Case studies: Measurement System Brings CMM to Life
January 28, 2006
For more than 30 years, Spectralux Corp. (Redmond, WA) has provided lighted displays, data entry keyboards and avionics assemblies for the defense and commercial aerospace industries. The company designs and manufactures panels-lightplate and keyboard-for first- and second-tier aerospace companies.
Spectralux Lead Inspector Gary Freshour says their previous measurement system was not very accurate-they used calipers or sometimes just estimated. For visual inspection requiring magnification, they used microscopes.
"We were contacted to assist with measuring some of the materials that they process and receive from vendors. They did not have any noncontact measuring capability in their QA department," says Mark Arenal, president and sales manager of Kinemetric Engineering LLC (Laguna Hills, CA).
The solution was to mount Kinemetric's MultiProbe 100 on Spectra Lux's manual coordinate measuring machine (CMM) which was getting minimal use. This allowed Spectralux to measure parts in a noncontact fashion using the existing CMM computer and display capabilities. Kinemetric arranged a footswitch that allowed measurement points to be targeted and taken, allowing the operator to keep both hands free for positioning the CMM.
"We're seeing a lot better product coming through now than we would have before," says Freshour, who implemented this system. He says the MultiProbe offers versatility, accuracy and variable magnification. It also provides visual inspection for the qualitative aspects of the parts being measured and a higher confidence level.
"We're able to do things that we couldn't have done before because of the tooling," Freshour says. Spectralux uses the system where flexible or soft materials would give way, such as gaskets or diaphragms, or for measuring inclusions that are not accessible with a touch probe. They could not accurately measure flexible or 2-D materials and features before.
"It also has a great magnification range on it," adds Freshour, which allows him to closely inspect for blemishes or imperfections, whereas before only a low-magnification microscope was used. The higher magnification also allows previously elusive surface imperfections to be photographed and small radii to be measured, says Freshour. It also has allowed them to photograph and document special features, showing a much higher level of detail. The variable lighting control helps when examining tinted lenses. Occasionally he uses it at final inspection for measuring laser-etched indicia. Additionally, their CMM is now more productive.
"Basically it brought their CMM to life," Arenal says. Because CMMs are such an investment, the MultiProbe allows the machine to be used more frequently and effectively. The MultiProbe changes most CMMs from a contact measurement machine into a noncontact measurement and inspection system in minutes. It contains a motorized optical zoom lens that provides magnification from 44X to 288X; a high-resolution color video camera and an adapter to accept a Renishaw PH6 probe head. The unit incorporates LED ring illumination with an option for fiber-optic ring light or coaxial illumination.
Spectralux's Material Review Board coordinator uses it frequently for its ease in measuring distances and features that do not require a three-dimensional coordinate system. Furthermore, visual images under magnification have helped provide documented evidence when working with an argumentative vendor, Freshour says. However, the company thinks there may be more benefits in the future.
"We're still finding new ways to use it all the time," says Freshour.
"It was a learning experience for us, of course," Freshour says. "We're just growing in new directions now."
Kinemetric Engineering LLC
- The motorized optical zoom lens provides magnification from 44X to 288X.
- The system can be used where flexible or soft materials would give way, such as gaskets or diaphragms.
- It measures inclusions that are not accessible with a touch probe.
- The MultiProbe expands CMM capabilities and converts CMMs into a video-based measuring system.