There is some assembly required and probably some filing depending on how accurate your printer is. Extra materials include 4mm diameter dowel for the axles, 1.5mm rod of some sort for the control lever, duct tape or electrical tape for the lever hand grip, a screw to hold in the lever, and some popsicle sticks for whatever you want to have on top of the bogey set. Paints and glue will also be quite handy. This is designed to print without support.