We had 6 of them, I can't recall which model, but the rotor was about 3 foot in diameter.
they were normally problem-free, but the way they were installed in the building made them a nightmare to work on
We brought a rotor down for a pin change, and the guy who rebuilt it used 4 pins to keep the discs separated while pulling the old pins off. He forgot to remove one of the pins when he put it back together. When they started that machine back up the whole building started shaking.
We just called them “Bug Smashers”. Yes, at 15,000RPM a slight inmalance on the motor shaft is going to shake the house down. Then it becomes a SWECO Sifter without the isolation dampening spring coils.