A somewhat extended fettle. We have a pendulum mantle clock with chime that, some time ago, gave up chiming properly. I decided (that time ago) that it wasn't worth a proper repair by someone who knows what they were doing (it was something we had picked up in a second hand shop for about £75) so, I would have a go. Googling about, it looks something like this
I was ever so pleased that I managed to work out the issue (a bent component) and restore the chime as it should be. I also had some other mechanical repairs to deal with for the clock mounting. Only, when I went to proudly return it to its place, it didn't work (it had worked before)
Fast forward more than a year and, after looking and thinking, thinking and looking, I considered it might well simply be the orientation of the clock in the body, as pendulum clocks are sensitive to small variations. So, by dint of padding up one side and then the other with sheets of card, I established that this was the case, and the amount and direction of error. A small pencil mark to give me the register, a less than one degree turn of the clock in the body and it has now been running for over 24 hours. Happy dance.
Just for the hell of it, here's the real thing
Both were marriage presents, so that was clearly a "thing", the stock one from 1915, mine from 1897.