Hi,
I have a 500432 & 500901 BP, I am aware that both have the same movement if I am not wrong but I realised that for the 5009, it changes the date at exactly 12am whereas the 5004 changes at 12.05am.
I have observe that at about 11.15pm, the 5009 will starts moving the date wheel and the 5004 starts approximately at 11.30pm.
Does anyone know why is that so?
It's a mechanical watch hand assembled and the hands are fitted at the end of the movement manufacture, adjusting the hands to coincide with the date clicking over requires lifting the hands off and moving them by 5 minutes. But why bother? The next service and they may be out by more or less? You have nothing to worry about on either watch!
Questions about hand alignment appear here once in a while, they made me wonder. The pinion for the hands is perfectly round at the top, so the hands can be fitted in any position: some very accurate eyes and hands, and some tool if I am well informed, are required to do this right. Why not use a pinion that is slightly asymmetric, so that hands with a matching hole only fit in one way on the pinion: then it easily would be always right. Any reason why this doesn't happen this way?
Kind regards,
Paul
Because it probably would require very careful assembly of the watch in set alignment for a whole series of additional parts. The more parts that require assembly in set and finite alignment require time skill and patience to manufacture and likewise to service. The cost of both being added for owners account and to what end? Your life will not alter one jot with watches whose date does not click over at midnight precisely. It's a mechanical device and not a digital device.
I am not worry at all but just curious as to why is there a difference in the timing of the change in the date. All along I assumed that the hands are fitted at 12 o'clock sharp when they set the movement or when they test the date changing of the mechanism.
I have several IWC watches. Each has a different date change time. Generally they all change within 5 minutes of midnight.
Once I started collecting mechanical watches I decided not to obsess over these details, as long as the watch kept reasonably accurate time.
While I agree that my life will not alter one jot (?) because of watches that will or will not change date exactly at 00:00, and because of watches that run as accurate as a quartz watch or not, the question was about hand alignment in general. As most watches run within a few seconds a day, it is strange that not the same kind of accuracy is there when the position of hands is the issue: sometimes the alignment is a few minutes off, something that could easily be prevented with some technical measure. A watch of another brand lets the seconds hand jump to 0 and the minute hand to the marker position when the time is set: that is an example of a feature to have some perfect hand alignment. Such kind of a feature could also be envisioned for the moment of the change of the date, it could easily be seen as more practical than a watch that is fit for 2000 m water depth, or a watch that measusures some solar time. It could be as practical as a precision tourbillon.
Kind regards,
Paul
Whilst I do not know the answer to this, I will speculate that the movement in the 5004 and 5009 are not "exactly" the same. The date change process on a mechanical watch is not instantaneous as it is on quartz, there is a process that needs to happen, gears need to wind, levers need to move, springs compress / release, dials rotate etc and this all takes a certain amount of kinetic energy to happen and can be implemented in a couple of different ways so I would think it is possible that between 2 different watches the date change process may be different.
Some watches will have all the leg work done in the back end and will apear to change date almost exactly at midnight (store up some energy in a spring, release the energy quickly and rotate the wheel) where as others may have a more visual process (engage a gear that starts rotating the wheel some minutes before / after midnight and gradually rotate the wheel) - kind of like comparing a regular date mechanism with a retrograde one.
So is it possible that the 5004 and 5009 have a slightly different mechanism for the calendar wheel and this is why it looks like they change at different times?
Cheers,
Ben
I know it does not matter whether it changes at 00:00 or even at 00:15 but now it sounds to me that this is not an important detail for the design or assembly of an in house movement?
I would expect this to an important detailness requirement in any fine watches such as IWC.
I do have other brand watch which are in house movement but it does change on the dot 00:00.
It will be good if someone from IWC can shed more lights on how the watch is assemble or more information of the date change. Btw, both of the 5004/5009 that i have are brand new.
We have been talking about a date watch, now take the whole conversation to Day Date and perpetual models. The whole benefit of everything advancing in one fell swoop at 00:00 would be feasible but a nightmare to achieve, in the manufacure process, the assembly process and service details. The cost of manufacture and assembly would drive the purchase and servicing cost through the roof in my opinion. 5% gain in quality but maybe 50+% in retail cost. I have forwarded this thread to a proper expert from Richemont but the response may not be until the weekend.
One thing I do know is that no watch is made where between cogs and gears there is zero gap as the watch will be locked solid, there has to be the gap for allowing the wheels to turn and to engage and disengage for each cog. That is why it's not always easy to line the minute hand and second hand up when hacking the watch, I seem to stop the watch with the second hand at 60 secs but have to advance the minute hand so it looks as if it's 20 secs into the appropriate minute as it takes up the slack and engages all cogs.
My JLC Perpetual (IWC Calendar plate, btw) used to finish changing day date around 2330h. It went in for service for a problem with the center seconds hand and now the day date changes practically at midnight. So as someone mentioned earlier, it can change as it gets serviced.
Hi BIW,
If it had gone to JLC for its service, your JLC perpetual would finish changing the date at 0300h, synching with the end of your red-zone indicator.
JLC decided on 3am so those awake in the hours leading up to midnight can, at a glance, be certain of the date, rather than having to work out whether the hands are about to jump, are in the process of moving or have finished jumping.
Less people are awake between 12 and 3.
Leo
Hi guys,
As we have discussed in a previous thread, IWC employ 3 different methods for date changing in their simple calendar watches.
1)Instantaneous, where power is slowly gathered in a cam then released suddenly, knocking the date indicator forward one day. This is used in the calibre 80110.
2)Semi-instantaneous, where the power is gathered in a spring mounted on a wheel(pictured) and released when the power in the spring overcomes the power of the spring-loaded date click. This is used in the 5000 range.
3)Standard, where a finger on a wheel slowly pushes the date to the next day. This is used in the 792xx chronographs.
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](s1152.photobucket.com/user/leosweeney/media/DateInterlockingWheelSprung_zpsff66722f.jpg.html)
All watches, from all brands, have an accepted tolerance between the hands and the date change.
This tolerance can be very tight for methods 1 and 3. 3 or 4 minutes either side of midnight being the norm for method 1 and 4 or 5 for method 3.
The tolerance for method 2, the wheel imaged, is larger. Up to 7 minutes either side of midnight. This is because the power required to arm the long circular spring can vary from the day the hands were fitted.
The method employed in a particular movement depends on the available torque and what other functions are also drawing power from the barrel.
Method 2 has the least influence on the accuracy of the watch as the power is built up more evenly over a longer period of time.
There can be as many as 8 wheels between the movement(hour wheel) and the date indicator disk. By necessity, there must be a little play between the teeth of each and this adds up quickly. You can see this in your own watch by observing the difference between the time the date changes 'naturally' and the time the date changes when you turn the hands with the crown.
To get back on topic and summarise, the 5000 range has an acceptable variation in time of date change between watches as a consequence of IWC's strive for timekeeping accuracy.
Leo
@Leo,
Thanks for this very clear explanation. It goes a long way towards explaining the characteristics of my various watches and their movements.
Many thanks to one of the genuine experts, Leo, who knows the answer to this and other questions that we manage to conjure up.
Thanks to all who have answered to my query.
