Hi Folks, This is an observation and a question. I have an Anniversary = clock, perhaps also called a 500 day clock, as you only need to wind it = once a year, or so. I know very little about clocks, but have worked = on a few clock movements and escapements. I have some old clocks which = are 8 day movements. I wondered why the big difference in power = consumptions, and spring properties between the two types. The 8 day movements use a short pendulum which is maybe 1/2 second = natural period. The anniversary clock has a short spring, instead of a = pendulum, which is like a flat thread. This spring is fixed at the top = and has four masses, brass balls on the free end. One period of this = spring is about 8 seconds. The mass in motion, twist the thread like = spring, until the power of the spring stops the mass, and swings it in = the opposite direction. A different coiled mainspring then add a kick = to the mass and the cycle repeats. Always looking for different ways to obtain a 20 second period, I took a = band saw blade, cut it and suspended it from my shop ceiling. It now = hangs similar to the thread like movement spring of the anniversary = clock. At the bottom of the 72" band saw blade, I attached a 36" = yardstick. This now looks like an inverted "T". I added a mass to = both ends of the yardstick. I twisted the spring and released it. I = found it rotated back and forth and it period was about 8 seconds. I = keep adding equal mass to both end of the yardstick, and the period was = 24 seconds. The yardstick seems to always come to rest at the same point, as the = spring wants to untwist. My question: Has anyone tried this approach? If so, could anyone = direct me to more information about it on the internet? Thanks, TedHi Folks, This is an observation and a question. I have = an=20 Anniversary clock, perhaps also called a 500 day clock, as you only need = to wind=20 it once a year, or so. I know very little about clocks, but = have=20 worked on a few clock movements and escapements. I have some = old=20 clocks which are 8 day movements. I wondered why the big = difference=20 in power consumptions, and spring properties between the two types.
The 8 day movements use a short pendulum which is maybe 1/2=20 second natural period. The anniversary clock has a short = spring,=20 instead of a pendulum, which is like a flat thread. This = spring is=20 fixed at the top and has four masses, brass balls on the free end. = One=20 period of this spring is about 8 seconds. The mass in = motion,=20 twist the thread like spring, until the power of the spring stops the = mass, and=20 swings it in the opposite direction. A different=20 coiled mainspring then add a kick to the mass and the cycle = repeats.
Always looking for different ways to obtain a 20 second period, I = took a band=20 saw blade, cut it and suspended it from my shop ceiling. It now = hangs=20 similar to the thread like movement spring of the anniversary = clock. At=20 the bottom of the 72" band saw blade, I attached a 36" yardstick. = This now=20 looks like an inverted "T". I added a mass to both ends of = the=20 yardstick. I twisted the spring and released it. I = found it=20 rotated back and forth and it period was about 8 seconds. I keep = adding=20 equal mass to both end of the yardstick, and the period was 24 = seconds.
The yardstick seems to always come to rest at the same point, = as the=20 spring wants to untwist.
My question: Has anyone tried this approach? If so, = could anyone direct me to more information about it on the = internet?
Thanks, Ted