You point at a part of it and start explaining further anyway. “The shaft connected to this concave cone is already spinning. These rounded wheels between it and a similar cone on the other side transfer force across the gap. If the wheels are angled, one cone will spin faster and the other slower. Usually you’d use a belt, I think, or some sort of planetary gearing, but this would be easier to make.” You look over some notes that appeared on the page. They’re completely illegible. “I’ll use it to figure out an ideal balance of speed and torque Twilight’s spells can produce, then make a fixed transmission with magnets off the required ratios, for reduced maintenance. For the test we can just use flywheels as loads. Oh, I’ll need to design a way to control this.”