Computer Disk Testing & Pack Writing

Professional Instruments Company air bearing spindles played a fundamental role in the development of mass storage devices for the computer industry. In 1959, before disk memories were developed, we produced memory drums for Sperry-Univac. Our spindles played a vital role in IBM’s development of the 14-inch disks and packs, as well as Dysan’s floppy-disk drives. The leaders of today’s disk-memory industry depend on Professional Instruments Company’s spindles; they are a stable and constant influence in this capricious field. The incredible accuracy of the BLOCK-HEAD® air bearing spindle allows computer disk drive developers to test, write and retrieve information on a near-perfect axis of rotation. These properties have enabled a wide range of developments including the one sitting in front of you now. The fractional-millionth accuracy of both the BLOCK-HEAD® and ISO line of spindles makes Professional Instruments Company products the standard of the industry. A typical Professional Instruments Company BLOCK-HEAD® disk testing spindle has radial asynchronous errors of 2 nanometers.

Shown here is a small selection of our disk testing and pack writing spindle products. BLOCK-HEAD® spindles and ISO spindles are used as the axis of rotation. A wide variety of chucks hold single or multiple disks. Professional Instruments Company chucks are available as covered, coverless, self-centering, and automatically balanced. We have been asked to solve almost every imaginable problem associated with holding disks for testing and writing.

The fact that Professional Instruments Company has been an active player in the diamond turning market, including the diamond turning of computer disks, allowed us to become experts in the kinematics of disk holding. Our chucking systems are unique and complement our ultra-precise bearing perfectly. Motor drives and encoder feedback are included with all of our current disk testing spindles. The motor rotor is attached directly to the air bearing rotor. The encoder is attached directly to the same rotor shaft. Professional Instruments Company’s uncompromising attitude towards error motion ensures that any spurious motions from the drives and feedback are minimized. These are the same motors, encoders, and drives that allow us to directly motorize spindles for the world’s most accurate aspheric generators. The multi-disciplinary approach Professional Instruments Company brings to design of air bearing solutions ensures that our customers are buying only the finest available solutions to their problems.