This week River Raiders we found out there was an error with the results at the EV Challenge and Team SKM beaten our time in the first race in the second race. Well done to Team SKM and unfortunate that you did not get the recognition on the day.
River Raiders Win
Rod, Jamie and Wayne win the open (C class) race and Yuassa class in Roadbot 3 to take the 2012 ITC Global EV Challenge trophy.
Roadbot 3 was consistently the fastest car on the track, even lapping it’s stablemate Roadbot 4. Roadbot 3 had a big efficiency advantage over the 4 wheel car so we could travel a lot faster for the average 10 amp power we were targeting. In the end Roadbot 3 had used only about 80% of its battery capacity, so we could have pushed a lot harder.
Does this prove 4 wheel cars are less efficient than 3 wheel cars? While the cars had identical bodies, batteries, motor and controllers, we feel that there were some drive train losses in the Roadbot 4 that could be eliminated and we could increase the efficiency to get a lot closer to Roadbot 3, although with the extra wind and tyre drag of the fourth wheel and the extra weight of the fourth wheel, axels and diff, it will never be as efficient. On a tight circuit the improved handling cornering might be able to make up for reduced efficiency, but for efficiency races, the question is…. ”Confirmed”
River Raiders cars to be named Roadbot 3 (three wheels) and Roadbot 4 (4 wheels) for the 2012 EV Challenge
Picture: Roadbot Logo
The cars are finally running with most of the gremlins fixed, so today we spent some time playing around with gear ratios. It would be handy if we had a quick way to swap cogs, but alas we are getting good at taking wheels off and rebuilding clusters.
Started off with heaps of pickup and felt great on the carpark which is a bit tighter but a run with a pace car on a long straight road only clocked 40km/h. Back to the shed change ratios and we are getting less acceleration but still pulling fine and the top end seems like it will go a lot faster. Unfortunately didn’t get a chance to go back out and measure the changes - a job for next weekend.
Solution to the braking problems found - brake lever with twin cables and balance inside.
Video with 1 note
Test driving the new car for the first time. Brakes fail at the end of the video but no damage fortunately and easily fixed with improved clamp design in the brake balance bok
A hoot on the gravel, the cyclone motor has enough power to get the skinny bike wheels sliding around corners. The first test didn’t last long before the brakes failed, fortunately an easy fix with one of the cables slipping in the balance box.
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