This Schatz 400 day clock came into my shop for repair. The customer told me that it had a broken mainspring. On disassembly, I found that the mainspring was broken in more than 15 pieces! (Normally, a mainspring has just one break). See photos below:
What caused the spring to break into multiple pieces?
The clock had been cleaned without being dismantled (there was debris in the gears from incomplete cleaning). The cleaning fluid could not be rinsed out of the mainspring. The fluid attacked the steel, causing stress cracks to form, followed by breakage.
Repair job 5176. Back plate number 1278, no date. Uses 0.004 inch suspension spring. When the mainspring broke, it bent the front second wheel pivot. I inserted a new pivot, and polished several other pivots.
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