Re: [CAD_CAM_EDM_DRO] Re: Cheap 56,000RPM milling upgrade (not a dremel :)

cnc_4_me wrote:

>
>
>>The bearings are AIR! No balls; steel, ceramic or other. The
>>
>>
>spindle
>
>
>>flies on a
>>cushion of air, and only air. Technically, a "fluid film bearing"
>>
>>
>in
>
>
>>which the fluid
>>is dry, filtered air. Rather amazing, the friction is about 1
>>ten-thousandth of an oil-journal
>>bearing, and about 1/1000th of a fine ball bearing. If the
>>
>>
>clearance in
>
>
>>the bearing can be
>>held to a fine tolerance, the stiffness can actually be GREATER
>>
>>
>than a
>
>
>>ball bearing,
>>which is still pretty hard to comprehend.
>>
>>Jon
>>
>>
>
>
>Do you know approximately what the shaft diameter is, were it is
>supported by the air bearings.
>

Roughly 3/4 inch. The whole spindle is a smooth 3/4", including the entire
motor rotor. There is a big "flange" on the back end which is the thrust
bearing.

> And what is the rated continuous
>running RPM of this unit.
>
>

At least 80,000 RPM, but I was never able to get a precise spec sheet from
Westwind, as this is a pretty old unit.

Jon