Lego #57518 technic link Caterpillar track

thingiverse

This is one link of the Lego (R) caterpillar-track (or tank track). I did my best to take the measures... EDIT Sept 5th 2019: The new V7 Version has a flat surface at the top of the bolt, so that the links slide into each other in a 90° angle easily. I also modified the underside, making printing a lot easier. You´ll only need two supports as shown in the picture (in fact, I even printed it without supports at all, but had to cut away two tiny parts with a knife...) - V1 is the original model including the clip-mechanism, that tends to break easily, when printed with FDM Printers. - V2 is a version with two holes. So you cut some pieces from 3mm filament and use it as the bolt. Theres a version with a chamfer, so you can use a soldering iron to make a head for your bolt (hotpress version) or simply use glue to fix the bolt.