I found the tank tracks for timmiclark's "MR6 - Mini Prototyping Tank Robot" (https://www.thingiverse.com/thing:2753227) to be very tedious to assemble. Each of the 64 pieces needed must be pinned together into a track by making small pins out of filament. These small pins caused great amounts of friction, slowing the tank down, as well as eventually snapping and needing replaced. I replaced them with 1.75mm rebar wire, which is far more durable, but still caused lots of friction. This model was my solution to the friction problem. It's one circular track which can be printed in most any flexible or semi-flexible material, such as Ninjaflex/Semiflex, eliminating friction between links since the links are no longer needed. Just print, then pull the track over the cogs on the tank and it will snap into place. Happy Printing!