Extending the runtime
  • So - I've got a pile of mecanno kicking about and since my Sept. has been running very well with some new, thinner waxed string, I decided to have a go at increasing the 'run-time' of the clock. I tool the weight off the string and attached the weight to a pulley and tied tied the end of the string to the lower brass tube - the weight now hangs in approx. the correct place, but as now takes twice as long to drop to the floor.

    The downside, of course, is that now it only exerts half the force it previously did on the clock mechanism. This turned out, in generally, not to be a problem - I must have made a better job of polishing, aligning and getting this clock put together than I thought. I ran fine - and, of course, with the less force going through the clockwork - more quietly.

    Till six PM when it stopped. And six AM, and then again six PM.

    Now, not being particularly mechnically minded, I suspect that this means that (well, -has- to mean) the problem is in the gearing on the hour hand - though quite why this enough to stop the clock, yet doesn't if I adjust the time by turning the hands backwards, I'm not sure - so I'm running it now without an hour hand to see if it stops overnight. Hopefully not - but I'm going to do a bit more work on the gearing of the hour hand - where the smaller cogs are glued to the larger, I think there is some glue which the gears are meshing on.

    Of course, as I've halved the driving force, I could probably get around this by making the weight a bit heavier so - 1.2kg, perhaps - but while the clock could take it, I'm more worried about my wall fixings!

    Also need to do something about the winding string, which of course is now twice has along as it needs to be - will have to consider doubling that up to - I'm thinking about attaching the other end of the winding string to the main arbour with a loose knot - it only needs to support the weight of half the winding handle, after all, and that's the nearest point directly above or below that side of the barrel.
    Any thoughts?
  • Well, it's stopped again - even without the hours mechanism. This time though, I was able to determine the cause - the string holding the weight was fouling the 'clicks' on the barrel. I need to do someting about that - either try and add a spacer to keep the string away from the clicks, or, perhaps, make some sort of washer (maybe from clear plastic) to prevent this. Otherwise 500g , generally, is enough power to run the clock.