The term "run" in the heading is perhaps a little generous, as the Rennholz trike can only actually go up to a top speed of 15 mph (24 km/h) for about ten minutes before needing a battery swap. Literally translated as Race Wood, it's by no means the only example of a drill-powered vehicle but the gorgeous curves of its shaped wood frame and familiar trike form factor make it much more of an eye-pleaser than, say, the University of Louisiana's Cajun Crawler. It was planned, designed and built by a team of product design students from HAWK University of Applied Sciences and Arts at Hildesheim in Germany for last year's Cordless Screwdriver Race and although it didn't actually win, the design did take both the Jury and Public awards at the race.
Team members Jirka Wolff, Marcel Heise and Andreas Patsiaouras, with project support from Reiner Schneider, spent ten weeks of the spring 2011 semester planning, designing and building Rennholz for the Akkuschraubenrennen – or Cordless Drill race – organized by HAWK University. After fine-tuning the drive mechanism, steering and driving behavior of the vehicle on a test rig constructed from steel, work began to bend and shape the trike's curvy plywood frame, with technical and material support provided by wood shaping specialists Becker Brakel.
Rennholz features custom 16-inch rims at the front and a 20-inch rear wheel, all using Schwalbe Kojak tires, with a caliper brake providing stopping power at the rear.
The rules of the race state that entries must only get their power from a supplied Bosch PSR 18 LI-2 cordless drill/driver, which in the case of Rennholz is connected to the rear wheel. The race runs for four laps around a flat oval course, with drivers being allowed brief stops in the pit zone during the race to swap out the drill's battery as necessary.
Wolff told us that the vehicle managed to notch up the third-fastest round during qualifying and made it to the quarterfinals, but failed to secure a race win.
There are currently no plans to develop Rennholz further, but the vehicle is making a few public showings in Germany, most recently a design fair in Leipzig called Designers' Open 2011.
Sources: Rennholz, HAWK University of Applied Sciences and Arts
