SP5B - 8 day mode
Hi Steve, firstly thank you for your amazing clock design! I've had fun building the SP5B in 8 day mode, but had some issues.
With a fully assembled test, sometimes it goes for 12 hours, sometimes for only 20 minutes, every time I start it again it seems to be random, but it's never been more than 12 hours. The pendulum swings around 2 to 3 degrees in either direction with a 2 Kg weight hinging directly without the pulley.
Sometimes I get the feel that it runs better after I've taken it all apart and put back together, or if I push the gears up or down on their arbours and start it again.
With the pendulum not connected to the escapement, it swings for around 6-7 minutes before stopping completely, I've tried 3 different types of bearings and tried IPA and white spirit to clean them that that's…

The escapement action in the latest video appears strong, even at the stopping point.
Pendulum amplitude fluctuations over long durations might indicate friction in some of the slower moving gears. That would include gears 5, 6, 7, 8, and 9. A good way to check this would be to remove gear 3 behind the escapement so gear 4 can spin freely. Check for increased resistance when rotating the winding drum. Possible friction sources could include oblong holes where gear 6 or 9 pass through the frame. Or a lack of end shake on the central arbor. Greasing the pinion teeth might help.
btw: What runtime option and drive weight are you using? It may be as simple as needing more weight. The 32 day option is a fun challenge, but there is an extremely low amount of energy given to the pendulum on each swing. The shorter runtime options are significantly more reliable.