Quote from: bonenick on Jan 14, 2017, 04:22AMTo a tbone novice like me, please explain how these are different from the traditional rotors
Hopefully Mike will clarify the details of his new setup.
To provide you some background, here's a bit about general design of traditional rotors.
Generally, traditional rotors have a two sleeves in the center of the rotor shell, one on each end of the rotor. In theory, the rotor is SUPPOSED to spin in these two sleeves, and NOT actually touch the outer perimeter of the rotor with the inner perimeter of the shell. And, again generally, this is done by machining the sleeve and shell with very slight tapers, then honing the rotor core into the shell.
In practice, some honing is not as careful as other honing. In practice, the sleeve bearing wears over time, especially if the player does not oil the rotor properly (which includes oiling regularly.) So, in practice, the outer perimeter of the rotor DOES touch at least a bit on many horns, especially older ones. When the touching gets too much, the rotor needs to be rebuilt (plated or sleeved and rehoned) or replaced. Sometimes, if the touching is noticed soon enough, the sleeve can be snugged back up with very finicky swedging, and extend the life of the valve.
That should be enough to prepare the way for Mike to explain what is so great with his design. I think I have a pretty good guess already, but that's all it would be. I'm impressed without even knowing the details.
The high revolutions per minute (rpm) are impressive because they magnify any defect in how concentric the shell, outer perimeter of core, and spindle are, and also magnify any out-of-balance condition. For instance, any looseness that might have caused the kind of buzzing that was asked about before would NOT let a rotor spin this fast; the bearing would self destruct. I'm pretty sure trying to spin MY old rotors over a couple hundred RPM inside the case would damage them enough to need rebuilding!
Don't be misled by my comments or others about hypothetical vibration possibilities: the REAL physics of what Mike is doing have far more tangible benefits than these other effects could possibly have. Having assisted in the rebuilding of a few french horn rotors, I'm very impressed with what Mike is doing!