BLOCK-HEAD® Air Bearing Spindle Specifications

(at 150 psi)

The BLOCK-HEAD® family of air bearing spindles (named for their short, blocky shape) combine rotational accuracy with extremely high stiffness comparable with that of heavy-duty ball bearing headstocks. These spindles are suitable for accurate support of overhung loads, and their unique combination of accuracy and stiffness makes possible direct machining to optical tolerances and finishes.

BLOCK-HEAD® spindles have been used successfully from less than 50 psi up to 200 psi, and have shown no signs of instability. They will operate equally well in any position, over a wide speed range, and in a variety of environmental conditions. Add-ons such as motors, chucks, mounting plates, and custom tooling benefit from the correct nature of the BLOCK-HEAD® design. Accessories can be close-coupled, tightly-held, and non-distorting.

Load capacity and stiffness are approximately linear with air pressure.

Ultimate load capacity is measured when metal-to-metal contact is made across the bearing surfaces. Working load capacity is half of the ultimate load capacity. Rotor weight must be included as part of total spindle load.

Axial and tilt loads are supported by the same bearing surfaces. Consequently, a load applied in one mode reduces the other mode proportionally.

High speed or high inertia applications require rotor containment. Maximum speed is dependent on application. Consult Professional Instruments for further information with regard to speed.