Grand Seiko beat error

[Kkramme]

I love my Grand Seiko Tentagraph bought new last year but was originally concerned about a beat error of 2.5.
 

Just in case— under warranty— I sent it in for repair back to Japan. Little did I know that it would take 6 months to get it back! 

And now it still has a beat error of 2.5 (but average rate (s/d) of -2 and amplitude of 233.

Should I be concerned? 

[AndyGSi]

Depending on what timegrapher you're using the lift angle will have an effect on the amplitude.

[Kkramme]

4 hours ago, Kkramme said:

I love my Grand Seiko Tentagraph bought new last year but was originally concerned about a beat error of 2.5.
 

Just in case— under warranty— I sent it in for repair back to Japan. Little did I know that it would take 6 months to get it back! 

And now it still has a beat error of 2.5 (but average rate (s/d) of -2 and amplitude of 233.

Should I be concerned? 

Timegraphers can be less than ideal for measuring the beat error of your dual impulse escapement (just like they can have problems with Omega's coaxial escapements). The impulse delivery in your 9SA5-based movement is by definition asymmetrical.It's unlikely the watch had to go back in the first place; I'd trust Grand Seiko on this unless your watch is outside of accuracy norms. [from a knowledgeable person]

[Nucejoe]

 No expert here, yet a dual impulse deliverer and beating 36000 per hour,  9S..   series  can afford low amplitude of near 220degrees for  its inhernt magical  benefit. 

Sounds invalid ?      what do I know,   shoot me. 

Rgds

 

 

 

Edited July 20, 2024 by Nucejoe

[JohnR725]

9 hours ago, Kkramme said:

Grand Seiko Tentagraph

In a watch repair discussion group you don't even give us a picture of the watch? 

Fortunately grand Seiko has a website and I can get descriptions and pictures there

https://www.grand-seiko.com/us-en/special/9s25th/chapter7/index

https://www.grand-seiko.com/ca-en/collections/movement/mechanical/9sc5

9 hours ago, Kkramme said:

Just in case— under warranty— I sent it in for repair back to Japan. Little did I know that it would take 6 months to get it back! 

One of the problems today and watch repair is there's a lack of people doing watch repair. So six months while it may seem like a long time to get it back is actually quite quick as you might be waiting much longer for other places. 

9 hours ago, Kkramme said:

And now it still has a beat error of 2.5 (but average rate (s/d) of -2 and amplitude of 233.

Should I be concerned?

One of the problems with unusual escapement's are the timing machine has to be designed to work with them. For example Swiss witschi has other settings for other types of escapement's. Because this isn't your conventional lever escapement the rules do not apply and the timing machines do not work with them.

Then even if you had a timing machine which you don't because there's probably a custom machine it would still be basically worthless. Typically for watches like this chronometer grade watches they are timed over a span of time compared to a very precise standard. The timing machine points your direction but chronometer specifications specify timekeeping over time. So the instantaneous if your timing machine works which it doesn't can have errors because that's not how these watches are timed.

Then I did find some timing specifications later I found more timing specifications if you poke around the blanks I have up above you get all kinds of specifications. Like for instance where's the amplitude or the beat? Obviously grand Seiko does not intend their watches to be sold by anyone on this group because the most important thing on this group is your amplitude and they would even give a specification for that. That's because typically the normal customer would care less about those things typically all they would care about is timekeeping. I suppose based on the specs below your off by one second that is providing your time source is more accurate than the grand Seiko and as I said you would have to do this over a span of time.

So basically your watches running fine. Grand Seiko really needs to have a place to send the customer to to reassure them that their watches working perfectly and there's nothing wrong with their watch.

 

[Nucejoe]

 GS TENTAGRAPH  needs no introduction.

Selfwinder version,  houses Cal 9SC5,  which I think has so far  remained  unrivaled  among GS beaters. Its timekeeping beaten only by GS spring drive, which I have one ( spring drive ) and can vouch for. 

@Kkramme   as John described, your TG  is unlikely to have recognised  the escapement in your watch. 

Rgds

 

 

 

 

Edited July 20, 2024 by Nucejoe
spelling

[Knebo]

7 hours ago, Nucejoe said:

 

@Kkramme   as John described, your TG  is unlikely to have recognised  the escapement in your watch.

+1.

What I'm curious about, is a correct reading of the amplitude. 

This is a movement with 36'000 bpm and I wonder if they have the same desired range of amplitude. I'll refrain from giving numbers, but you all know what I mean. Or if someone has experience with El Primero movements. 

I can offer one anecdote. I saw a Chopard Alpine Eagle Cadence. That movement runs at a ridiculous 57'600 bpm (8 Hz). According to an article I read, it should run at around 200° amplitude. The one I saw was running at about 135° only (I took a super slow motion video of the balance), but it wasn't fully wound. 

 

[Nucejoe]

Hi knebo.

This stuff is news to me.

 With high frequencies though, amplitude can be reduced to 220 degrees, ideal for isochronismic state for the oscillator, should add simple single impulse Swiss lever escapement. 

Possibly this 135 degrees amplitude is no longer invalid by standards  of new improved horotech.

Make me feel old.

Rgds