Established in 1952

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The Geostep™ 3400-10

Technical Data Sheet CMM-26, Page1

The Geostep™, model 3400-10 has ten ultra precise spheres permanently mounted on the centerline of a very rigid beam. This one universal tool is the only device required to fully calibrate most Coordinate Measuring Machines. After the Geostep™ 10 is properly calibrated, it becomes a fully traceable secondary standard. In addition to its ability to perform a full-scale machine calibration, the Geostep™10 will do an interim or Monday morning evaluation of the machine in just a matter of minutes.

When trouble shooting to locate problems that occur with the machine's performance, the data collected from the simple in line design of the Geostep™10 are very easy for the calibration technician to interpret.

The unique three-dimensional characteristic of the spherical artifacts used on the Geostep™10 make them the ideal geometry for C.M.M. evaluation. There are no flatness or parallelism errors. There are no alignment or cosine errors of either the artifact or its positioning on the machine. This is because the origin of the spherical surface is perfectly defined by its radius as a single infinitely small address in three-dimensional space.

The Geostep™10 is a Ball Plate. It is a Ball Bar (Dumbbell). It is a step standard.

It weighs only 20 pounds (9.0 kg), but the unique design makes it extremely rigid. All of the spherical artifacts are arranged on the center line or neutral bending plane of the beam. Any minute bending that does occur due to gravitational attraction or probing force will cause only very small second order cosine errors in the true position of the spherical artifacts.

The beam or frame of the device is produced by the special Stable Cast™ process. This near net shape process creates a metallurgically sound structure with very little retained austenite, so that its long term dimensional stability is assured.

The rugged beam of the Geostep™10 is 1.5 inches (38.1mm) thick and 4.0 inches (101.6mm) wide. The overall sphere center to sphere center dimension is approximately 850mm or (33.46 inches). The substantial reach of the Geostep™10 is more than twice that of a standard 400mm (15.75 inches) Ball Plate. A single technician can do the entire set up and calibration of the machine, because the Geostep™10 has a weight of less than 20 pounds (9 kg).

Each of the ten sphere center to sphere center dimensions are approximately 85mm or (3.34 inches) apart. These ten spheres provide 45 sphere center to sphere center dimensions. These center to center dimensions are intentionally varied from sphere to sphere. This feature is used to prevent any possible systematic errors in the scale system from falling into a matching pattern with the step standard. The ten 0.748 inch (19mm) diameter reference spheres are exactly the same diameter and spherical within less than 5 microinches (.13 micro meter). The standard spheres are produced from extremely fine grain, stainless steel that is hardened to 58 HRC and is thermally treated, for long term dimensional stability. We also offer fine grain, high-density ceramic spheres.