The GSG Zero Spindle offers various methods of holding a part on the outside feature during rotation.  The charts show the 4 major methods collet, 3-4 jaw chuck, and external off lead lock.  These methods can be combined with various measurement methods and provide the user with a robust and repeatable way of inspecting ovality, runnout, diameter and true position of round parts.

For Inside Diameters or Female Threads - Zero Spindle PDF Link   Data Sheet

THE ZERO SPINDLE SYSTEMS

The GSG Zero Spindle System is accurate (T.I.R less than .000020"), rugged, versatile, and economical. It can chuck on a wide array of parts, ID or OD.
The I.D. features collets, push arbors, or 3-jaw chucking capability. 

The OD features ODC collets, 5C collets, or 3 jaw chucking capability. GSG can further enhance the Zero Spindle System through the use of extended jaws for
special lengths or 4 jaw chucks. The system also makes use of GSG's exclusive line of Lead Lok products, which "lock up" on the pitch diameter of internal or
external threads. 

All of the above accessories can be mounted horizontally or vertically and, when used with indicators, can be mounted so as to swing in/out to check runout,
concentricity, and squareness. The Zero Spindle System can even be configured into a "hand held" model, or be used between centers.

All configurations can be ordered with conventional masters to recalibrate the system or be used with special part masters, which simulate the actual part being
 inspected. This makes the Zero Spindle an easy addition to your specific quality program. GSG provides a download for Cadpac, which facilitates the design
 of tooling and fixtures around the base unit. DXF versions can be provided for other CAD protocol. GSG can also design & build true position gages, or
manufacture to the customer's design specifications.

A complete inspection system for checking concentricity, squareness and roundness.  With the many accessories manufactured exclusively for the
Zero system (spindles, arbors, precision chucks, magnetic and tapped face plates), GSG provides everything needed to build around your own application