On 9 Sep 2015, at 17:57, Jon Elson wrote: > On 09/09/2015 04:17 AM, andy pugh wrote: >> On 9 September 2015 at 02:36, Jon Elson <[email protected]> wrote: >>> I've wanted to make a clock that worked by having one ball >>> lifted up a track per minute, and the ball rolling down the >>> track flips levers to advance the clock and carry to the >>> next digit. Kind of merging horology with kinetic sculpture. >> You can buy those, but it would be interesting to make an attractive one. >> >> > I have a rough design already made up, uses wheels that are > advanced when the balls hit levers. Different length pins > on the wheels allow the levers to drop the ball to two > different tracks to perform the carry. > > I also had an idea to do BCD counters with mechanical > flip-flops and then the FFs would raise pins that would > select one of ten flags with the digits written on them. > The balls would have to be pretty heavy to activate all that > mass. >
That raises (!) the question of the energy balance within the clock/machine. The difficulty with ball clocks is that although the ball must do work as it "falls", you can't afford to take too much energy from it, because the more energy required to re-instate the ball the more difficult it is to power the clock with a spring. Electric rewind is fine, of course, but the real challenge is in a purely mechanical device. There have been several commercially available ball clocks in which the ball falls, but they often just leave the falling balls at the bottom of a chute or in a tray and they must be replaced manually. There is one nice design (the Ferris Wheel clock) with plans etc, but it uses electric rewind to lift the balls up a chute. I'm only aware of one type of working ball clock powered by a spring, and that is the Congreve which uses a ball as a regulating mechanism for fairly conventional clockwork. The ball rolls on a tilting table, and so falls a very small height (i.e. los es little potential energy). As the ball reaches the end of its tilted track, it touches a lever and that tilts the table the other way, as well as allowing the clock to advance. So the ball regulates the escapement. Difficult to make that kind of clock work at all reliably, but I have one here (just need to assemble the dials) and the Congreve certainly looks visually interesting, without being anywhere near the spectacular complexity of the one that triggered this thread. http://www.craftsmanshipmuseum.com/images/Wilding5.jpg Marcus > Jon > > ------------------------------------------------------------------------------ > Monitor Your Dynamic Infrastructure at Any Scale With Datadog! > Get real-time metrics from all of your servers, apps and tools > in one place. > SourceForge users - Click here to start your Free Trial of Datadog now! > http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Monitor Your Dynamic Infrastructure at Any Scale With Datadog! Get real-time metrics from all of your servers, apps and tools in one place. SourceForge users - Click here to start your Free Trial of Datadog now! http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
