches, quartz and mechanical watches of all brands and types. I may have spent the last 15 years working for Rolex but I am well aware of their shortcommings. In fact my particular role within the company has afforded me an almost unique insight into the problems and faults which occur. Like all watch brands they have their own bugs and problems.
My view may not be as blinkered as you seem to think.
I have to say you don`t seem so unbiased either, or at least not so open to other`s opinions.

Originally Posted by Nick Hacko

Finally - and most importantly - the calendar wheel was not invented by Rolex. It has been around in it's current form for at least 600 years, "invented" by German clockmakers. Every single thinking maker since then is trying to solve the problem of friction between date wheel, date disc and it's support.

I am well aware it was not invented by Rolex (never thought it was) and as you say many manufacturers have tried to improve it`s operation and reduce friction. With the massive budget and R&D department at their headquaters, do you really think Rolex would install a jewel in any movement for no reason?

I have enjoyed the discussions etc.. on this forum until now.
I have no wish to become involved in any discussion or thread which becomes in any way unpleasant or confrontational.
Neither have I any wish to anger or upset any other member.
With that in mind it may be time to draw a line and end this discussion now.
Nick I have no wish to get into disaggreements with you or anyone else. This is a forum for sharing our experiences and observations with regard to our ownership and Rolex and their products.

[Jocke]

Hey, what have I started.

Come on guys, kiss and made up.

It´s only watches.

Have a great weekend my friends.

Jocke

[Tools]

Originally Posted by Jocke

Hey, what have I started.

Come on guys, kiss and made up.

It´s only watches.

Have a great weekend my friends.

Jocke

Hear...hear.....I'll second that motion

The world, and this forum, is made up of a diverse cross section of backgrounds, knowledge, and experience..

It's that interaction that makes life worth living, broadens our horizons, and expands our personal data base...

This entire discussion has enriched the entire forum family;.... we thrive on everybodies input....


Let's not screw it up

[S2000 Driver]