Jump to content

Old mainspring without an inner loop


ifibrin

Recommended Posts

Surely not, who had worked on the watch must have discarded the broken piece when the repair was not made.

A broken mainspring is easy to diagnose from the outside because the watch winds effortlessly and forever. You would then start work as a repair, not just servicing. 

Link to comment
Share on other sites

1 hour ago, jdm said:

Surely not, who had worked on the watch must have discarded the broken piece when the repair was not made.

A broken mainspring is easy to diagnose from the outside because the watch winds effortlessly and forever. You would then start work as a repair, not just servicing. 

There is still a hole in the mainspring to engage the hook on the arbor, just that there is no loop!

Link to comment
Share on other sites

1 hour ago, ifibrin said:

There is still a hole in the mainspring to engage the hook on the arbor, just that there is no loop!

The mainspring broke at the point of maximum stress, typically where curving is tighter. If you inspect the edge you could be able to see signs of fracture instead of a manufacturing cut. 

  • Like 1
Link to comment
Share on other sites

I think we can concur what happened is what jdm has said the spring broke at the most stressed point, a previous repairer has removed the spring and re punched the hole but not bothered to reform the coil as it would require the  spring to be annealed and reformed, a cheap repair that would work untill the spring slipped the arbour and would not re engage. a new mainspring is required to complete the job.

  • Like 2
Link to comment
Share on other sites

29 minutes ago, watchweasol said:

 a previous repairer has removed the spring and re punched the hole but not bothered to reform the coil as it would require the  spring to be annealed and reformed, a cheap repair that would work untill the spring slipped the arbour and would not re engage.

I see what you mean. As soon the mainspring is coiled a little it keeps the hook in the hole. Maybe the recommendation at delivery was not to ever let the watch unwind completely 😏

  • Like 1
Link to comment
Share on other sites



×
×
  • Create New...