A market-leader in gearbox and transmission systems for the motor-sport industry is branching out into electric-vehicle transmissions and says that it has benefitted from a new production engineering manager — Dominic Prinsloo — driving its CAM software use up a gear.

Maidenhead-based Hewland Engineering (www.hewland.com) has a long history of being the ‘go to’ company to provide gearboxes for vehicles in competitions such as Formula One, LeMans GT, WRC Rally, ‘open wheel’ formula, and Touring Cars — plus high-performance sports cars that are equally at home on the road or track.

The company also produces transmission systems for Formula E electric cars — and it is currently working on a number of projects for electric road cars.

Hewland’s core business comprises gear components, including the box, gears and layshafts — in fact, everything that makes up the entire transmission system.

Around 95% of the parts are programmed using Edgecam software (www.edgecam.com), and almost all are complex, with tight tolerances in the order of 5-10µm.

Since joining Hewland in September 2017, Mr Prinsloo has introduced new ways of working with Edgecam. He said: “Hewland has used Edgecam for many years, but it was not realising the full potential of the software,” adding that introducing new methods has “led to astonishing results in reducing machining times and tooling costs.”

For example, the cycle time on a gearbox selector fork was cut from 65min to just 38min; and when tooling costs were also taken into consideration, the savings on that component were “considerable”.

With a larger fork, Mr Prinsloo’s methods with Edgecam saved 30min on each individual item; and forecasts show that the Edgecam changes will also lead to considerable savings on every type of gearbox fork they manufacture over a 12-month period.

Those changes include bringing in solid models for programming and generating the features from the model.

Mr Prinsloo said: “We also use profile features, either generated from the Features Find function in Edgecam or generated manually. When I came to Hewland, the practice was to input the values manually, which was time-consuming and prone to error.

"Now, code is generated by associating the tool-paths to the features, so whenever the component is upgraded to the next version and the model is manipulated — such as a particular diameter being changed from 32mm to 45mm — we just regenerate the feature and the tool-path changes automatically.”

Roughing strategy

However, Mr Prinsloo says the biggest ‘game changer’ was introducing Edgecam’s Waveform roughing strategy to Hewland, for both its milling and turning cells. “It is now used for all our face grooves, groove turning and ‘full rad’ inserts — reducing cycle times dramatically.”

Previously, when milling a range of gear-selector forks, a high-feed method was used, with multiple face cutters for one component. “Those step cutters only lasted for three parts before having to be replaced.

"We changed the manufacturing process to incorporate the Waveform strategy, machining at 2.8m/min at 4,200rev/min with a 10% step-over. As a result, we have reduced the cycle time by 20min on stage-one machining and 8.5min on stage-two machining — and we cut around 23 billets per cutter instead of three.”

Many of Hewland’s machinists admit to having been a little wary of Edgecam’s Waveform strategy at first, worrying that the ramped up feeds and speeds would break the cutting tools. “They had never seen anything like it before.

“I introduced it slowly, starting with low feeds and speeds then gradually increasing them until we got to the 10% step-over and 2.2m/min feed.

That was on EN 36 case-hardening steel, so the team very quickly appreciated what Waveform could do; indeed, they now want Waveform to be the default machining strategy.

“We have what we call legacy components that were programmed a long time ago. The team is asking us to change the programming to Waveform, saying they find it more reliable, and that it reduces load on the spindle and wear on the tool.”

Mr Prinsloo says Edgecam is going to be of increasing importance in future, particularly for prototyping new gear components for electric vehicles.

Design engineer Ashley Craig, who is currently working on a number of transmission systems for that market, said: “I liaise closely with Mr Prinsloo to ensure that the finished 3-D model can be accurately machined.

"It gives me total confidence that my designs will be faithfully translated into the finished part, and it ensures that Hewland continues to compete at the top level in terms of the gears and transmissions that we produce.

"Thanks to Edgecam, we can give our customers competitive prices, because it keeps both development and manufacturing costs to a minimum.”