Simplified CMM inspection provides a flexible approach to more productive quality control

Two LK Metrology CMMs, have substantially replaced two lesser capacity, 15-year-old machines in the inspection room at WLR Precision Engineering.  The new CMMs come with LK Launchpad, an icon-driven, touch-screen operator menu, and a network of viewing screens and tablets. In only a few clicks, the operator can select from a variety of inspection programs and set the part on the machine table for examination. It adds versatility and allows non-expert CMM operators to operate the system. Results can be shared between screens, tablets, and other networked devices for quick access from anywhere.

WLR is recognised as an all-encompassing service provider by its clients, as it oversees practically every contract. Each part's value is enhanced by rigorous metrology, frequently involving 100% inspection. Industries such as oil and gas, pharmaceutical, medical and scientific apparatus rely heavily on the accuracy and uniformity of parts delivered.

"The increasing confidence that our customers have in the accuracy and consistency of components they receive from us has resulted in our winning considerably more business in virtually every sector that we serve." - Tom Parr, WLR Sales Manager

The procurement of the first LK CMM in 2015, an AlteraS 15.10.8 with a measurement volume of 1,524 x 1,016 x 813 mm, helped increase confidence in WLR's services. It revolutionised quality control at the Wilford factory, making measurements and inspection reports faster, more efficient, and less labour intensive. The equipment was purchased due to an increase in component orders from major customers and the need for more thorough inspection and reporting. 

The CMM's large table area, roughly 1.0 x 1.5 metres, allows it to accept up to 12 identical components for batch inspection.  It's odd to see a measuring equipment nestled with many components, but the subcontractor says it's completely possible. On average, a day shift can inspect five batches with a load time of around five minutes.

After the components are installed, an inspector hits a button and each one is measured in a two-hour automated cycle. So the individual can work on other metrology equipment for most of the day and the inspection time is known. The old system required an inspector to sit by a CMM all day loading each part individually prior to every automatic measurement cycle.

Previously, preparing reports by hand on 12 inspected components took around three hours, which was both time consuming and tiresome. Now, CAMIO's ability to fully automate the task results in significant savings. In minutes, a thorough inspection report encompassing 30-40 critical dimensions per part is generated, with colour-coded content for non-conformances. The report data is exported straight into an Excel spreadsheet via a WLR-formatted CSV file.

All of these benefits have increased WLR's inspection and reporting efficiency, allowing the subcontractor to handle an increase in orders from several customers. A half dozen products ordered by some clients three or four years ago have increased tenfold today. Automation in the inspection room and on the shop floor allowed this to be done without adding extra staff.

LK Launchpad automates and de-skills inspection

By May 2021, additional batch measurement capacity would be required. Additionally, a demand for in-process inspection of a specific family of components was added for one customer. This time, a smaller LK AlteraS 10.10.8 was purchased, with a working volume of 1,016 x 1,016 x 813 mm, together with the latest CAMIO 2021 and the LK Launchpad software. The simple-to-use graphical interface enables not only the two WLR quality inspectors and quality manager Tony Blood to load components singly or in groups of up to six, but also the ten dayshift and five nightshift machine operators to do so.

Inspecting a component is easy with Launchpad's basic graphical menus and icons on a screen positioned by the machine. The operator can find the component by searching for the customer's name, part category, or immediately calling up the part with machining details. It's easy to set up the CMM with the help of 12 mm thick aluminium fixture plates fitted across the granite table. It is easy to use, just position the component in the numbered spot on one of the fixture plates and start the measuring programme by tapping a button on the touchscreen.

The same inspection results are available on networked tablets used by machinists on the shop floor, and the information may be shared with other devices. It allows for more thorough inspection, reduced downtime, and makes machinists more invested in the process. The next stage will be to allow operators to be notified via tablet when the measuring cycle is complete, eliminating the need to keep track of time.

A pre-drilled location plate on the bigger LK CMM granite helps load components in batches or individually prior to inspection. Using Launchpad software, both devices can be utilised for batch or operation inspection by shop floor workers, enhancing quality control department efficiency.

CAD-based CMM programming

The ability to programme the machines directly from CAD was also introduced with the first LK CMM. For a customer, it was occasionally necessary to make a first-off component in up to six machine tool operations, then return the part to the inspection department to be measured and rectified if necessary. After finishing machining, the component was used to teach a measuring software into an older CMM. The DMIS inspection cycle for the LK CMM can now be created from the same CAD model using LK CAMIO software, just like a metal cutting project is launched from a digital model of a customer's component.

All inspection processes for both LK CMMs are now programmed in CAMIO, which also analyses the acquired data and reports the results automatically. In addition, the measurement programme allows the first-off portion to be examined quickly. The programming time is faster than before, but the major benefit is that it is done off-line, freeing up the CMM for component inspection. Using a Renishaw SP25 scanning probe or a Nikon LC15Dx laser scanning head instead of a touch-trigger probe has increased measuring throughput substantially.    

On the implementation of the successful metrology upgrade at WLR, Quality Manager, Tony Blood commented, "Our new measuring processes can be used by personnel with a wide range of experience levels. The high degree of automation plus the ability to increase speed by scanning as well as touch-probing have helped us save time and remove inspection bottlenecks. 

"Automation and deskilling of operations have also allowed us to enhance inspection efficiency without adding to our headcount. Added to this, every day there is a further economic advantage through the ability to run the CMMs unattended for up to two hours at the end of each day shift due to our strategy of batch loading."

Mr Parr concluded, "The parts we produce typically range in size from about 5 mm square up to 115 mm in diameter by 250 mm long. 

"At one end of the scale they are milled, turned, ground, spark eroded, and diamond lapped from free cutting brass, aluminium and stainless steel, but very often they are machined from the toughest of alloys including Inconel 718, Invar or Hastelloy.

"Consistently high precision is the watchword here, with machined tolerances normally of the order of ± 25 microns but exceptionally down to ± 3 microns, if necessary.

"Nearly all components are inspected on our highly productive LK CMMs. There is enough spare capacity now to provide our customers with an additional service whereby, if required, some components that we do not manufacture for them are also inspected here and certified by us.

"Additionally, the new metrology room impresses customers when they visit us and improves their perception of the top quality, high value components we produce."