After a few false starts on finding the old school electronics that run this clock I found some that fit and work. Video attached is just the weighted pendulum with no gears but I’ll work on them this weekend. Excited to see this run.
I have made 3 of these clocks and all of them run slow. For example, I set the clock at 8:30. By 11:00 it was already showing 5 min slow. This is after I modified some of the gears. The modifications I made were to the gear that mounts to the motor (gear 6). I modified the hole to fit the shaft so it cannot slip at all.
I modified gear 5-15 and 5-30 to have a 22 mm round flat friction surface and cut a groove in one of the surfaces to fit an O-ring hoping to create more friction. I am using a silk filament for the gears and I noticed they slide easily when rubbed together so there was little friction between the gears. Hence this modification. I have been checking the clock regularly and they do not seem to be slipping now,
All the gears turn…
Figured it out. Had a bad solder joint on the Shield. LED's now flashing. Will test the clock now. Thank you for your help
On the MyMiniFactory website for the "Electric Pendulum Clock" SP7, there is a statement:
" There have been reports that the only driver circuit available as of June 2025 is not compatible with this design. Please hold off on purchasing these plans until the design can be updated and tested with the new driver."
Is this the current status?
Also, is this mechanism on Amazon the same? It sure looks to be. :)
In the past, the coiled battery connector was an indication of a useable electronic module. I am not sure if this is still true, but that does appear to be a good controller.
Is is running about 2 seconds slow per min. I know the gears for adjusting the time are NOT slipping because I glued them together for test purposes. I feel no binding when I tun the gear assembly by hand. I adjusted the pot on the driver to turn up the power to see if the motor was skipping. It is not. I have the jumper on the correct setting.
What am I missing here? Is there a way to "fine tune" the motor speed to correct this? Please help. Thank you
There are only three places for the gears to slip, and you have already ruled out most of them. The motor is not skipping, and the friction clutch is not slipping. The friction clutch is after the second hand, so the second hand would still be accurate if the friction clutch was slipping. The only other place that can physically slip is the stepper motor gear slipping on the motor shaft. Make sure to rule this out.
The next most likely causes are with the electronics. A 2 second per minute error probably has the correct jumper settings, so the first thing to check is the RTC. There will be a blinking LED on the Arduino Nano if the RTC is tracking properly.
The algorithm works in one second increments. It moves the motors slightly fast or slightly slow for one second, then checks if the RTC has sent a 1Hz pulse. If it detects the pulse, then the motor switches to fast speed mode. As soon as the RTC falls behind, then the motors switch to slow speed mode, giving the RTC more time to catch up. The LED blinks every time the mode changes. The difference between fast and slow modes is not noticeable and over a long period of time the motor will track the RTC exactly.
There is no way to fine tune the algorithm. It either tracks the RTC or it doesn't. The most likely cause of not tracking is a dead, missing, or mis-wired RTC chip if you built your own board.
Is there a blinking LED on the Arduino Nano?
The serial debug monitor would provide extra information but is a lot of steps if you purchased a pre-programmed board.
will be curious to see how well it keeps time. what old school electronics did you use?