Plastic Clock

grabcad

This is a SolidWorks model of a functioning plastic clock that I bought from Australian Geographic in 2005. It does keep time, but runs a bit reluctantly due to friction in the bearings. Building it in SolidWorks allowed me to discover how a clock actually works: The drive train consists of a large number of gears that enable a few windings of the main spring to drive the hands for many revolutions (hours). The unwinding is controlled by the deadbeat escapement, which is timed by a pendulum. The funny looking escape wheel (white) is the last gear of the drive train. It can only turn (escape) when the anchor allows it to, which is every time the pendulum reaches its end positions. If you remove the anchor, the whole gear train will unwind in a few seconds; talk about time flying. The clock is fairly easy to model in SolidWorks, especially if you use a design table for the gear wheels, but it is hard to render well due to the transparent housing. This is why I prefer a screen view quality with outlines [Save as TIF/JPG from SW menu] which really makes the mechanism clear.