Vibration control inside a cabinet

One point, the shallowness of the bottom cup doesn’t affect frequency of isolation as Barry theorizes. It affects effectiveness of isolation. Roller bearings aren’t really analogous to mass on spring devices. I.e, a very shallow concave surface provides better lateral isolation (ease of motion) but worse rotational isolation, since the component cannot rotate much when forced by rotational forces, it rotates by climbing the walls of the concave surface. Thus the shallowness is a trade off, it can't be too shallow or too concave. You could probably get really good horizontal isolation with flat bottoms and flat tops, you would just have to constrain the bearings from moving too much, and the component would have to be perfectly level and balanced. It could be done. So you got your roller bearings for the horizontal plane and 3 rotational directions and you got your springs for the vertical. Then all you have to worry about is how you mount the whole contraption on the floor and how to mount the thing on springs. Ah, the art of isolation.

Where there is motion there can be no isolation. Ah, the art of isolation.. choose your paint color made from all the various materials and their geometric shapes all interacting with their various shear speeds and reflected angles most back into the path of what's supposedly being isolated.  Tom

Tom, while I can appreciate your persistence in this matter, apparently there CAN be isolation where there is MOTION as demonstrated by LIGO, the 4 km long interferometer experiment to detect gravity waves - the most critical portion of which is the vibration ISOLATION system - which BTW was successful last year in detecting gravity waves, you know, those teeny tiny physical waves left over from the Big Bang with amplitudes the size of atomic particles. HEL-LOO!  So, apparently there CAN be ISOLATION where there is MOTION. I also submit as evidence all the testimony from users of vibration isolation devices on this thread. Have you NOT been paying attention?

It definitely seems that one of the biggest challenges is, as Geoff suggested, putting these ideas all together in a stable manner that doesn't raise components so much that they no longer fit in the rack. 

I’m glad you mentioned that, Todd, as one of the really big advantages of my "new style" cryo’d springs is their size, being only about 3/4" compressed in height. So they will Fit just about anywhere. You could even use them on submarines, one supposes, where space is a supreme issue. Hel-loo, US Navy! Are you listening? The other advantage of my mini springs that may not be obvious is that their lateral stability is greater than for larger springs, due to lower center of gravity when under load. Thus, they can be placed directly under components without all the trouble and expense and SPACE of having to place boards underneath the components as in the old days. My Promethean Base, for example, sorry no longer available, employed springs that were about 2 1/2" compressed height.