Update: checkout my own alternative design: "Customizable Planetary Gearset (Cycloidical)" http://www.thingiverse.com/thing:488993 This is a slight modification to emmets gear bearing that makes it post assemblable. Advantages: 1) Zero clearance possible 2) Multicolor with single nozzle printer possible 3) Seperate prints -> no travell moves -> better surface quality edit: Don't use zero clearance (the *stl's have), increase the tol parameter to at least 0.3mm so the parts can be put together.edit: Don't use zero clearance (the *stl's have) - it turned out assembly becomes almost impossible and it may not turn at all. 1) Print all parts separately (I dissuade from using the print-plate) and the sun gear split in two. 2) Put the planets and half of the sun into the ring. 3) Put the other half of the sun in 4) Screw it together with a threaded rod and two nuts. For a demo piece my sheet pin can be used to hold it together: http://www.thingiverse.com/thing:42665 Here with fitting parameters: http://www.thingiverse.com/thing:56333