how to make a pendulum clock

[S Random]

does anyone know how, or a site which will tell me how to make a pendulum clock, basically need to know gear ratio, placement, and counter wieght amound for it to work

 

[Calin]

You start with a gear ratio - let's assume you have a "beat" of 1 second. You make a gear from 60 sec to 1 minute - this is to pull the seconds indicator one complete turn, and then one more 60:1 that will rotate the minute indicator. Another gear is 12:1 for the hours indicator.
You get the beat from a pendulum (a weight at the end of a stem. By varying the length of the stem you change the length of the beat.
Now the tricky part: you have at the end of the stem a V like thing, that will let one tooth of the first gear go when it is at one end of its oscillation, and another tooth go on the other end of the oscillation (in fact that end has to inside-pointing tips like this:
/_______
|
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The first gear is above it, the weight at the end of the stem
You now have a system that powers the first gear, and this will have to cover the losses of the oscillating mechanism.
Try to find a movie of the system, it will be much more clear from that.
Oh, and the hand watches don't uses the gravitational system but one with an counterweight and an spiral spring. They have faster beats (like 10/second, unlike the grav based clocks that have 1/second or something like that)

 

[Calin]

http://home.howstuffworks.com/clock.htm

 

[networkman]

Pendulum clocks