A formula for success

Pattern makers, Freeform Technology explain how it is extending its 5-axis machining capability to optimise the manufacture of composite patterns and moulds for the Formula 1 industry - and other industries too.
Fred Hutton and Simon Burchett, two former production engineers at Formula One team, Red Bull Racing, decided in 2008 to start their own CNC machine shop specialising in the manufacture of composite patterns and moulds.

Called Freeform Technology, the company chose Buckingham as its base in the heart of the UK's motorsport valley, and today supplies not only Red Bull Racing but other F1 teams as well, including Lotus, Mercedes GP, Williams, McLaren and Marussia.

The fifth and latest 5-axis machining centre to be installed at Freeform Technology's 6,000ft2 facility is a DMU65 monoBLOCK 5-axis universal machining centre from DMG/Mori Seiki. Since 2005, this machine tool supplier has been an Innovation Partner to Red Bull Racing in Milton Keynes, which is where Messrs Hutton and Burchett first became familiar with the quality and capabilities of the equipment.

Another DMG/Mori Seiki 5-axis machining centre, configured with a B-axis spindle head and rotary table, has been in use for a couple of years at Freeform Technology, but the three other machines on site are from an Italian firm that provides equipment for light machining within a large working envelope. They are ideal for surfacing epoxy tooling block (also called model or pattern board), which at Freeform Technology forms a majority of the tools produced. The patterns and moulds are used for manufacturing carbon fibre reinforced plastic body parts and other components on race cars, such as the engine cover and even the steering wheel.
Additionally, the subcontractor produces some components directly, such as laminate under-floor planks for race cars, aluminium parts used in wind tunnel tests, and a variety of jigs and fixtures.

Going flat out

High quality work combined with rapid turnaround times have cemented Freeform Technology's reputation in the motorsport industry and underpinned its rapid growth. First-hand experience of the sector has paid dividends. However, the company is now a victim of its own success, as it finds itself with 14 employees working flat out from December to March, but with spare capacity during the rest of the year, after the F1 race season.
This was the main reason for buying the latest 5-axis DMG/Mori Seiki machine. Unlike the Italian plant on site, the German-built machine has the power and rigidity to tackle any material including the toughest of alloys.

In addition to machining tooling block, aluminium mould tools can now be produced, allowing the subcontractor to widen its customer base.

Particular targets are the aerospace, marine and automotive sectors, for which parts within a nominal half metre cube can be produced to very tight tolerances on the DMU65 monoBLOCK.

“It is not our intention to move into the manufacture of end-use metal components at the moment, even though we could, but to concentrate on what we know best and transfer our expertise in composite pattern making across to other industries,” comments Fred Hutton. “We have already produced front and rear bumper patterns for the Nissan RML Juke-R and the BMW WRC Mini.

“We see automotive as a growth area for us, as more and more CFRP parts are being incorporated into road cars, or at least offered as options. We also intend to offer mould and pattern making services to companies in the aerospace supply chain.”

Machine capabilities

Programming of jobs generally starts with a customer’s IGES or STEP file which is imported into Freeform Technology’s Siemens NX8 CADCAM software for producing the toolpaths, some of which are very complex. Fully interpolative 5-axis scanning cycles on the DMU65 monoBLOCK produce fine surface finishes using mainly polycrystalline diamond (PCD) tooling from Cruing and ITC. The ball nose cutters in particular have proved effective, giving in excess of 10 times longer life compared with standard carbide.

The 18,000rpm HSK-A63 spindle option was selected to maximise productivity when machining aluminium and tooling block, the latter being cut dry. With a view to expanding into processing harder metals, an extra-large tank has been fitted to deliver through-tool coolant. Other options included are a 30-position tool magazine, Blum laser tool length measuring and breakage detection, and Renishaw spindle probing for setting workpiece datums.

Hutton likes the ± 120° swivelling trunnion design of the latest DMG/Mori Seiki machine, pointing out that in his opinion it is more versatile than a B-axis configuration, which is limited by its inability to achieve such a large negative angle.

The new machine’s compactness in the Z-axis also promotes efficient cutting cycles and reduces the risk of interference, although Freeform Technology uses Vericut simulation software in any case before running a new program. Mould and pattern tolerances are generally ± 0.1mm, but the DMU65 monoBLOCK routinely holds half that figure.

Standard data for the machine includes a compact, 7.5m2 footprint, 650mm diameter rotary table, 650 x 650 x 560mm linear travels and acceleration of 6m/s2 in each axis to 40m/min rapids. Control is by DMG ERGOline with 19” screen and 3D software running on a Heidenhain iTNC 530 platform.

www.dmgmoriseiki.com

www.freeformtechnology.co.uk