For more than half a century, Birmingham-based Precision Micro Ltd (www.precisionmicro.com) has pioneered innovative photo-chemical etching production techniques, and the company is now established as a respected global supplier of custom parts to a wide range of high-tech industries, including automotive,aerospace, defence, electronics, medical and precision engineering.

The company operates a rigorous programme of continuous quality improvement (CQI) throughout all departments, to ensure that product and manufacturing standards continually improve.

This CQI programme recently prompted a search for an extremely precise vision-based measuring system that would further enhance the company’s quality control capabilities while also ensuring that its inspection department could keep pace with increasing production volumes.

Precision Micro’s Lee Weston said: “As a direct result of our CQI initiatives, we can maintain repeatability levels approaching six-sigma standards.

“To support our quality activities, we have an in-house inspection department that covers disciplines such as material hardness, mechanical properties, surface roughness measurement, material analysis and dimensional measurement.

“The data generated from this facility helps to drive our process-control systems. To help our inspection department keep pace with recently increased levels of production, and to ensure it can accommodate future production rises, we recently decided to buy another optical CMM to add to our existing collection of five machines, three of which are Mitutoyo models.

“The oldest of our Mitutoyo CMMs has now been in operation for 15 years; it has never broken down and is kept busy 24/7. Aware of the technical progress made in the field of optical CMMs, we looked at machines from several manufacturers.

“Having deliberated the merits of several machines, we came to the conclusion that Mitutoyo’s Quick Vision Stream Plus was the ideal machine for our high-precision fast-throughput needs.

“Although the quality of our parts is of paramount importance, speed of inspection is also crucial. Given our current high levels of output and expected increases in production, it helped that the Quick Vision Stream Plus is 83% faster than our existing Mitutoyo models; it also has a larger bed, allowing us to load more components for inspection.”

Automotive work

An example of the advantages Precision Micro has gained by using its recently installed optical CMM from Andover-based Mitutoyo UK Ltd (www.mitutoyo.co.uk) is the inspection time savings the company made on one of its commonly produced automotive components.

Mr Weston said: “We can now perform a precise and detailed 100% inspection routine on a quantity of these components in just 4hr; this previously took us 16hr.

“As we need to perform 100% inspection on more than a million automotive parts each month, the accuracy and speed of the Quick Vision Stream Plus has removed the potential for inspection bottlenecks; it has also ensured that our dimensional inspection capability remains ‘future-proof’.

“We also bought Mitutoyo’s MeasurLink software. This has allowed us to network our new machine, our existing machines and all of our hand-held measuring instruments — regardless of brand. Now, we not only achieve rapid seamless data collection but also undertake efficient remote data analysis.”

Mitutoyo’s vision-based measuring systems are available in a wide range of sizes and accuracy classes to cover most precision applications; and in addition to built-in high-performance vision probes, contact probes are available on some systems to extend the range of measurement applications.

The Quick Vision Stream Plus — as purchased by Precision Micro — is part of a range of 3-D CNC machines that offer accuracy in the 1.8µm class. The use of a high-intensity-LED stroboscopic image-capturing technique, which operates while the measuring ‘stage’ is moving, means that the machines are highly productive on most workpieces.

This dynamic measuring technique eliminates the time needed to accelerate, decelerate and then hold the stage motionless while a measurement is made. Meanwhile, programmable ring lighting provides flexibility with regard
to lighting direction, angle and intensity — regardless of the slope of the workpiece surface.

This allows maximum surface contrast to be achieved for best imaging resolution, and hence improved accuracy on even the most problematic of workpieces.

A fixed-bridge moving-table design provides optimum rigidity, while a programmable power turret provides control of magnification for optimal viewing.