An animated model of what we called a 'Cotton reel tractor' that we used to make as children.
We used to make these from old cotton reels, by carving 'teeth' around both edges, then adding a piece of candle to act as a washer, then thread an elastic band through, with a matchstick at one end and a 'lolly-pop' stick at the other.
I have added a 'C4D motor' to this model, so it is animated. I have also made it interact with the (added) 'bumpy base'.
It was modelled in Cinema 4D and I have added an .FBX version too, all with lights, camera, materials and action...
I have also printed this model as a 3D printed working toy - You just need to add an elastice band and 'wind it up' and let it go...