Not my usual area of interest but a clock with some sentimental value to a friend. It's a presentable "fake" oscillating balls under a clear plastic dome mantel clock with separate "pendulum" drive and clock motor pulse generator circuits fed from a common AA cell.
The oscillating balls bit works nicely as does the pulse generator (MB512 4MHz crystal controlled clock driver chip) but the clock motor now only responds to the pulses by stepping a few steps then just twitching. Holding it at strange angles may persuade it to run continuously (reminiscent of tired old tin alarm clocks!) so I suspect it's some sort of mechanical wear issue beyond my pay grade.
I was hoping to just drop in a standard cheap quartz movement but the case is too small for the widely offered 56mm square central hand drive units being only 59mm inside diameter. It's clearly not impossible to make a smaller, possibly non internal battery movement so I wonder if anyone here has any possible supplier knowledge?
The picture shows the existing rather nice looking motor unit in the clock head.
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