There are three primary options available today for shaft measurement: optical, tactile, and a combination system. The optical systems have become common over the past few decades because of their flexibility and speed. So how do you choose the best option for your specific application?
When a shop begins the manufacture of rotating shafts, they frequently turn to their conventional CMM for part validation. However, this is often a case of using the tool that is at hand, rather than one designed for the job.
The simple shaft is one of the ubiquitous items in every mechanical system. Shafts contain a number of key functional elements, such as splines, tapers, grooves, threads, cams and gears, which all have associated critical dimensions to allow these mechanical systems to perform the function for which they were designed.
Pick up any shaft or threaded fastener. How are you going to check it? An outside micrometer is most often the go-to tool for measuring diameters. A height gage or drop indicator could be used to check dimensions between part features, while an optical comparator is a good way to inspect thread forms or measure a groove width.
You may be unfamiliar with the term “optical shaft metrology.” But you’ve no doubt experienced the advantages of this technology. Traveling by car or airplane, for example. In fact, it might surprise you to learn that anytime you’ve used a machine with an electric motor, a turbo charger, fuel injection, precision bearings, transaxles or spindles, chances are good you’ve benefited from optical shaft metrology.