New watch with Miyota 9039 -- A bit concerned with results/want to make sure nothing is wrong

[Conundrum1911]

Sorry if this is the wrong place to post, but given it seems to relate most to accuracy/timing I figured it fit here best -- I recently picked up a brand new Zelos Aurora with a Miyota 9039 and while wearing/testing the watch for the first week and a half I've noticed a few things and just want to make sure it is likely nothing (or if I should be asking for a replacement/repair):

When I got the watch I put it on my timegrapher and it looked great, around -2spd to +2spd, 277 amp, 0.0 beat error, settling mostly around 0spd.  That said, I've noticed when wearing it during the day and taking it off over night, sometimes it is -4spd over 24 hours, sometimes it is -20spd over 24 hours.  It seems once it is fully wound it works flawlessly for about 4-8 hours, and then it starts getting a bit random, and pretty terrible once it gets around 50% of the power reserve remaining.  Amplitude stays pretty good until the 50% mark as well, where it drops to about 230 and then 190 during the last 12 hours or so until the watch stops.

Also sort of odd, but if I wind it and leave the watch dial up on a table to run down and test it over the first day, any time I check the timegrapher it appears to be running no worse than -8spd, but somehow over that first 24 hours it can lose 15 seconds or so.

I've also noticed when hand winding the watch, after about 40-50 turns (probably 2/3 complete turns) there is a very slight clicking sound.  I assume that's the mainspring slipping given the watch is fully wound, but this is my first 9000 series Miyota and I've never noticed that on any Seiko watch or my Hamilton powermatic 80.

Anyhow, before wearing the watch a bit longer and potentially contacting the manufacturer, I figured I'd ask here what was everyone's thoughts and if this all seems normal, given I got good answers about another watch that had definite issues in the past.

Thanks

[mikepilk]

According to this https://calibercorner.com/miyota-caliber-9039/, the claimed accuracy is -10 to +30s/day. 

So yours seem well within spec. It also says about 40 winds to fully wind. So the clicking is the spring slipping. If you wear it for most of the day it should not need hand winding - this can cause wear on some auto movements, they are not always "robust" when being hand wound.

Sat dial up on a desk, it will be most accurate. Any movement i.e. wearing it, reduces accuracy. If you play tennis all day, it will not be very accurate. 

Also it the accuracy will change depending on how much the mainspring is wound.

 

Edited August 9, 2023 by mikepilk

[JohnR725]

58 minutes ago, Conundrum1911 said:

Miyota 9039

https://miyotamovement.com/product/9039/

always helps to have the technical specifications of whatever it is were talking about like the link above.

1 hour ago, Conundrum1911 said:

When I got the watch I put it on my timegrapher and it looked great, around -2spd to +2spd, 277 amp, 0.0 beat error, settling mostly around 0spd.  That said, I've noticed when wearing it during the day and taking it off over night, sometimes it is -4spd over 24 hours, sometimes it is -20spd over 24 hours.  It seems once it is fully wound it works flawlessly for about 4-8 hours, and then it starts getting a bit random, and pretty terrible once it gets around 50% of the power reserve remaining.  Amplitude stays pretty good until the 50% mark as well, where it drops to about 230 and then 190 during the last 12 hours or so until the watch stops.

it sounds like you are hoping to get a Rolex watch as that's the timing specifications you're looking for. This is not a Rolex watch it's timing specifications as outlined on the website above are ｰ10～＋30 sec/day. So until you go out of those specifications sounds that your watch is doing just fine.

then if you're concerned about the watch winding down at night and being bad for timekeeping purchase one of those auto winding devices. That will keep your watch always wound up when it's not on your wrist.

[Conundrum1911]

I did see the -10 to +30 "tested within 10 mins and 60 mins of full wind" which mine passes, I just find it odd that not too many hours later it dips to around -8 then -15 in the first 50% of the power reserve, then tanks to -20 or worse from that point onwards if the watch continues to wind down.  Ignoring the actual timegrapher results, the actual time tracked over 24h was about -15spd, but then Miyota only seems to rate them for the first 60 mins which is a bit pointless.

I guess I just find it odd given this is supposed to be a more "premium movement" than a NH35, but none of my NH35 based watches exhibit the same level/amount of increased gain or loss as they wind down (they do in maybe the last 20% before they die, but not before then).  But maybe this is par for the course with the 9000 series.

Edited August 9, 2023 by Conundrum1911

[mikepilk]

What counts is not what the timing machine shows, but how it performs on your wrist. It may show -20s dial-up on the timing machine, but hanging vertically on your arm and swinging about, it may be + several seconds, so that over time the performance is better than you expect.

See how it performs over 1 week. 

[Conundrum1911]

1 minute ago, mikepilk said:

What counts is not what the timing machine shows, but how it performs on your wrist. It may show -20s dial-up on the timing machine, but hanging vertically on your arm and swinging about, it may be + several seconds, so that over time the performance is better than you expect.

See how it performs over 1 week. 

Very true and that's what I am doing now, and recording the results every 12hr or so.  I was actually doing that before as well, and that's what caused me to look a bit deeper at this, as the watch was pretty consistently -2pd to -6spd, but then the next day was -15spd with it on my wrist all day.  I was pretty much active the same amount, but maybe the wind was a bit lower that day (but still surprised the loss could double from that).

[JohnR725]

21 minutes ago, Conundrum1911 said:

I did see the -10 to +30 "tested within 10 mins and 60 mins of full wind" which mine passes, I just find it odd that not too many hours later it dips to around -8 then -15 in the first 50% of the power reserve, then tanks to -20 or worse from that point onwards if the watch continues to wind down.  Ignoring the actual timegrapher results, the actual time tracked over 24h was about -15spd, but then Miyota only seems to rate them for the first 60 mins which is a bit pointless.

I think what you really need to do is purchase a watch with a chronometer certification. Chronometer certifications are based on how the watch does for timekeeping over time in various positions in various temperatures. It's not based on what it says on a timing machine.

timing specifications of watches are interesting and often misleading and confusing to the user possibly deliberately done that way. For instance Rolex usually specifies its timekeeping as an average over time not necessarily instantaneously. The case of Rolex and others timekeeping specifications based on the timing machine occurs at fully wound up and 24 hours later. Here watches only specified for fully wound up. Then the definition a fully wound up is 10 minutes up to 60 minutes. suggest giving you a range of this is a fully wound up watch and typically all the watch companies will give you a specification like this at least for what fully wound up is.

36 minutes ago, Conundrum1911 said:

I guess I just find it odd given this is supposed to be a more "premium movement" than a NH35, but none of my NH35 based watches exhibit the same level/amount of increased gain or loss as they wind down (they do in maybe the last 20% before they die, but not before then).  But maybe this is par for the course with the 9000 series.

what is the definition of premium? Because there is something in your specification that's different than and I'll get that in a moment let's look at the specifications for your watch timekeeping sucks at least by specifications but we also get this?

now this becomes interesting because and off to find some other specifications for you but to look at that watch within four different pendant positions and giving you a timing range. Not the kind arrange your expecting for a chronometer grade watch but still there looking at this watch in more than one position

50 minutes ago, Conundrum1911 said:

NH35

let's compare specifications

now farther into the manual you get something similar

now notice similarities fully wound up watch is done between 10 minutes and 60 minutes where did we see that before? Notice on the second image they say static accuracy versus on your wrist. Notice the only give three positions for timing versus up above with ask you look at it in more positions which technically does make that a more precise watch. Then they also give you timing machine specifications minimum of 20 seconds and stabilization time when you rotate the different positions.

then you'll notice the specifications above isochronism once again in a static position. This tells you 24 hours after its wound up that is what the timekeeping specification should be. This is your specification for basically amplitude variations. You will note that the watch you asked about it doesn't actually publish that it only has its specifications as a fully wound up watch. On the other hand it does specify more timing positions than this watch which as I said would make it more precise

oh and to understand the positional things I've attached a PDF. If you're hoping at your timing machine to give you a better prediction of what the watches doing you then need to time in a whole bunch of positions and do a whole bunch a math unless of course you buy a fancy timing machine that does that for you or some of the software timing machines will do this also. They will actually give you a number which gives you an approximation of what the watch should do on the rest. Versus one position on the timing machine that's not going to represent a watch on a wrist

 

X-D-DVH-Di-Im-N_EN witchy calculation of numbers timing.pdf

[mikepilk]

As @JohnR725 suggests, you might be expecting too much.  General COSC certified chronometers are between -4 and +6 seconds per day - your watch is not chronometer grade..

@JohnR725 - we are nearly posting at the same time 

 

[Conundrum1911]

Thanks, and I do get most of that, I guess I just find it odd that Seiko does list a 24h value and Miyota does not.  That is sort of what I was asking too, if Miyota says -10 to +30, are they also saying similar for the first 24h.  Most of my Seiko based watches are all in the  +5 to +15spd range but I haven't noticed that change much with amplitude (so they might not be accurate, but they are very consistent) whereas this Miyota 9039 seems a bit more random depending on wind even if amplitude stays close to the same.  Positionally though, the 9039 I have doesn't seem to change much or as much as my NH35s do.

And I get that I might be expecting too much, but also trying to figure out what I should expect here, and the above post does go into detail on that.  I am starting to think though for any future watch I buy for over $1000 I'm going to have to look for either COSC or METAS, given it'd bug me to see similar numbers come out of a watch I paid say $2000-5000 for.

In the end I guess I'll wear this one for a week/few weeks and keep tracking it, and if I notice anything completely off-base then maybe I'll reach out to the manufacturer (eg. if it sticks around -2spd to -15spd on wrist for 2 weeks then suddenly is something like -+60spd or more on wrist).  It also has a 1 year warranty so I guess if there was an actual issue with the movement it should completely show itself in that time frame, although I do rotate pieces every now an then in terms of which watch I wear for a day/week/month.

[JohnR725]

3 hours ago, Conundrum1911 said:

Hamilton powermatic 80

thinking about timing specifications since we were comparing let's look at that one

basically much tighter timing specifications would be my interpretation

I don't suppose you can see inside of your watch? Often times them transparent back seat and see your watch movement for instance I have a unknown Miyota movement the reason is unknown it doesn't actually say it just says that on the router 21 J made by the bering watch company. The reason I bring this up when I look at it it's all nice and shiny inside the finished the plate so they look nice and pretty but when I look down at the balance particular the regulator instead I'm not impressed. At least the Seiko is typically are using a etachron system and I think you get better timing specifications with that they Which is basically a standard regulating system.

 

 

[Conundrum1911]

40 minutes ago, JohnR725 said:

I don't suppose you can see inside of your watch? Often times them transparent back seat and see your watch movement

Not this one -- Both a solid caseback, plus a soft iron shield for added anti-mag.  From what I have seen online, the regulation setup on this one looks a lot like the Seiko in that it has levers for both beat error and rate vs any time of screw adjust like some ETAs do.  My Hamilton (with the Powermatic 80) is a crystal caseback though, as are a few of my NH powered watches.