ssuds

Tiny! Like <4”. It would be near impossible to design something spinning so fast at a larger diameter

Yup, you nailed it. This is exactly what I meant when I said “tearing themselves apart”

In a past life I worked on a rocket engine turbopump that spun at 160,000 RPM. It’s crazy to visualize how fast that is. The stresses in the metal are so high that we needed speciality alloys made exclusively for us. The parts are literally ripping themselves apart.