[blt]

This is the best technical education video I've ever seen. If all information were available in such an easy to understand form, the world would be full of geniuses.

The level of effort is astounding. The "support" part holding the spokes looks cast. They couldn't have possibly cast that part specifically for this video... could they?

[niels_olson]

casting one-offs with a disposable form (wax, styrofoam) isn't particularly difficult or expensive. They use big basins full of super-fine sand: a great insulator and the grains are too tightly packed for the liquid metal to flow into the tiny spaces between them. We used to do it in high school shop class.