For machining pattern board, aluminium mould tools and components made from composite materials, Lentus Composites — based in Eynsham, near Witney in Oxfordshire — has installed a Sahos Dynamic five-axis bridge-type machining centre with a 5m X axis.

Built in the Czech Republic by Blue Ray, this machine was delivered and commissioned in March 2016 by sole UK agent Asquith Butler Ltd, Brighouse (www.asquithbutler.com).

Simon Odling, managing director of Lentus, said: “There are a number of high-speed machining centres on the market — mainly of European origin — that are directly applicable to production in the composites industry. We chose the Sahos Dynamic for a number of reasons.

In particular, we felt that the construction of the machine, when compared to its competitors, was an improvement on the industry norm, providing a stiffer and more-stable machining platform.

“We also specified direct measurement on all axes — including the five-axis head. This gives absolute feedback and minimises the time-consuming maintenance and down-time associated with aligning the axes, as well as providing significantly improved positional repeatability.

We talked with other Sahos machine owners in our sector and received positive feedback. The consensus was that, while this Czech manufacturer is not as well known in the UK as other brands, it is a rising star in the industry.”
Lentus is also developing fast.

Part of the Polar Technology Management Group, the company is located on Polar’s 16-acre site in Eynsham, which has planning permission to be developed into a large technology campus in the next few years.

Lentus, which was established in February 2014 by Polar partners Scott Roberts and Mike Dewhirst, is managed by Mr Odling and technical director Paul Lewis; it was formed to supply composite products for super-conducting magnets used in MRI scanners manufactured in the UK.

Olympic success

The following year, the firm achieved a £2.6 million turnover with 35 staff, and it more than doubled its turnover in 2016 through diversification into industrial, marine, aerospace and automotive applications.

Lentus regularly develops and makes new composite products for the motor-sport sector, from GT and World Rally to F1; it also makes parts for manufacturers of high-performance cars and electric vehicles. Part of last year’s success was down to winning a partnership contract with Cervélo to design, manufacture and test frames for bikes, ridden with great success in track events at the Rio Olympics.

The ultra-stiff laminated carbon-fibre frames were machined to close tolerances on the Sahos Dynamic. To improve the performance of the bikes further, Lentus designed and manufactured other weight-saving composite and metallic components.


The rationale behind buying the Sahos machine was to further develop Lentus’s ‘vertical integration’, as the ability to deliver complete supply-chain solutions — often in tight time-scales — was important.

The company already had two turn-mill lathes and a mill-turn machining centre with carbon management packages (all of which continue to be used), but a dedicated large-capacity machining facility was needed for composite components and the manufacture of patterns from tool board.

Lentus has grown rapidly, and machining is still split between in-house and sub-contract capacity; the in-house capacity on the Sahos machine is used for critical products and short-lead-time projects.

In 2017, a target industry for Lentus will be aerospace. The company’s directors have experience of this sector, and Lentus exhibited at the Farnborough Airshow 2016.

High-speed rotating-shaft components made from composites are another area of development for the company, and a major contract is imminent.

Machine details

The model chosen by Lentus from Blue Ray’s modular range of compact Sahos Dynamic travelling-gantry five-axis machining centres was the FC5000 High 5X.

It has a fixed 5m cast-iron table that allows either one long component to be processed or tandem machining, whereby a smaller part is set up at one end while the machining of another component is in progress at the other end.

A two-axis liquid-cooled head with a 24,000rev/min 12kW spindle motor provides the two rotary CNC axes (±110deg in A and ±400deg in C). Control is by a TNC530HSCI from Heidenhain, which also supplied the TS640 touch probe for workpiece datuming and the TT140 measuring probe for tool wear and breakage detection.

A 12-position disc-type magazine accommodates HSK-F63 tools. The machine at Lentus is currently operating a single shift, plus two or three hours unattended at the end of the day.

The addition of a second manned shift will be instigated soon, and 24hr operation with a 10pm to 6am ‘ghost shift’ is planned.

Background

Lentus designs, manufactures and ‘qualifies’ a broad range of composite products, using a range of manufacturing technologies that include autoclave/pre-preg, RTM (resin transfer moulding) and resin infusion.

The company is also expert in the filament winding of products such as hydraulic accumulators, pressure vessels, rings, tubes, sleeves and shafts. It gained ISO 9001:2008 quality management certification in September 2014 and is currently audited under a UKAS-accredited scheme by TUV.