aaronm
2923
Variable-speed hands
I was thinking about the Japanese-style timekeeping over on the AHCI forum: http://ahci.watchprosite.com/show-forumpost/fi-16/pi-5569348/ti-824593/s-0/
He's implementing the variable-length hours in the obvious way, with a 24-hour face and hour indicator blocks that move around to synchronize with the seasonal hour length, since a day is always 24 hours. I was wondering how hard it would be to have a more normal 12 hour face, with fixed indexes and hands that moved at variable speed. So in the dead of winter the hands move really quickly from sunrise-to-sunset, and then much slower at night.
Such a watch would require 2 major complications, sunrise/sunset calculations AND the variable hand speed. I know we can do the first one, but I don't know about the variable speed. The naive way to do it, at least to my mind would be essentially to have a stack of horizontally-coupled chronograph trains, each with slightly different gearing and a cam set that engaged and disengaged them as needed, maybe only 12, an average speed for each month. You'd have to cheat some so that the 12 were in 6 pairs of matched speeds to get the day and night to align. There has to be a better way, but I can't figure out how to jam a CVT into a watch....
A
Variable-speed hands
I was thinking about the Japanese-style timekeeping over on the AHCI forum: He's implementing the variable-length hours in the obvious way, with a 24-hour face and hour indicator blocks that move around to synchronize with the seasonal hour length, since...
In love with your idea!
without having the faintest clue, except for the cam, of how to realize it technically. That could bring me into the habit of wearing two watches per day (or night) one on either wrist for the normal and one for traditional Japanese timekeeping. The monks...
A very interesting idea...
... in the 18th to early 19th century, there was a "Clock Man" in the Castle and he changed the placement of the weight (distance from the center) on the balance wheel in the clock so that the speed of the hand changed. So, there may be an answer in the "...
Still thinking.......
As you said, how to stick a CVT in a watch (and change the ratio twice a day) . Everything I have thought of up 'til now would just take too much power. So I keep thinking............................................... Makes an interesting way to keep the...
I was thinking last night..
and think that if we have an hour-only watch with a jumping hour, there's a way to do it. Build a stack of 3 cams, a usual jump-hour snail (rotating once per hour), a 12 hour wheel, jumps one position to increment the hour and a 1 year wheel which indicat...
Perhaps we could complicate this a bit more?
Can I restate the problem to see if I understand it? Your challenge is this - build a time keeping device where the 12 Hours (or 720 minutes or 8640 seconds) at night are longer or shorter than the 12 hours (etc) in the daytime. The time variation is dete...
Basically...
Though I was assuming this would be tied to a specific longitude and latitude, since it would have to know the time of sunrise and sunset to work at all. A