Nakamura-Tome turning centre is 80% more productive

Andrew Dolan from ETG discusses the Nakamura machine with a Harris RCS team member

To help meet demand as business returns to pre-pandemic levels, Harris RCS Ltd recently acquired a Nakamura-Tome WT100F turning centre supplied by the Wellesbourne-based Engineering Technology Group (ETG).

Established in 1974, Harris RCS is a sub-contract manufacturer that specialises in the aviation, defence and electronics industries.

Graham Harris, Harris RCS managing director, said: “Primarily working in the aerospace industry, we were impacted by the pandemic, and we have had to ramp up our production with less staff. This has given us the impetus to invest in new technology and automation to meet the rapid upturn in demand. With several twin-spindle single turret machines and a twin-spindle twin-turret machine on the shopfloor, we needed to accelerate productivity further and reduce shopfloor processes by completing more jobs in ‘one-hit’ - the Nakamura-Tome WT100F has proven to be the perfect solution.”

Harris RCS already had a 20-year-old Nakamura, and its existing twin-spindle twin turret machine required considerable setting time, which made it better suited for longer production runs. The obvious solution was to replace the old Nakamura with a new machine that was capable of ‘one-hit’ machining of complex parts while providing fast changeovers for the machining of batches from 30 to 1,500-off. With 23 CNC machine tools on the shopfloor supplied by a variety of manufacturers, Harris RCS had no allegiance to a specific brand, but having a Nakamura that had run reliably and consistently for more than 20 years – the company was confident in the quality and reliability of the brand.

As the first machine purchase from ETG, the Nakamura WT100F was commissioned at the start of the year. It has rapidly made an impact on the machining of aerospace components such as valves, unions and fixtures for wings, fuel control systems and undercarriage. Machining everything from aluminium, stainless, Inconel, nickel alloys and other aerospace-grade materials, the Nakamura has increased productivity by upward of 80%.

Mr Harris continued: “We are running efficiently with one operator running two machines in many instances, but with the twin-spindle twin-turret on the WT100F, it is like having one operator running four machines as the Nakamura undertakes simultaneous machining on the main and sub-spindle to slash our cycle times. What is equally important is that we have been able to also significantly reduced our secondary operations.”

With two powerful 11/7.5kW spindle motors and capacity for up to 48 tool positions with driven tool flexibility with 7.1/2.2kW of power, the heavy-duty Nakamura WT100F delivers a powerful turning solution with unfathomable stability and rigidity. At Harris RCS, this stability is enabling the company to eliminate grinding operations in many instances.

Mr Harris added: “We have some components that were previously sent for finish grinding, which removed our 100% process control and extended our lead times. We have one particular job that has a tolerance band of +/-0.008mm, which was previously finish ground. The precision levels and surface finishes on the WT100F enables us to finish turn the parts and completely eliminate second-op grinding. We have also run these parts through SPC to check tolerances, and the repeatability of the Nakamura is excellent.”

Increasing throughput
The flexibility has reduced secondary operations throughout the facility with more parts coming off the Nakamura complete and ready to ship to customers. While this is making an impact on the shopfloor, the overall productivity level of the Nakamura is exceptional.

Mr Harris said: “The machine is 50 to 80% more productive than our other machines. This is a combination of the robust platform that enables heavy-duty machining as well as the simultaneous sub-spindle machining, which is effectively like having two machines running in one compact footprint.”

On one austenitic stainless steel part that is very difficult to machine, the Nakamura has revolutionised the process. Previously machined in one 2min operation with a subsequent 40sec operation, the Nakamura now completes the aerospace part in 1min 30sec. Furthermore, with an OD and ID bore tolerance tied together at +/-0.012mm – the parts required considerable setting-up time for the secondary operations. This labour-intensive task has been eradicated with the Nakamura.

Mr Harris is also extremely happy with the level of service offered by ETG. He said: “While we already knew the Nakamura brand is proven for its quality and reliability, we were not familiar with the ETG service as it was our first purchase from them. However, the service has been excellent – they really can’t do enough to help. We had one small teething issue with the control system and when the engineer quickly came out to resolve the problem, he asked if we needed any help with our new acquisition. He then spent the rest of his day working with our team on programming tricks and tips – nothing is too much trouble for them.”

As the Coventry manufacturer continues to ramp up production rates in line with the aero industry exiting the pandemic, Mr Harris added: “The pandemic has accelerated our plans to introduce new technology and automation into the business and the Nakamura WT100F is a perfect example of how we are adopting new technologies and methods to increase throughput, enhance the customer service experience and compress our lead-times. The Nakamura is also reducing the burden on our shop floor team, as they have fewer set-ups, and they can comfortably run the WT100F and other machines simultaneously.”

Mr Harris concluded: “We are delighted with the performance of the Nakamura WT100F and more importantly, the shopfloor guys love it too. When we make our next investment, it is sure to be another Nakamura machine from ETG.”