From: utzoo!decvax!ucbvax!CAD:tektronix!tekmdp!bronze!randals Newsgroups: net.physics Title: Re: perpetual motion puzzle? Article-I.D.: bronze.392 Posted: Mon Jan 17 10:24:44 1983 Received: Wed Jan 19 08:15:26 1983 ~~~~~~~ original question ~~~~~~~ Has anyone out there seen some clocks on which the hands are attached to some CLEAR plastic, and there are no visible parts behind them? All you see is the clock hands and a piece of transparent plastic. They are very expensive. Anyone know how they might work? Rick ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The mechanism is rather simple, once you figure it out (and it took me a LONG time!) The hands are printed on clear round disks that are the size of the entire clock face. Each disk sits on a couple of small rollers in the base of the clock, and is supported so that the disk can turn. The small rollers in the base are simply turning at the proper rate to make disks (and hence the hands) appear to "move" at the right speed. Clever. Not afraid to have a good time with my name, Randal L. Schwartz Tektronix Microcomputer Development Products Beaverton, Oregon, USA UUCP: ...!{ucbvax or decvax}!teklabs!tekmdp!randals (ignore return address) CSNET: tekmdp!randals @ tektronix ARPA: tekmdp!randals.tektronix @ rand-relay