Especially enjoyed the part where they fabricate a custom 500 watt, 54-pole (if I counted right) out-runner alternator essentially from scratch. Sheet metal was cut!
That was almost as hard as cutting the blades. The tricky part was that the sheetmetal when plasmacut deforms so much and so fast that you have to really move the plasmatorch upwards and out of the way or you'll have a material strike. This required intervention into the guts of the plasmacutter driver to pick up the voltage across the arc which is a good way to gauge proximity. Keep that voltage constant and you're going to be a relatively constant (+- .5 mm) distance away from the material you're cutting. The cutter used was a 12KW Thermal Dynamics unit, it would go through 1/2" like butter, very nice tool.