NH35A acting up

[rodia77]

Yep, CFR's favourite. (BTW, is C taking a break from us? Haven't seen him posting for a good while now).

Until recently, the NH35A in my Stoic was running like a champ: less than +5spd. But in the last few weeks/months, when wearing it, I noticed it slowed down rather dramatically, and I have a vague memory of it stopping at some point during the night.

My measurements from when I was winding it up manually every day:



And from yesterday, when I deliberately didn't wind it, just gave it a few shakes for starters and relied on my natural movements (or lack thereof ) only:



Even with the winding, you can see that it switched from a very nice plus to a slight minus (just like my Hammy a year ago, coincidentally).

When I turn the watch around in my hand, the rotor doesn't seem to be blocked and is pivoting normally. I suspect something is wrong either with the winding mechanism or the mainspring (could something have loosened?). A simple extreme case of isochronism is rather unlikely given that the behaviour occurred quite suddenly.

[gnuyork]

Whatever movement is in my new SKX SUCKS. I haven't timed it, but even after a few days I am minutes slow. And I think I have noticed it stopping on occasion, even when wearing it all day. I may consider swapping the movemnet in this one eventually.

And yeah, Where is C? Did I miss a message that he is on vacation? I was away for a while while I was in NY visiting my parent and I miss stuff.

[tribe125]

I’ve missed CFR too. I don’t think he mentioned a break or a holiday.

[gnuyork]

I’ve missed CFR too. I don’t think he mentioned a break or a holiday.

I hope he's OK.

[Henry Krinkle]

I think C's quietly slipped away for a break before. In these times I guess we hope that's all it is.

[chuckmiller]

For a man with over 12,000 posts he is being surprisingly quiet.

[Sedi]

Most of my Seiko movements run fine but they run like crap as long as they are not fully wound, which can take up to two days on the wrist with my activity profile (typing on the laptop and sitting on the couch mostly). Still strange that yours changed its behaviour so suddenly. And it's certainly not the "usual" messed up balance spring which would make it run very fast.
I'd have a watchmaker look at it.
BTW -- I do have a J.Springs with that movement on which somebody did turn the lever all the way to "+" since the same thing seemed to have occurred -- the watch getting slower and slower over time. At leat that seems to be the most obvious explanation.

[rodia77]

After wearing it for a day, with not a lot of physical activity involved:

[skywatch]

Have you tried adjusting it? Another thought (I usually think it's the least likely option) might be magnetic fields. If you have a demagnetizer you could try that. I tended to think that magnetized movements tend to run faster not slower, but that's just what people say on forums.

[rodia77]

I demagged it before taking that first measurement a couple of weeks ago.

I think the connection between winding and rate is quite obvious, I expect it to slow down over night and speed up over tomorrow, and then I'll give it full winds for the next night and next day to see how it changes things.