To cope with the different demands of machining composite materials, both machines were significantly modified and supplied with integrated extraction systems, as well as fully enclosed and sealed working areas. The machines have been installed in the team’s expanding composites department at its headquarters in Enstone, Oxfordshire.
Both machines were acquired, initially, to machine the precision patterns (made from epoxy resin tooling board) that are used to make moulds for CFRP body parts. However, owing to the machines’ versatility and performance, the HPM 1350Us are now also being used to produce carbon inserts and Rohacell foam (used as a structural filler to strengthen CFRP parts), as well as a range of jigs and fixtures.
The decision to invest in the two Mikron HPM 1350U machines was made due to the inability of existing equipment to meet increasingly stringent part accuracy requirements in the composites department.
Explains Renault F1 Team’s composites manager Keith Dunsby: “We are committed to continuous improvement and always strive for excellence, so when it became apparent that two of our machines were not able to meet the accuracy and repeatability requirements demanded by our design engineers, we acted quickly to rectify the situation.
“Since being installed, the machines have been working around the clock, during the day, throughout the night and at weekends, and haven’t missed a beat,” he adds. From struggling to hit 0.5 mm positional accuracies previously, we are now achieving 0.1 mm or better.”
The working envelope of the HPM 1350U machines (1,350 by 1,150 by 700 mm) enables Renault F1 Team to machine a majority (up to 60%) of these parts. For larger components, like the car chassis itself or a rear crash structure, the team relies on gantry-type machines with a 4 x 3 m working area.
Renault F1 Team has a long-established technical partnership agreement with GF Machining Solutions. The partnership has been instrumental in the team investing, over recent years, in a number of AgieCharmilles wire and die-sink EDM machines, and Mikron 5-axis machining centres.
To address the accuracy issues being experienced in the composites department it was therefore natural that Renault F1 Team first approached GF Machining Solutions.
Explains Richard Ferguson, Renault F1 Team’s composites supervisor: “This was, to all intents and purposes, a different requirement in that previously, the Mikron machines acquired were for machining metal components. We explained the current issues and our requirements to GF Machining Solutions and they recommended the HPM 1350U machines for their size, power, versatility and performance, but with a number of significant modifications to make them more suitable for machining composite parts.”
These modifications included the integration of a high-efficiency extraction system installed on the machines’ tables.
“Machining carbon-fibre composites and Rohacell foam essentially creates a significant amount of dust,” says Ferguson. “This dust needs to be removed quickly and safely from the interior of the machine, and the wider machining area and environment. Positioning the extraction units on the machines’ tables delivered an effective and optimal solution.”
Modifications to the HPM 1350U machines also included the removal of the machines’ swarf conveyors, enclosing the Y axes and providing additional guarding to prevent dust ingress and escape. A final modification on both machines was the inclusion and integration of the more advanced Renishaw RMP600, a compact workpiece probing system featuring radio signal transmission which, working in conjunction with Renault F1 Team’s MSP software, ensures improved process reliability, faster and more accurate set-ups, and reduced scrap.
Says Dunsby: “The customisation of the HPM 1350 machines demonstrates the power of the positive partnership and the way in which specific needs can be quickly addressed and solved through collaboration, and by thinking outside the box.
“The HPM 1350Us are reliable high-performance machines,” he continues. “They are equipped with high-torque spindles that enable us to ramp up feed rates and achieve big depths of cut, which has helped us improve productivity levels, reduce part cycle times and meet tight lead times.
“In addition, the configuration means complex and intricate parts can be machined in fewer set-ups using 3+2 or full simultaneous 5-axis machining operations. Although initially acquired to machine bodywork patterns, the machines are now being used to produce a wide range and variety of parts, which has resulted in a faster ROI than was originally imagined.”