The Quadrasphere

The Quadrasphere is a unique device for solving special problems in kinematic couplings design. The standard off the shelf version of this device consists of a one quarter section of a one and one quarter inch ( 1 ¼”, 1.25”, 31.7mm ) diameter hard stainless steel ball. This rather large spherical diameter gives these devices high load carrying capacity in a very limited space. The spherical contact with a cylindrical or a flat surface forms a truly kinematic couple. Two of the quadraspheres are usually epoxy glued into a trench and machined into a base or platform of the kinematic couple. See Figure #1.

The QuadraSphere

The Quadrasphere

The ends of the Quadrapheres are truncated off to remove the sharp points which will greatly facilitate their mounting. The hard Martinsetic stainless steel that the ball is made of has an ultrafine grain structure. It is hardened to 58 HRC minimum. This material has an extremely high tensile strength of 283,000 pounds per square inch. Custom made Quadraspheres can be produced in almost any material, to meet special needs for high temperature, extreme corrosive resistance or electrical or magnetic properties. The Quadrasphere can be produced with any desired spherical diameter. Additional features can be incorporated in these devices, such as threaded tie down holes.

The threaded holes can be vented to make this device compatible with high vacuum requirements. The unique two points of spherical contact mate beautifully with a precision cylinder to form a true kinematic couple. The same design will mate perfectly with the two flat surfaces of our standard split male kinematic vee, our part # SVB-2000-SM. The fact that the two large spherical surfaces are two separate pieces, in this design, makes these parts perfect for use in a “Split Kinematic” coupling (See our technical paper “Split Kinematic Couplings without Abby offset- See Also Dr. Alex Slocum’s M.I.T. paper on split kinematic couplings).

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