Why does my watch speed up?

[Goodgood]

My 7s26 progressively runs faster at all 6 resting positions after replacing the balance wheel. If I wear it, it runs normally, about +1~4 s/day. At a resting position, it runs within the tolerance, then it gradually speeds up until it hits around +96~110s/day.

I’ve demagnetized the watch, inspected the hairspring as best as I could with the limited equipments I have (20x loupe, maximum magnification). I have no idea what I’ve done wrong.

I’ve fitted the whole set of the balance wheel (a wheel, a staff, and a hairspring with a stud. Not the complete with the plate and everything.). The replacement parts are China-made probably, I got them on eBay. When it oscillates, it looks a bit more wobbly than the original one, and the hairspring was noticeably softer and easier to bend, but it showed acceptable ranges of amplitude (vertical +-220, horizontal +-270) so I didn’t think much about the quality of the replacement parts.

I did tinker with the replacement hairspring once because I twisted a bit when I was opening the tightly closed case. Touched it, looked at it from every angle. It looked fine to me. No visible foreign substances like oil and grease. The outer portion of the hairspring seems to be unharmed and aligns well with the regulator pin travel path(?). I’ll attach the low resolution photo of the hairspring.

Another thing that I’m thinking about is the regulator pins. I messed around with them a bit when I was trying to figure out what was wrong with the watch before replacing the balance wheel. But I can’t see them clearly with my 20x loupe.

((It’s a new watch, manufactured in 2021. It’s a long story but I replaced the balance wheel because I broke one of the pivots on the balance staff. I haven’t taken the watch apart fully, but I have disassembled then reassembled everything on the cover plate(?), meaning the rotor, the reduction wheels, the lever and the ratchet wheel. Haven’t touched the mainspring barrel or anything under the plate.))

I know this isn’t enough information but any ideas will be appreciated.

Thank you so much. I hope you have a wonderful day.

[JohnR725]

8 hours ago, Goodgood said:

I know this isn’t enough information but any ideas will be appreciated.

What are you using to time the watch? Are you using some sort of timing machine or app or something can we get a picture of that.

Then they hairspring is not attached the balance wheel how did that happen?

 

[Nucejoe]

14 hours ago, Goodgood said:

 If I wear it, it runs normally, about +1~4 s/day. At a resting position, it runs within the tolerance, then it gradually speeds up until it hits around +96~110s/day.

How long does it run  " within tolerance "   ? 

If its a  few  minutes, your oscilator has not yet stablized, so you would be looking at the rate in a transiant state , which is not credible. 

14 hours ago, Goodgood said:

 When it oscillates, it looks a bit more wobbly than the original one, 

so its out of poise.  220 to 270 amplitude doesn't gurantee the balance is poised. 

When on wrist , the rates in various positions can average out.    

Rgds

 

 

[Klassiker]

 Thanks for the comprehensive and detailed description of the problem and the events leading up to it. My guess is you are on the right track with your thoughts about the regulating pins. If the gap is wide and your hairspring is way off centre, i e. touching one of the pins at rest, then the rate will increase as amplitude falls off. A 20x loupe should be good enough to check this, but finding the right viewing angle and illumination can be awkward.