Selecting the right gear at Nova Racing

Leamgington Spa-based Mills CNC, the exclusive distributor of DN Solutions’ and Zayer machine tools in the UK and Ireland, has recently supplied leading motorcycle transmission and gearbox design and manufacturing specialist, Nova Racing Transmissions Ltd, with a new, high-performance DN Solutions’ lathe.

The new lathe’s arrival has significantly strengthened the company’s in-house turning capacity and capabilities, helping reduce production bottlenecks and improve process efficiencies. The machine, a compact, Fanuc-controlled 8in chuck Lynx 2100LMB, was installed at the company’s manufacturing facility in Partridge Green, West Sussex in December 2024 and has replaced an older Daewoo lathe that, although still working satisfactorily, was slow and cumbersome to use.

Since being installed the new Lynx 2100LMB, equipped with driven tooling capabilities, has been put through its paces machining a range of high-precision motorcycle ‘close ratio’ gearbox components such as input and output shafts, gear blanks, dog rings and collars, in small batches for a diverse range of domestic and international end user customers.

Customers include teams and riders competing in the British Superbike (BSB), World Superbike (WSBK), Isle of Man TT and Motocross championships, as well as for motorcycle OEMs, motorbike racing clubs and individual motor cycle owners, enthusiasts and engine builders.

Components are also made for stock enabling the company to quickly supply customers with spare and replacement parts. Batch sizes machined on the Lynx 2100LMB vary from one-and two-offs through to 10-offs, and can also include prototypes and pre-production parts.

Specific parts machined on the Lynx 2100LMB include input and output shafts — essential components for every motorcycle’s transmission systems which are made from a tough and durable case hardening motorsport steel alloy supplied to Nova Racing in pre-cut rough bar stock from high-performance steel specialist, Bohler Steels.

Following machine set up, soft turning operations undertaken on the Lynx 2100LMB start by first reducing the diameter and length of each pre-cut bar. With 50mm dia bars, for example, typically 1mm is taken off the OD and 3mm off the length (1.5mm from each end). Other operations, prior to heat treatment, include gun drilling on each shaft’s centre line using high-pressure coolant to create a long narrow through bore hole with a high depth-to-diamater ratio.

There can be up to six soft turning operations, such as drilling and thread turning, performed on each shaft before heat treatment. Cycle times are short — up to 2-3min — and accuracies vary, according to each turned feature, and are typically +/-0.1mm. Tighter tolerances down to 10µm are required in hard turning operations.

Production bottleneck
Daniel Vaughan, engineer at Nova Racing Transmissions, said: “Prior to acquiring the new Lynx 2100LMB, gun drilling operations on gear shafts were all performed on one of our older Lynx lathes, a long bed Lynx 220LMA, acquired in 2014. During very busy periods, the over reliance on just one machine to perform such a critical machining process is not ideal and previously created production bottlenecks that were adversely affecting efficiencies and our ability to meet customers’ lead times.

“As intended, the investment in a new long-bed Lynx 2100LMB has provided us with additional turning capacity, enabling us to eliminate this specific production pinch point, enabling us to become more productive and efficient as a consequence.”

The interconnectedness and interdependency of Nova Racing’s complementary machining and manufacturing processes means that there really cannot be a ‘weak link’ in the company’s production chain. In the case of the gear shafts mentioned above, once gun drilling operations have been completed, the shafts are then moved to Nova Racing’s hobbing machines where a series of high-precision splines are machined on each shaft’s external OD surface.

Once finished, and deburring operations have been performed, the machined shafts are then sent out in batches for heat treatment at an external supplier, before being returned to Nova Racing for ‘hard’ finish turning operations performed on the Lynx 2100LMB.

Mr Vaughan said: “Production scheduling can be a challenge at the best of times. There are lots of moving parts, and there needs to be some flexibility built into our processes to cope with unexpected, last minute and priority jobs. If components are waiting in limbo for a lathe, machining centre, hobbing machine or gear cutting machine to become available, or for heat treatment processes to be completed, the efficiency of our whole operation is affected.”

Need to invest
Since 2012, which coincided with the company relocating to its current facility, Nova Racing has relied on DN Solutions’ (previously Doosan) Lynx lathes from Mills CNC for its small turned-part processing requirements. So, when Nova Racing, a company committed to continuous improvement, identified the need to invest in a new compact lathe back in 2024, it was not surprising that Mills CNC was one the first machine tool suppliers approached.

Mr Vaughan explained: “We have developed good relationships with Mills CNC over the years. Our previously acquired Lynx lathes are fast, powerful, precise and flexible. They are reliable and competitively priced, and the pre- and after-sales service and support we receive from Mills CNC cannot be faulted.”

Although Nova Racing approached three machine tool suppliers to provide quotes for the new lathe, the decision was made to go with Mills CNC resulting in an order being placed for a Lynx 2100LMB — a long-bed lathe with live tooling. The Lynx 2100LMB is a popular and proven compact lathe, ideal for fast and accurate small-parts processing. The machine has a rigid design and build and, despite its small footprint, provides customers with a 300mm maximum turning diameter and a 290mm maximum turning length.

In addition to being equipped with a 15kW 5,000rev/min spindle, a 12-station, servo-driven BMT45 turret, roller-type LM guideways, a tailstock and 3.7kW 6,000rev/min driven tooling capabilities, the Lynx 2100LMB supplied to Nova Racing also features an advanced Fanuc iPlus control with 15in touchscreen iHMI, a MH500 swarf conveyor system, 20bar through-spindle coolant capability and an automatic toolsetter.

Nova Racing, with its nine members of staff, operates like a well-oiled machine. The smooth running of the company’s production operation relies on access to advanced, flexible and high-performance machine tool technologies.

Quick set ups, highly accurate cutting and fast processing speeds are all of paramount importance, and is why the company continues to invest in Lynx lathes, backed by Mills CNC’s after-sales service and support (finance, training, servicing, and parts), for its small turned part requirements.