All this really accomplished was to smoke one of the Tricerabot's motors.
Click on a thumbnail sketch to see the full size picture.
DaVinci's Birthday is an event staged by Corvallis every year. This year a tug-of-war was arranged between several Kinetic Scultures and the Robot Wars folks Tricerabot. It was an uneven competition.
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Karen and I pose with Leonardo daVinci. Oh, all right. It's not the real Leonardo. That fellow has been dead for hundreds of years. But this Leonardo is standing for the real guy. I'm sure *he* would have been interested in what we are doing. |
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Tricerabot versus Mona Fly. The weight ratio was about 4 to one in favor of Mona Fly. Tricerabot got pulled like it weighed nothing while its wheels just spun. |
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In an attempt to weigh down Tricerabot, one of their team rides it. But Mona Fly still had about a 2 to one weight advantage. All this really accomplished was to smoke one of the Tricerabot's motors. |
Before the competition several people had predicted the KSRs would get creamed. This was based on the fact that the Tricerabot had about 20KW of [instantaneous] power in that box. That is a lot! In fact, that is about as much power as the average compact automobile uses driving on a flat freeway.
By contrast a KSR is human powered. Each pilot contributes about 1/8 horsepower. Roughly 100W per person. So Tricerabot has about 200 times as much power as Mona Fly. How could Tricerabot possibly lose? Well, it did. Obviously power isn't everything.
Mona Fly has two advantages: traction and torque. And, as it turns out, those are the two characteristics that are important in a tug-of-war. Power really doesn't matter. Mona Fly's huge mass gave her traction. And her extremely low gear ratio gave her torque.
Most, if not all KSRs have high mass and low gear ratio. So Tricerabot didn't have a chance against any of us. Unfortunately we were unable to prove this because of the smoked motor. Instead we decided to have KSR to KSR tug-of-wars. [We had an audience and The Show Must Go On.]
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Gorillas In The Rex has an extremely low gear. I figured we had the advantage of torque. But I hadn't considered the importance of traction when we went up against Mona Fly. To put on a show I decided to ride as a passenger and let Karen provide the power. We were pulled backwards with our tire skidding. |
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Realizing my mistake, I shifted my weight to the front bumper where it would do the most good to keep the wheels from sliding. That still wasn't enough, and our tire still skidded while we were pulled backwards. |
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The next match is Mona Fly against a KSR that is still under construction. I don't remember its name but it's something like Surf Mobile. It was easy to predict the outcome. Mona Fly was heavier and had lower gears. |
| Unfortunately Surf Mobile suffered some damage in the competition and taco'ed a wheel. |
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Having learned my lesson against Mona Fly, I decided to greatly increase our traction while competing against Maltese Fulcrum. We switched to off-road tires, with their greatly increased surface area. Both Karen and I pedalled. And I recruited three riders. That's Leonardo behind Karen. Bob Durst [of Mona Fly fame] is standing on the bumper. And a woman from the Tricerabots team is in the second passenger seat behind me. Malese Fulcrum has 8 pilots and weighs a ton, empty. I knew we had no chance to slide their tires. But I hoped we had more torque than they did. We never found out. We still didn't have enough traction. Maltese fulcrum was able to pull us backward. This in spite of the fact that our wheels were still turning to pull us forward. We had enough torque to keep fighting. We just didn't have the traction to fully use our torque. |
I am curious if we would have beaten Mona Fly if we had gone against her in this last configuration. We may never know.
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Copyright (C) C Allen Brown 2002.
