About Control Gaging
, headquartered in Ann Arbor, Mich.
Attribute gaging is generally indicated for applications where the life of the tool that generates the gaged characteristic is predictable, and where anticipated process variation is relatively low (producing a CpK or CP of 1.
Variable gages are also indicated for three additional types of applications: where you can expect to optimize tool life and uptime by gaging the part and making corresponding machine adjustments; where scrap rates and loss of productivity are high; and where process variation is expected to be relatively high - measured by a CpK or CP of 1.
Finally, air-to-electronic gaging systems should be considered for applications where low initial investment is a requirement and flexibility is not.
Allison Engine Co, formerly Allison Gas Turbine Division, General Motors, saw that Kurt's modular gaging could provide other benefits as well.
Allison, a manufacturer of aircraft engines, had a new turbine blade program that required accurate fixture gaging to measure very complex geometries on a family of turbine blades.
In applications where there is interference between the part and the gaging contacts, the air/spring actuated linear bearing slide is used.
Kurt also manufactures modular fixtures with digital or analog dial indicators, although Mr Stout says these systems account for less than 10% of the company's gaging business.
The cost savings possible using the modular gaging are illustrated by Allison Turbine Engine Div, which purchased seven modular fixtures to replace dedicated gages.
US automakers have always thought in terms of hard, dedicated gaging.
The grinder can't compensate itself for process variation-that's why you use in-process gaging.
You need gaging that is stable, reliable, and stays set once its calibrated.
With turning (particularly hard turning) challenging grinding, in-process gaging is moving into turning.
Gaging systems range from the simple hand-held plug gage with air column or digital readout to more complex, fully automated systems with distributed processing of related activities such as machine monitoring, robotics, and information management.
Usually, measurement occurs after cutting stops and is better termed "post-process gaging.