Here's a robot video that I found interesting:
Bench Test of my 3d printed rear differential. Printed on a MakerBot Replicator 2 at Medium settings: 2 shells, 0.2mm layer height, and 10% infill density. The buckets have a combined weight of 70 pounds (30 kilos). At the end the chain slips off sprocket and got twisted, with ended testing for the day.
The Differential still works fine.
Thatnks to Jordie Smith for filming
By Michael Curry