Ready to Test
Building motorcycles that can withstand the most grueling environments - and competing globally with some of the largest and richest manufacturing companies, are all in a day’s work for KTM. To maintain its lead, the winning builder of twowheeled off-road, high-performance and racing machines relies on prototype and production parts supplied by Proto Labs rapid injection moulding service.
Austria based KTM Sportmotorcycle AG builds just 110,000 motorcycles a year. By contrast, industry leader Honda usually pumps-out more than a million units every month, on average. So, how does a relatively small, niche builder like KTM compete in a market dominated by a Japanese manufacturing giant?
First and foremost, KTM produces only high performance bikes, which are, famously, ‘race-ready’ the moment they leave the factory. Motorsport is without question the toughest test of man and machine – it’s the quickest way to find a weakness in either. For many off-road races in certain categories, a typical starting grid consists largely of KTM bikes. Over the years, the company has accrued more than 130 world titles and is perhaps the best-known competitor in the annual Dakar Rally. A part-failure due to a material or design defect can have serious implications not just for the competitor, but also for the company and its hardwon reputation.
Helmut Gröbner is KTM group leader for plastic components, and heads-up a team of 10 designers. “The pressure on the product development team is enormous,” he says. "If a plastic part is approved for production it has to be 100% right. We leave nothing to chance. Our customers trust us implicitly.”
A new part is initially developed as a 3D CAD model in ProEngineer Wildfire and is immediately subjected to extensive static and dynamic finite element stress analysis. When the CAD design is finalised, the company uses Moldflow to simulate the injectionmoulding process, and only then can a prototype part be made for physical real-world testing.
In the case of KTM, ‘real-world’ is shorthand for conditions most people and most motorcycles would never encounter. But, KTM customers have very high expectations, and test-conditions for a new part need to be considerably worse than they are likely to come across.
No amount of virtual testing will guarantee a durable prototype. The only way to test the part is to make it and subject it to extremes of stress, temperature, load, etc. A prototype should be as close to the final production version as possible, both in terms of mechanical qualities and also material.
"Our first project with Proto Labs’ rapid injection moulding service was a cover for a silencer on the exhaust,” says Mr. Gröbner. “Our budget for tooling was only €25 - 30,000 and we couldn’t risk going straight to production with a new design.” Size of development budgets is also another way in which KTM differs to Honda and other big manufacturers.
“Time was also short, but a colleague remembered seeing an advertisement for Proto Labs. So, we gave it a go, took delivery of the prototype and in testing quickly discovered that the part we had designed in plastic wasn’t durable enough. Eventually, we decided to make the part from metal, but had we not made the prototype with the help of Proto Labs, we would have wasted a great deal of time and money and we may well have ended up with a sub-standard part on the bike.”
Using conventional additive-prototyping methods to create the test part would have been inappropriate. "We have a 3D printer in-house, but clearly, these parts wouldn’t have given us any useful information other than visual. Other prototype methods such as vacuum casting and machining from solid plastic are useful, but the process of inquiry, quotation and delivery would have taken much longer than using Proto Labs."
Happy with its first experience, KTM’s second opportunity to work with Proto Labs came soon after.
"We were optimising the design of a filter compartment cover, which had been previously made of metal,” says Mr. Gröbner. “The goal was to design a cover that would open quickly without the need for a tool, but would also provide secure closing, so that strong vibrations couldn’t loosen it. We already had ideas how we would make the part in plastic, but time was very short indeed and series production was imminent. We had to find a solution, quickly.“
“Happily, Proto Labs’ service came to our rescue again. We made our first part, which immediately showed up problems with the fit and the securing mechanism. We made some design revisions and the second part, everything was perfect. In just five weeks, we had tried two versions, finalised the design and taken delivery of 5,000 finished parts of production quality. Proto Labs even had sufficient material in stock, so there was no delay. Our production launch was flawless and the solution to the filter box cover was found to be perfect."
KTMs may be race ready, but most also have to be road ready, which means parts must meet high standards for TÜV certification. “We designed a new grab handle for pillion passengers. The fundamental question was whether to use plastic or metal, and if we did use plastic, would the part achieve the required strength. Of course TÜV tests only finished, production parts, which we were able to submit by making them with Proto Labs. The parts passed the rigorous tests and are now in full production."
The next challenge for Mr. Gröbner and his team came just a few months ahead of INTERMOT, Cologne, one of the most important trade shows on the motorcycle industry’s calendar.
“Just three months before the show, we set ourselves the task of creating our latest idea for a new rear-view mirror for the KTM 1190 Adventure, a full year ahead of schedule.”
As all bike enthusiasts know, a mirror is a prominent part on the machine, in direct line-of-sight of the rider. What’s more, the flagship KTM Adventure bike would attract a great deal of attention from customers, dealers and the world’s press. The new part would have to be flawless.
"Usually, you need a full year for a design process from concept to production,” says Mr. Gröbner, “including technical inspection. In this case, our tight deadline was only met because of Proto Labs. We designed and took delivery of parts that were inspected and passed by TÜV before being fitted to the bike at INTERMOT. Only a few eagle-eyed visitors to the booth noticed that the mirrors on the bike present and those shown in the photo on the promotional poster were different. Incredibly, we redesigned and made the new part quicker than the printer could produce an updated illustration.”