watches...

Here is a chart that i found...very informative. You can can see the differences depending on what "grade" your movement is...the main difference to note are the hairspring materials used, different shocks, and calibration standards. Note that the "standard" grade ETA 2892-A2 & 7750 movements doesn't exist. There is also no difference between top and chronometer grades, except for the few that are thrown away with respect to the stricter accuracy and testing in the chronometer grade.
eta_chart_sm.jpg~original


Difference between TOP and Chronometer?

Chronometer:
Average daily rate : -4/+6 s/d
Average variation in rates : 2 s/d
Greatest variation in rates : 5 s/d
Difference between horizontal and vertical rates : -6/+8 s/d
Greatest difference in rates : 10 s/d
variation in rate due to temperature : 0.6 s/d/C
Resumption : -/+5 s/d

Top:
Average daily rate : -/+ 5 s/d
Average variation in rates : not tested
Greatest variation in rates : not tested
Difference between horizontal and vertical rates : 15 s/d
Greatest difference in rates : 15 s/d
variation in rate due to temperature : not tested
Resumption : not tested
 
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Old post from "ulackfocus" to elaborate on above chart:

"There are also upgraded parts made with different alloys and materials in the higher grades. The Standard and Elaboré calibers use Etachoc shock protection, a nickel balance wheel with a Nivarox 2 alloy hairspring, a Nivaflex NO mainspring, a steel pallet lever and escape wheel, and polyruby pallet jewels. The Top and Chronometre calibers use Incabloc shock protection, a Glucydur balance wheel with an Anchron alloy hairspring, a Nivaflex NM mainspring, a Nivarox pallet lever and escape wheel, and ruby pallet jewels.

Explaining the advantage of a Glucydur balance over a nickel balance is simple: Glucydur (or beryllium bronze) resists deformation from temperature change or abuse much better than nickel so the balance wheel stays in balance and therefore keeps more consistent time.

As far as the hairspring materials, there are 5 Nivarox versions - 1 being the highest grade, 5 being the lowest. The difference lies in the consistency of the timekeeping performance due to small changes in the alloyed metals. Nivarox hairsprings consist of cobalt (42-48%), nickel (15-25%), chromium (16-22%), and small amounts of titanium and beryllium. Anachron is said to be a better performing alloy than any Nivarox incarnation which is why it's used on the Top and Chronometre grades. What metals Anachron consists of is another mystery. I've asked watchmakers here and in the real world and searched the internet for days without finding any information. ETA does also offer the option to upgrade from a Niravox 2 to a Niravox 1 hairspring with the nickel balance wheel on the lower two grades.

Explaining the variance between Nivaflex NO and Nivaflex NM mainsprings is more difficult - the alloy formulation changes are a trade secret so information is scarce even to watchmakers. I'm not sure if there is much of a change between the two since both Nivarox alloys are listed as 45% cobalt, 21% nickel, 18% chromium, 5% iron, 4% tungsten, 4% molybdenum, and 1% titanium. Do the math and that leaves 2% unaccounted for and who knows what elements fill that void. The difference in the NO and NM might only be tempering the end of the spring and bridle, but that would be an educated guess.

The difference between polyrubies and rubies is based in the manufacturing process. Polyrubies are made from powder that's heat pressed into shape. They're translucent, almost foggy. Rubies are cut from a man-made crystal that's formed in an electro-chemical process. They're completely transparent with better consistency. (click HERE and HERE for more on jewels and shock protection)

The change in shock protection from Etachoc to Incabloc is mostly about price. Incabloc costs more... but for a good reason. The Incabloc system is made entirely to in-house parameters instead of assembled from off the shelf pieces which is a real advantage on the quality control front. Even the jewels are custom made by Sietz (who have practically monopolized the jewel making industry) to Incabloc's specifications. It's also easier to service the Incabloc system. ETA does offer an upgrade to Incabloc on Standard and Elaboré calibers."
 
Blog regarding Miyota caliber 9xxx movements: http://www.ablogtowatch.com/japanes...eta-with-caliber-9000-series-watch-movements/

"Miyota lists the Calibre 9000 series has having between 10 - 30 seconds a day accuracy."

PDF file on Caliber 9015: http://www.citizen.co.jp/miyota_mvt/9015/pdf/spec_9015.pdf

The Miyota factory calibrations are about equal to the level of STANDARD 2824 calibration by ETA, which makes sense because caliber 9015 was designed as a cheaper alternative to ETA 2824 for mass production.
 
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Review of Seiko 7S26 automatic movement: The Seiko Diver's 200 Meter SKX779 Featuring the 7S26 Automatic Movement

Review of TAG 1887 and Breitling B01 movements: http://www.google.com/url?sa=t&rct=...AFI2BZuIXIZzPjg&bvm=bv.51495398,d.aWM&cad=rja

For those who don't know, Tag 1887 is based on a Seiko chronograph movement.

Do you by any chance happen to know what the defining differences are between the Seiko 7S36 and the 7S26?

*nevermind - the Google machine answers many things... Lol. Basically just Googling: "7S36 vs 7S26" gives lots of good results...
 
I was just given this watch...anyone know anything about its value? The face is a little scuffed but otherwise a very cool looking mechanical...
 

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...and the face. Sorry cant post more than one photo from my phone for some reason.
 

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Thanks! Free aint bad for a reasonable quality watch. I'll take it

I did not mean cheap btw...they are very good value. There is a huge following...kinda like Seiko5 fans. Now, you need a nice looking leather band for that skeleton watch...it is definitely a watch that you can really appreciate the mechanical aspect of it!
 
Bell and Ross

Any opinions on their square, ceramic models? Why are they so expensive?
 
Any opinions on their square, ceramic models? Why are they so expensive?

They make some fantastic watches but, yes, expensive. You can go to watchuseek.com to find out a lot about these and just about any other watch. Some very knowledgable people on there but it's an Internet forum so there are certainly bias' and fans.
 
They make some fantastic watches but, yes, expensive. You can go to watchuseek.com to find out a lot about these and just about any other watch. Some very knowledgable people on there but it's an Internet forum so there are certainly bias' and fans.

Thanks! I'll take a look at the site.
 

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