2023-10-29

Last modified: 2023-10-29 19:45:38

• Stepper motor clock
• Tomorrow

Stepper motor clock

Progress has been disrupted somewhat this weekend, but should be back to normal tomorrow.

Latest is the clock is mostly assembled:

I fixed the worst tight spot in the train by reprinting the first wheel with a slightly smaller pinion, and I fixed the anti-reverse feature by making the slots in the Geneva-driven wheel bigger, and moving the steel pin slightly closer to its centre of rotation.

So now the clock works, including the anti-reverse feature.

The magnetic slip fitting to allow the setting of the hands seems to have tight spots, which makes setting the hands very difficult. Also there is some play in the minute hand because I accidentally cut the flat on the shaft too deep. So setting the time by moving the minute hand is inadvisable, instead it is better to rotate the gear that drives the minute hand, so maybe the plan is I should make some sort of fitting that allows turning that gear with a key. So much for not needing a key. Or maybe I just live with turning the gear by hand.

I've been running it for a little while this evening, and I've found that even when running in the correct direction, the pin sometimes gets caught in the little slot and the motor gets stalled. Need to work out what is going on there. I think it is if the Geneva-driven wheel happens to jump forwards a bit. Maybe I just forget the anti-reverse feature and use a ratchet instead... Also the overheating doesn't help.

Still to do:

• screw the motor in place
• stop the motor from stalling (how?)
• fit a heatsink
• build some sort of box at the back to house the wiring, with a clear plastic cover
• fit the dial feet
• make a dial
• make hands out of something stronger?
• take it apart, varnish the wood, reassemble
• demo video, blog

Tomorrow

• tidy the office
• proceed with stepper motor clock