Re: ATM "Frozen" liquid mirrors

[PAugello@aol.com]

Gerry:
     The air bearing for the platter of my turntable is of the thrust type
you describe, but for centering it just uses a nubbin pressed up through the
center of the bottom plate which fits into a recess in the spindle, which is
pressed through the top plate.  A belt-drive and that's it.
     If anybody wants more details....

Take care,
Peter Augello

In a message dated 97-02-21 10:06:51 EST, suegerry@mut1.muscanet.com (Suzanne
Sarlette/Gerald Pearson) writes:

<< Alternatively, it might work better to use a thrust bearing (2 flat
 surfaces separated by a film of air) to support the weight, and a
 cylindrical bearing to keep the axis of rotation centered.  It should be
 much easier to machine a _good_ thrust bearing than a _good_ conical
 bearing, but then it might turn out to be _more_ difficult to machine a
 good cylindrical bearing.  
  >>