I broke the extended pivot for a Tide hand

[GPrideaux]

I'm working on a Rip Curl "Classic Tide Watch" "17117 Stingray ATS" (according to the case back) where ATS stands for Automatic Tide System (as stated on the dial). When removing the hands to clean the movement the tide hand was difficult to move. It had very little clearance from the dial and my hand levers would not go under it. I eventually lifted it with a knife blade under it but instead of the hand coming off the pivot, the pivot snapped off at the wheel.

The movement is branded Technotime. The only things I've been able to see that might be calibre numbers are under the battery insulator: "7531 B" (or possibly ẞ) and "D02", but I haven't been able to find anything helpful by searching those. The tide complication sits above the calendar and motion works on its own thin plate that includes the hour wheel, an intermediate wheel and the tide wheel with the broken extended pivot.

At this point I'm not sure if I will be able to remove the broken stem from the hand and I have had no joy seeking a supplier for the broken part so here I am, hat in hand, asking for help! Was there something I should have done differently that might have prevented the breakage? And what can I do now to get it working again?

For reference, I measured the broken pivot at 0.22mm diameter. The tide wheel has 59 teeth and an external diameter of 5.13mm. I've also included a photo of the unbroken underside of the tide wheel.

[clockboy]

That is going to be a real challenge. The remaining part of the pivot will have to be drilled out and replaced with a new pivot. A watchmakers lathe and an accurate pillar drill will be the tool for removal of the remaining part and the lathe for making the pivot from pivot steel. If this task is achieved the the removal of the pivot from the hand IMO will be impossible due to the weakness of the hand material.. However finding a similar replacement hand should be easy ie look in a cousins Uk catalogue 

The other option is to identify the caliber of the movement and find a donor movement on eBay.

Edited July 19, 2024 by clockboy

[AndyGSi]

Can you post a photo of the movement and markings.

[GPrideaux]

I *might* be able to get a better photo of the markings, but I'd have to set up camera and tripod again and partially disassemble the movement. (The markings sit under the battery insulator.)

[GPrideaux]

Thanks for the reply, Clockboy. I have neither the tools nor the expertise to do that kind of repair. My only hope is to secure a replacement part/movement.

[AndyGSi]

Looking at yours and other TT movements they all seem to have a similar base.

What confuses me with your 7531 is that's a big date movement as below where I would have expected it to be a moon phase.

 

[GPrideaux]

I've been able to get some better images of the marks on the movement. There's a bit of chromatic aberration from my camera+macro+magnifying lens but it's definitely "7531 B" and "012". I still haven't been able to find any information on this movement. I'm assuming the 7531B is the caliber number but searches for Technotime 7531 only return different calibers (except https://www.sanihome.shop/archive/Uhrwerk-Technotime-tt-7531-B-Nos-Big-Date-Movement/e6gnrqoumttmvnp.html which Andy references above, and which looks like the movement at https://www.europastar.com/news/1001304232-technotime-extends-its-range-of-mechanical-and.html which is listed there as a TT 72310, not a 7531 B).

.

[AndyGSi]

With TT being such a small company it's possible that the 7531B is just a Part No. for the base plate which a lot of their movements are built around.