Hi all, I'm new to the forum so I think it'd be good to strat with a hi.

I just bought a Speedmaster racing as my first chronograph 2 weeks ago. Really live the watch but recently I noticed somthing or probably nothing on my watch:

1. The crown is turning all the time clockwise as rotor spins. So i took it to my AD who then asked someone very professional to explain this to me that everything in the a Valjoux based movement is connected and there is nothing to disenage the movement from the stem. It seems to be the case but the weird thing is I couldn't find anyone discussing this "porblem" on the whole internet since I can't be the only one who notices this. So...is this really not even worth mentioning or is there something wrong with my watch?

2. I "happened" to use the chronograph when date is half changed the other night. When I pushed the button, the date changed!!! I thought is was a coincidence at first then I tried it again on the day after and it happened again. I think the watch has a fast date change, which normally happens between 11:55 to 12 PM. My theory is that a push on the button gives whatever is turning the date a little "push" as well so my question is could this possibly bad for the movement and what is really going on in the movement? I know with some movements it is bad to change date via crown during 10 to 2 but I think Omega has fixed this problem on Calibre 3330 cuz the notice is no longer on the users manual. However using the chronograph doesn't seem to be the same.

Probably just 2 stupid rookie questions but the curiousity is killing me. Any help will be greatly appreciated. Thanks!!!

 

Can you post a picture of your watch to verify which one it is?

 

It is a speedmaster racing with ref number: 326.32.40.50.03.001

 

I would not adjust the date in that time period.

As for itjumping when you play with the crown near a date change I could see that happening.

As for the crown moving by itself as the watch ticks that seems a tad odd and I'd think something is not adjusted correctly and could be adding additional wear on the watch.

 

It would appear from the OP's post that he had been manipulating the chronograph pusher, not the crown...

Operations of those two functions shouldn't interfere with each other, I'd say.

 

Thanks for the reply. I wouldn't do that as well. Just found out that some of the manuals has the note while the one came with my watch doesn't.
The crown turns clockwise slightly only when you give the watch a little shake which spins the rotor and winds up the watch a little.

 

Thank you for the reply. It does seem weird to me. So I suspect it has something to do with the fast date change but I'm no sure and I couldn't find anything regarding this problem.

 

No, this is normal for this watch. I'll illustrate using a PAM 049 I'm working on right now, which is an ETA 7750 movement with different calendar parts, but it also has all the chronograph parts removed so it's easier to see what's going on without those cluttering up the movement.

Here is the watch in it's case:



The rotor only winds when it's turning clockwise (CW) as you view it here. When turning counter clockwise (CCW) it does not wind.

Now the movement is out of the case and I've removed the rotor, and added an arrow to show the direction of the rotor when winding:



Next layer removed, and you can see that with the rotor turning CW, the reversing wheel will turn CCW, and the reduction wheel will turn CW:



Removing the next layer the ratchet wheel driving wheel will turn CCW, the ratchet wheel CW as it winds the mainspring in the barrel, and the crown wheel will turn CCW. To the right of the crown wheel you can see some teeth coming up through the bridge - these are on the winding pinion. It's axis is 90 degrees from the crown wheel, and it is turned by the crown wheel teeth. The wolf teeth on the winding pinion turn the sliding pinion, and this in turn will make the stem and crown turn:



I took a quick video and added these photos to it to show the process and then show the crown turning as I spin the rotor with the plexi stick:

Note that when I spin the rotor CCW, the crown stops turning. There's nothing wrong with your watch in this regard.

The date jumper is a spring loaded part that rides on the teeth of the date indicating wheel. Once the date has started to change, the jumper is riding on top of one tooth, and if the watch is bumped or jostled, it can cause the date wheel to shift and the date to advance to the next day. Likely when you pressed the chronograph, it jostled thing enough to cause the date to flip since it was already close - once again nothing to be concerned about.

The 3330 does use a different date driving wheel that has a spring loaded finger on it and more like you would find in the 2824-2, or a 2892A2. Although I would not recommend changing the date via the corrector when the date change is in progress, there is far less chance of damage on this watch than on a typical 7750 that uses the rigid finger design. On those the finger can snap off if the safety mechanism is not working correctly, and one this one it's much less of a problem, but you still might bend something forcing the corrector.

Here is an older video I took showing the date change on an SW200, which is the Sellita clone of the ETA 2824-2:

I show how the date normally quick sets in position 2. Note that the date driving wheel has this spring loaded finger, and later in the video I position that finger as if the date change was still in progress, and the move the crown to position 2 and quick change the date. That simply compresses the finger on the date wheel, so it does no damage. This is that the 3330 looks like. Again I would not make a habit of this, but it doesn't present the same danger that the regular 7750 rigid fingers do.

Hope this helps.

Cheers, Al

 

OMG!!! Thank you sooooo much AI!!! I cannot find any word to express my appreciation! I've spent days literally trying to find answers to those 2 questions and failed. I am sure this is the only and best explanation on the whole internet. Extremely well explained and easy to follow. Now I've completely understood the mechenism that has been causing my confusion. Again thank you so much!!!

 

Glad you found it helpful. Just to clarify on some watches where there is a screw down crown, or even if the crown seal is tight on the case tube so the crown is a bit tough to turn, the wolf teeth between the winding and sliding pinions will slip so the crown won't turn. Just wanted to add that before someone posts asking what's wrong because their 7750 based watch doesn't have the crown spin during winding. With the example I have here I can hold onto the crown with my fingers and stop it from turning when the rotor is winding.

Cheers, Al

 

Haha...that's what my AD told me too when I asked him why this issue was never brought up for discussion. Apparently some people have their watches with screw down crowns while others just happen to ignore it. Thanks again for the extremely comprehensive explanation. I really learnt a lot today!

 

I also learned a lot on this thread. Nice to see threads like this one still happening.

 

Does this mean that the watches with screw down crown and 7750 tend to have more wear on those pinions because of this slipping?

Regards,
M

 

In theory yes, but practically they don't often need replacing for wear on these teeth.

Cheers, Al

 

Al - Though I don't own a Speedy Racing anymore, this was one of the most educational threads I've read on this forum. Thanks for putting in the time.

 

Dear Archer

I have read your technical answer about the date calendar mechanism and I found how great the information they are, which I did not know before.
However, I have one question about Omega 3330. Does the date mechanism of Omega 3330 changes slowly or instantaneous jump?

Very Best Regard

 

It's neither - this type of date change is called semi-instantaneous. A slow change will take several hours - some Omega quartz calibers are like this where the date moves at a constant rate, but slowly, through the date window.

The instantaneous systems flip immediately within a fraction of a second.

Semi-instantaneous systems start to move the numbers in the date window maybe 30 minutes or an hour before midnight, so you see maybe a part of the current and next date, and then at a point they flip to the next date quickly.

Cheers, Al

 

Extremely interesting and educational thread. Thanks Al for taking the time to explain this.

 

Glad you anticipated that, because I was wondering how it could turn this crown - I can barely turn it with my fingers.
Thanks for yet another educational post, Al.

 

That’s my thought too. The two functions should be independent of each other. And the date should not change until after midnight, not before.

The crown on my co-axial Speedmaster doesn’t move at all. I’ve never heard of one doing so without there being something wrong. I’d take it for warranty service.