This mechanical clock demonstrates that 3d-printing is not just for decoration. It's possible to create intelligent, living things. The clock has an anchor escapement, and a balance-wheel with a spiral spring. The clock shows Seconds, Minutes, and Hours. The winding has a nested planetary gear, which allows that the clock continues to run, while winding up. Everything is 3d-printed (even the spiral spring), except e few small screws, some metal pins, the cord, and the lead for the weight. This video shows the clock and the building process (actually with a simpler ratchet-winding): http://youtu.be/HgZBPYJ2Y-w Designed with Blender. PLA printed with Rapman 3.2.Some parts require a loose clearance (hollow shaft for hours and minutes), other parts require a press fit (hands). The 3d-files are optimised for older printers with more inaccuracy in xy, or a badly guided z axis. I.e. when printed with a newer generation printer, parts are most likely too loose. In order to compensate this, the material flow could be increased (over-extrusion). In Simplify3d there is another useful parameter: "process settings / advanced / other / horizontal size compensation". Pins:Screws:There are STL-versions with 2 x 2 combinations for the winding: a) Simple Ratchet v1: 4.22 revolutions per hour (weight moves 26.5cm/h) b) Simple Ratchet v2: 2.25 revolutions per hour (weight moves 14.1cm/h) c) Planetary Drum v1: 3.01 revolutions per hour (weight moves 18.9cm/h) d) Planetary Drum v2: 1.61 revolutions per hour (weight moves 10.1cm/h)My clock works well with version c) and 1.2kg weight. For version d) I'd probably need a weight of 2.3kg. The actual needed weight depends a lot on the friction of the whole system.