Nasmyth Arden Case Study

Nasmyth Arden, a Solihull-based specialist in the manufacture of aerospace components, has purchased a SmartScope CNC 800 multi-sensor shop floor measuring system from OGP UK. The new machine has cut cycle times for certain measurement and inspection routines from 2 hours using Arden’s traditional CMM, to a just a few minutes.

Established in 1980, Solihull-based Nasmyth Arden is currently enjoying a period of strong growth. The company machines sizeable aluminium aerospace components from billets, castings and forgings, and has seen current turnover reach £3.7 million. However, Arden expects this figure to reach £4 million by the end of the current financial year.

The reason for the company’s success is plain to see. This is a progressive manufacturing business that has invested heavily in its future. The manufacturing area, for instance, is dominated by a host of CNC machine tools, including two Mikron HP1350 five-axis machining centres. And now, the company’s inspection equipment can match-up following the installation of an OGP Smartscope CNC 800 multi-sensor measuring system.

Brains behind the brawn

Arden, which employs around 50 people, specialises in electronic and electrical control (EEC) cases that are designed to protect the ‘brains’ of an aircraft’s engine. These complex, prismatic machined parts feature hundreds of threaded inserts. As with almost all aerospace components, 100% inspection is an essential contract requirement. However, the job of checking for inserts proved laborious and was subject to human error.

“Put simply, we had to automate the process,” says Harjit Bhurjee, the man tasked with sourcing the necessary inspection equipment. “We approached a number of suppliers, but the only people who could get close to what we wanted were OGP. As soon as we saw what could be achieved using the Smartscope CNC, we signed on the dotted line.”

Smartscope CNC high specification shop floor measuring machines are designed to inspect components automatically, to the highest levels of accuracy, in the most hostile of environments. Multi-sensor deployment, including video, laser and touch probe, allows for unmanned inspection and high component throughput. The multi-sensor capabilities ensure that the CNC800 isn’t restrictive, but is capable of measuring any number of applications in the future.

Automate to accumulate

The OGP Smartscope CNC800 at Arden now undertakes the automated presence-checking of threaded inserts on all of the company’s large EEC cases, as well as inspecting for the unwanted presence of insert tangs. Furthermore, the machine performs extensive dimensional measurements. Previously, the company’s traditional CMM would have been used, but the time savings using the CNC800 were too good to ignore.

“There are many different features on the cases to be measured and these were taking 2 hours in some instances on our CMM,” says Mr Bhurjee. “Using the Smartscope CNC we can measure each side in just six minutes, without any detriment to accuracy. Our typical tolerances are ±0.1mm, but ±0.05mm is not uncommon.”

To confirm the company’s belief in its new Smartscope CNC, Arden conducted a gauge R&R study soon after installation. The study was performed to determine that the machine was capable of measuring in-process checks in line with the aero engine control systems standard, ES-31-603. A 1-off part was measured 25 times against a set of four features: flatness to within 0.08mm; seal groove width of 2.01/1.91mm; depth of face to seal groove of 1.40/1.50mm; and the true position of a tapped hole calculated from its X and Y position to within 0.2mm. The report summary status simply reads “pass”.

Life on quality street

Quality is clearly paramount at Nasmyth Arden, which prides itself on strict quality control over every aspect of its production system. The company maintains ISO9002 and AS9100 Rev C accreditations. It is also a member of the Midlands Aerospace Alliance and is an ADS SC21 Bronze award winner for the past three years.

Further impressing the company’s commitment to quality is its employment of apprentice inspectors, thus nurturing the next generation of talent. One such is second-year apprentice, Peter Stevenson, who is tasked with programming the Smartscope CNC800.

“I’ve had two sets of two-day training from OGP,” he says, “but to be honest, the Measure-X® metrology software is very simple to use. I can program a typical case for insert checking within 40 minutes, before walking away to do something else while it runs through its six- or seven-minute inspection cycle. The machine is also great for first-offs because I can measure while I program, whereas a CMM would need a CAD model. The OGP Smartscope has taken a lot of work from our CMM and more is set to follow.”

At present, Nasmyth Arden deploys its video sensor for all inspection, profile and feature measurement. Here, a high quality, 12:1 zoom lens calibrates itself at every magnification change for consistent measurement accuracy. Innovative solid state illumination sources, a colour camera and Measure-X® metrology software make every CNC model a powerful video measuring system. In terms of multi-sensor capability, Arden is currently deliberating the addition of a touch probe to further aid 3D dimensional measurement.