How can you improve a conventional remote-control toy car to make it faster, more efficient and more robust than similarly tuned "series-standard" vehicles in a head-to-head race? The Association of German Engineers (VDI) and Hannover University (HSH) - which jointly launched the JET challenge for tech-savvy youngsters back in 2007 - are asking exactly that. Much like full-scale motor racing today, the challenge goes beyond just cranking up the speed, with energy efficiency playing an equally important role. Visitors to IdeenExpo in June can see the results of this year's JET challenge live in action at the HSH stand, where 25 teams are pitting their 1:10 model racecars against each other on a 20-meter-long track. The rules are strict, with each team given a budget of just 50 euros to play with. Except for the battery, motor and speed controller, competitors have to buy, develop or build all components themselves.
With teams still busy preparing, the pupils from Eugen Reintjes vocational school have decided to upgrade their racecar with a hard-wearing, robust gear train. But since the tight budget pretty much rules out the option of designing a specialist solution, the students hunted high and low for an inexpensive alternative and finally came across the Cologne-based motion plastics specialist igus. Once the gearwheels had been successfully configured online, igus printed them using the selective laser sintering (SLS) technique and the high-performance plastic iglidur I6 - a material that is exceptionally strong. During a trial at the company's test laboratory, the engineers from igus ran gearwheels made of polyoxymethylene (POM) and iglidur I6 at 12 rpm under a load of 5 Nm. Although the milled POM gearwheel failed after just 621,000 revolutions, its printed iglidur I6 counterpart was still in tip-top condition after one million revolutions, meaning the team from Eugen Reintjes school don’t need to worry about breaking down. In fact, the gearwheels have already passed their first trial run, during which the team’s energy-efficient racecar reached a maximum speed of 60 km per hour.