The Breitling Watch Source Forums

Hi all,
I’ve notice that something on Navitimer or Montbrillant watches: they have measuring scales on frame and dial, however, when you turn the frame to match the scales with the ones on dial, you cannot match partially, a few of scales cannot be matched 100%. Would appreciate someone can tell me why it is? What’s the purpose? I believe it’s not a technical issue from Breitling side.

As far as I know the Navitimer sliderule is aligned identically to other circular sliderules. The B-1 is different because it is geared, but I think that's just how circular sliderules are.

Here's a pic of my Navi (should have cleaned the crystal first I guess). Which scales don't align?

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Breitling Navitimer: Black Dial
OMEGA Speedmaster Professional
Steinhart Nav.B-Chrono II
Elgin-Hamilton 37500 (Aircraft Clock)

OP, do you have a picture of what you mean as the slide rules on my watches seem to match up....

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You can see in mjfur's photo - when the 60s are lined up the 10s are fractionally off.

Gotcha, thanks, guess I never even really notice that before.

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on a side note: the original Breitling sliderule launched with the Chronomat in 1942 did not align at all, it was a true logarythmic circular sliderule.

Hi Zilong,

This misalignment is not uncommon with Breitling and many other makers’ offers on SRW. If you look at Art Simon's Slide Rule Watch website, he has an explanation of this. http://sliderulewatches.yvod.com/

The two Scales C, D are single decade Logarithmic scales and are matched as a pair before installation. That is, there is a tolerance that is acceptable, and outside this, they are not acceptable. It would appear that watch makers in general apply their own rules to what the tolerance should be. Sinn, Anonimo, Tag Heuer and Breitling would appear to keep fairly close tolerances, where as others are less so.

There is no clear way of describing the inaccuracy that I know of and it is sometimes hard to express. Each Graduation line on the scales can be described as a ‘thickness’ and the amount of inaccuracy can be determined as a proportion of that thickness. Art uses the term ‘Tick’ to describe it, which seems reasonable as a nomenclature. So if the graduations at 10 or 60 are 3 time the graduation thickness, then its 3 ‘ticks’ off being accurate.

I once had a watch direct from the maker that’s C,D scales were 7 ticks off at 10, when 60 was aligned. This made accurate calculations almost impossible. To their credit, they paid for the return of the watch and a complete replacement, quickly and with profuse apologies. I won’t name the here, but it wasn’t Breitling………….

Some watch designs places the two scales with a separation. Art and I believe this is the last refuge of the scale rule scoundrel, as it’s easy to become a little lax on the tolerance. Inverted scales, such as those found on early Chronomats can be measured too, but it takes a real calculation to do this. You can’t just line up the scales - as one is inverted and makes no sense like it does on a Navitimer.

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Jim

"You have Control".

Thanks all for your responses!

I should remove Navitimer from this post, because since I posted it I checked with some friends who have Navitimer they are all pretty much alignment. Most friends with Montbrillants are not.

To P51, thank you so much! That was something really educates me a lot!

Herewith a picture of my Montbrillant. I matched 60s, it's very noticeable for 45s,40s, 35s and 30s
Please your comment.

That's not very good. Best way to test the accuracy is to do some simple tests. Try some multiplications & division sums. It will become obvious when you see the amount of error that occurs. I think at worst this is about 1.5 ticks off. Not great really. Not much that can be done, as it relies on a matched pair of scales. The likelihood of getting them & the cost of the change over would very expensive. If the watch is under warrantee & the consumer laws in your country allow, you may be able to get it fixed through your local AD, providing you bought there. I see this on many occasion & its disheartening.

My most accurate watch is a Sinn 903. Absolutely dead accurate. If only all watches were like that.

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Jim

"You have Control".

Hi Jim,
I tried some calculations by using the scales, not great results.
It's a new watch I ordered from AD. I kind of enjoy it now. Wonder if I could told AD this problem and ask them to get Breitling to fix it when the watch needs a service, say in 2 years time?

Hi Zilong,

You will need to check the warrantee but I would be returning it now. If its brand new & it cannot do what it says it can do then you should have the right to exchange it for one that does. If you lived in Australia then this right is protected by law regardless of what the warantee says. Not sure about your location. If it really annoys you, then take it back & tell them this watch is faulty & outside specification. They may elect to repair it but they may also swap it out instead. They may try & tell you it's normal. I would not be agreeing to anything less than some action on a fix.

It serves as a reminder to breitling that when you make a promise, you have to stand by it.

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Jim

"You have Control".

Jim, thanks!
Finally, I got an ansewr from Beritling South Africa where I live. They said their quality control department confirmed that the slide rule is out of tolerance, they will repair it in their workshop.
Rising another concern, i suppose they try to repair it with local workshop, is this repairment very simple? align the bezel? or anything? I don't want them mess around with my watch's caliber.

They will simply replace the outer sliderule insert.