5-axis star for composite materials

Built in the Czech Republic by Blue Ray, the 5-axis machine was delivered and commissioned in March 2016 by sole UK agent, Asquith Butler.

Simon Odling, managing director of Lentus comments: “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, more stable machining environment.

“In addition, we specified direct measurement in all axes including the 5-axis head. These provide absolute feedback and minimise time-consuming maintenance and downtime associated with aligning the axes, as well as providing significantly improved positional repeatability.

“Having tested the market with other local machine users, we received positive feedback from other Sahos owners in our sector. The consensus was that this Czech manufacturer is not as well known in the UK as other brands but is a rising star in the industry.”

Lentus is in ascendancy as well. Part of Polar Technology Management Group, it is located on Polar’s 16-acre site in Eynsham that has planning permission to be developed into a large technology campus within the next few years.

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

The following year, the firm achieved a £2.6 million turnover with 35 staff and has more than doubled the size of its business in 2016 through diversification into industrial, marine, aerospace and automotive applications. Lentus regularly develops and manufactures new composite products for the motorsport sector, from GT and World Rally to Formula 1, as well as for high performance car and electric vehicle producers.

Part of last year’s success was also 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 for the Sahos machine’s purchase was to further develop Lentus’ vertical integration, as the ability to deliver the complete supply chain solution, often in compressed timescales, was important.

There were already two turn-mill lathes and a mill-turn machining centre with a carbon management package on site, 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 boards.

Lentus has grown rapidly and machining is still split between in-house and subcontract capacity. Internal 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, underpinned by legacy experience of the directors in the sector and the company’s participation at the Farnborough Airshow 2016. High- speed rotating shaft components made from composites is one area of development and a major contract is imminent.

The model chosen by Lentus from Blue Ray’s compact, modular range of Sahos Dynamic travelling-gantry, 5-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 machining of another component is in progress at the other.

A 2-axis, liquid-cooled head, which carries a 24,000rpm/12kW spindle motor, provides the two rotary CNC axes, ±110° in A and ±400° in C. Control is by a TNC530HSCI from Heidenhain, whose TS640 touch probe for workpiece datuming and TT140 measuring probe for tool wear and breakage detection to minimise spindle downtime are also in use. A 12-position disc magazine is installed for HSK-F63 tools.

The machine is currently operating a single shift at Lentus plus two to three hours unattended at the end of the day. Addition of a second manned shift will be instigated soon and 24-hour operation with a 10pm to 6am ghost shift is planned.

Lentus designs, manufactures and qualifies a broad portfolio of composite products using a range of manufacturing technologies including autoclave/pre-preg, RTM (resin transfer moulding) and resin infusion as well as being experts in the field of filament winding of products such as hydraulic accumulators, pressure vessels, rings, tubes, sleeves and shafts.

ASQUITH BUTLER www.asquithbutler.com

LENTUS COMPOSITES www.lentuscomposites.co.uk