This is a slightly unusual job, however these parts can get weak and break.
It's basically a very strong spring in an L shape, attached to the main driving cog of a clock.
It's the little piece at the top with two screws through it. Blue/black in colour. This is the bit that's left behind, there should be a little tail that fits in the groove directly below the second screw.
So firstly, getting a piece of metal. I could only find steel rod as I didn't have any suitable pieces in stock.
I ground down the side to a rough shape.
I've placed the broken piece on top. Taking shape!
Then, by what can only be described as a trade secret, I managed to imprint the holes needed exactly* where I wanted them...
*not quite exactly as the piece moved slightly. But for the purpose of this project, it'll be fine.
After much more grinding I formed the basic shape. Oh, that was after I drilled the holes. As you can see at the top.
There's a bit more to do. I'm very happy so far. It just needs a few more finishing touches. For example:
Shaping to size
A tricky counter sink
Hardening and tempering
All being well, in part two.