A newer version of this design is available here: http://www.thingiverse.com/thing:1911788
This is my first design with moving parts, a fully customziable simple escalator. When leaving out the steps it can also be used as a conveyor belt or maybe tank tracks without the chassis.
Before printing everything it is best to print a couple chain links to see if they work. When using multiple links per step the chain link with the socket on top can be used to connect both the horizontal and vertical parts of one step, the link without the socket can be used in between. The pulley should be big enough that the chain with the mounted steps can bend around it, so it is best to print one of the pulleys next to try that out. The pulleys with the mounted chain are placed on the axes in a way that the hole in the chassis aligns with the square hole of one of the pulleys. Make sure the pulleys rotate easily. You will need 6 pins to assemble the chassis and mount the handle. Inserting the pins can be quite tough, I did it carefully with a hammer. When the chassis is assembled the crank can be joined with the handle and mounted trough the hole of the chassis with a pin.