Kern Micro Vario five-axis machining centreTo combat the skills shortage in the manufacturing industry, Wilford-based
WLR Precision Engineering Ltd recently made the decision to automate its high-precision production while maintaining the skill levels of its highly qualified team of engineers. To increase throughput, precision, quality and consistency, the sub-contractor approached Cheshire-based
Rainford Precision Machines Ltd to acquire a Kern Micro Vario five-axis machining centre with an Erowa Compact 80 automated pallet-loading system.
Established in 1969 and located just south of Nottingham, WLR undertakes everything from prototype work to small- and medium-size batches for a variety of customers, including those operating in the oil exploration, medical and pharmaceutical sectors. As a company ‘dedicated to precision’, the ISO: 9001:2015 certified manufacturer is already an existing Kern user, reaping the rewards of unparalleled precision and performance. The automated Kern Micro Vario represents the sub-contractor’s second Kern machine purchase — in 2013, WLR installed a Pyramid Nano machining centre.
Discussing why WLR invested in a second Kern machine, WLR’s managing director Kevin Callon said: “One of my regrets was not having some form of automation on the Pyramid Nano when we first bought it, despite having the option. There was no way we would have bought another Kern without some form of automated loading to maximise the running hours of the machine.”
With an 80-component Erowa pallet-loading system and a 90-position automatic tool change, the Kern Micro Vario was the perfect solution. Installed in September 2022, the introduction of the automated Micro Vario now enables WLR to run production continuously ‘lights-out’ while using the existing Pyramid Nano for smaller batch runs and one-offs during daytime working hours.
Mr Callon explained: “The consistency of the components produced on the newer Kern is amazing and repeatable down to the micron level. The precision is so impeccable that we channel as much work as possible through the Kern Micro Vario. It is not only doing the really demanding high-accuracy work that it was purchased for but also undertaking the less demanding work that would normally be done on less precise machining centres.”
With incredible accuracy and repeatability, the engineering team’s demand to constantly check that workpieces are within tolerance and conform to requirements is reduced, alleviating pressure on the inspection team.
The Kern Micro Vario precision and repeatability is built upon the foundations of its thermally stable ultra-high-performance concrete (UHPC) base and internal temperature management system that combine with unrivalled kinematics and sophisticated design to yield precision and repeatability of <1.5µm and <1µm respectively.
From a specification perspective, the Kern Micro Vario has a compact X-, Y-, and Z-axis work envelope of 350 x 220 x 250mm, a -110deg to +110deg swivelling B-axis, and a 360deg continuous C axis. Furthermore, the tool changeover is less than 3sec, and the chip-to-chip time is 4.5sec – all feeding a high-speed 42,000rev/min HSK 40 spindle. Incorporating a Heidenhain TNC640 CNC control, 30m/min rapid rates and acceleration of 10m/s
2, the Micro Vario demonstrates astounding flexibility, speed and precision in a compact floor area.
Highlighting what distinguishes the Kern from other machine tools the company uses, Mr Callon said: “It is definitely the accuracy and repeatability, as well as a significant improvement in surface finishes. The Kern truly excels, particularly with harder materials, and this excellence isn’t solely due to spindle concentricity but rather the entire package. It is a very robust machine engineered to deliver remarkable repeatability.”
He added: “Previously, we didn’t have enough of the right kind of work for the Kern to keep it fully occupied, so we began assigning other tasks to the machine to fully utilise its capacity. We now appreciate the advantages of this approach, given its repeatability — the tolerances we find difficult to maintain on other machines are effortlessly attained on the Kern.”
With machine utilisation down to a ‘fine art’ and the variation in size and complexity of components in the workpiece loader honed to perfection, the sub-contractor is maximising the capabilities of the Kern. Mr Cullen explained: “The cost benefits are considerable as we never scrap anything. When we run the machine unmanned through the night, we know that everything will be spot on when we come in the next day.”
Even among the impressive range of CNC machine tools at WLR, the Kern Micro Vario was a complete game-changer regarding repeatability and consistent part quality. In these demanding times, the ability to produce consistently high quality parts is key to ensuring complete customer satisfaction.
Mr Cullan concluded: “Based on cost per part, the machine more than pays for itself. It completes jobs in ‘one hit’, faster and easier than our other machines, and to tighter tolerances. As we have such robust processes in place, it has generally reduced the burden on the inspection department and the workforce. It has also improved planning and lead times because parts come off the machine ‘right first time’. Overall, the Kern Kern Micro Vario five-axis machining centre is a great asset to our business.”