In all forms of motor-sport, the power-to-weight ratio is crucial to maximising performance, with even the smallest improvements often separating winning from coming second. In powerboat racing Team WNT F2 is continually striving to improve the performance of its craft.

As part of its sponsorship of the team, WNT (UK) Ltd (www.wnt.com) is making its technical centre in Sheffield available for the production of a range of components that will help to reduce the craft’s weight and improve its overall performance. WNT project sales engineer Tony Gale has been providing the expertise required to develop parts and introduce new materials and tooling technology to the development process.

The most recent example was to replace the transom bolts with new versions made from Grade 5 (Ti6Al4V) titanium. Often found in aerospace airframe, marine, offshore, power generation and engine components, this material is both lighter and stronger than steel. The transom bolts hold the 230hp V6 two-stroke engine to the hull, allowing speeds up to 200kph to be achieved. There are six transom bolts in total.

By a combination of re-design and the use of titanium the team has removed 600gm from the craft’s overall weight (this is in addition to other significant weight reductions that Team WNT F2 achieved before the current season started).

The team’s driver Steve Hoult said: “Weight reduction is one of several things that we can control. Being able to call on WNT (UK) for assistance in this area was a great help in winning the championship last year, and it will continue to play an important role as we challenge for honors again this season. The fact that the company can put its latest cutting tools to the test to produce items such as the titanium transom bolts is a distinct advantage.”

The replacement bolts were machined by Mr Gale at WNT’s technical centre, using a selection of standard tools aimed at titanium machining. “There are two styles of bolt; one is 90mm long, the other 110mm long. Both require a mix of turning, threading, drilling and milling, which allowed us to make use of a variety of tools and apply cutting data directly from the information in our standard catalogue.”

The mix of tools included a 6mm-diameter solid-carbide drill running at 35m/min and a feed rate of 0.08mm/rev. The hexagon flats were machined using an 8mm-diameter end mill with a 1mm radius. This came from WNT’s Mastertool range and was run at 80m/min and 0.04mm/tooth feed. The main turning was undertaken using a WNT DNMG 150608
M34 HCN 5110 insert running at 80m/min and 0.25mm/rev feed, with the thread generated using a 1.5mm-pitch threading insert taking seven passes (and one relief pass) at 40m/min surface speed. The final operations of boring
the relief in the head of the bolt and drilling the holes for the retaining wire were undertaken using WNT’s solid-carbide Eco-Cut Mini boring bar and a 1mm-diameter HSS Uni Drill.

Tony Pennington, managing director of WNT (UK), said: “This work that we are doing to assist Team WNT F2 is an ideal way of highlighting the broad range of tooling available from WNT for a diverse set of applications. It also emphasises the level of technical applications support that we can offer through the WNT Technical Centre in Sheffield, where we are happy to work with customers to develop optimum machining solutions.”