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Stopped after half an hour because a gear axis slipped out of sleeve and then wouldn’t start up again properly. Turned out it’s wound down too much with all this tinkering so had to rewind. Ticking again. Once I get it going for a full spring winding cycle I’ll work on accuracy.
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What’s really clever is that the contact forces generated by a 1s pendulum would be too weak to directly compete with a powerful mainspring. But the ~ 2 orders of magnitude gear reduction creates enough mechanical advantage that the 1s pendulum can regulate it
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Ie the gear down to generate minutes/hours to tell time is also what creates the leverage to control the dynamics. The range this trick works goes from Big Ben to desktop size. And then you switch to a balance wheel oscillator instead of gravity, to go down to wristwatch size.
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Today, for the first time, it’s been going continuously for over an hour without stopping, after some fairly brutal microsurgery on the gear train. Sometimes you gotta brute force this shit a bit
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2 hours and counting. Holy crap there’s a small chance this will run a full 24h. Afaict I’ve bullied all the frictions into submission. Fingers crossed 🤞
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Since it's a mechanical clock, 12 hours is the full cycle test. If it makes it past 12, there's no sticky bits anywhere in the gear train. Interesting... just hit me that since such clocks are typically meant to be wound every day, each windup is n=2 full cycles.
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If it makes it, I'll do a final light tightening of all wobbly bits, maybe paint some fluorescent numbers on the dials and hands, and put it up on a shelf.
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I'm going to have to resist the temptation to fight this endlessly. I mean this is laser-cut wood, push-fit assembled. Still, getting it to run a full spring-wind-down seems like not too much to ask. I don't need perfection. Just outlast the unwind.
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Rube Goldberg Chindogu idea... attach an arduino meta-control loop that notices if it stops via optical sensor interrupted by the pendulum, and gives the rocker a li'l kick if it does
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Anyone who gets this kit built and ticking smoothly on first attempt is some sort of mechanical genius. I’ve gone: 10s, 30s, 55s, 5 minutes, 25 minutes, 55 minutes, 4.5 hours, and now back to 20-30 min range. I suspect it’s the spring force wind-down.
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Yup. Rewound to full tightness and it’s going steadily again. I may be down in the noise zone of friction. It’s not a specific sticking point. To test this, I’d have to note all gear positions at each stall. Should be uniform random?
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I’ll measure this, but after first stall at 4:30, with each gentle impulse on rocker it went for a shorter interval each time. By the time it was ~1 minute, strength of initial impulse was determining the duration so pendulum was driving, not spring.
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I’m sciencing the shit out of this problem that Huygens cracked in 1658 😎 Bringing up the rear of the scientific revolution like a boss.
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Looks like the spring is maybe not actually designed for 24h 😬 Well let’s see how long I can get it to run, and how much energy is left in the spring when it runs out. I’m guessing 5-6h with my slightly shoddy assembly, maybe 10-12 if perfectly assembled.
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Replying to @vgr
Not sure if it’s the same kit, but the Amazon listing says it’s not meant to run for an extended duration. - This is a model clock kits, not a real clock. - The clock will run for a few hours once it is fully wound.
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New record: 4:59....😬😬😬😬 Damn thing couldn’t scrape through to 5 huh I’m gonna call this done. Looks like this is actually close to the spring limit. Probably only has another hour of juice left tops, if I keep rejogging the rocker
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