Harold Arneson

Harold was born in Minneapolis, Minnesota in 1925. He studied mechanical engineering at the University of Minnesota. He served in the Air Force during WWII and, with his brother, Ted Arneson, started Professional Instruments Company in 1946. The company entered the ultra-precision engineering field in 1960 by fabricating hollow spherical gyro rotors requiring microinch tolerance. Harold became convinced that hydrostatic air bearings were the optimum route to the accuracies necessary for future requirements in manufacturing and gauging. He invented the dual-hemisphere spindle that became well known in applications at the Oak Ridge National labs. To overcome the disadvantages of the hemispherical configuration, Harold improved the design and patented the BLOCK-HEAD® spindle in 1969. This spindle became the most widely used ultra-precision air bearing spindle in the world and is standard equipment on Moore Tool diamond turning machines. The BLOCK-HEAD® has seen applications in a wide variety of fields from basic physics research in the value of the gravitational constant to the fabrication of intraocular lenses for cataract surgery.

Harold did more than invent air bearing spindles; he contributed to the tool box of precision engineering by donating ideas and equipment for humidity control, sphere lapping, cylindrical grinding, design of bolted joints, balanced-force couplings and bearing error analyzers. Tooling that Harold built was at the heart of many major projects at IBM, Honeywell, 3M, Control Data, Memorex, Bell Labs, Polaroid and others. These tools have served as models for several generations of toolmakers and engineers who are continually working to achieve the next decimal place.

Harold died at his retirement home in Fort Myers Beach, Florida in May of 1995. He was a gentleman, a scholar, a scientist, a master craftsman, and a great teacher. His life was well spent in the pursuit of knowledge and its practical applications.