This scene was rendered in Cycles. The model itself was a fully-parametric Grasshopper project, which took 199 components. Most bearing sizes, roller count, and tolerances can be set, using a scant 23 sliders : )
I thought it would be fun to do a render. For the background, I actually rubbed oil on a piece of paper bag, and then scanned it. LOL!
No, the bag surface is dead-flat.
(Sorry about the copyright, but there are too many scrapers.)