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(...) Steve, One rotation sensor is allowed. There are also two light sensors, so your idea is definitely doable. The situations that are confusing are when the pull of the other robot prevents your robot from making any headway, as well as when (...) (18 years ago, 6-Jun-06, to lugnet.robotics)
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You only need one rotation sensor and some fancy gearing. Using a differential in a way similar to the "South Facing Cart" or the stearing drive in a dual differential setup, you could directly measure the amount of spin between a driven wheel and (...) (18 years ago, 6-Jun-06, to lugnet.robotics)
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(...) Ummm.... that's not the way I remember the mechanics. There is a torque created that is force on the drawbar times the drawbar height from ground. That torque will lift your front end. Doubling your own drawbar height halves your pulling (...) (18 years ago, 6-Jun-06, to lugnet.robotics)
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(...) Dean, Thank you for your response. I am going to get on with the tow rope suggestion right away. You might like to know that your 2002 'Building Lego Robots for FLL' guide was the first thing that I read. Raj (18 years ago, 6-Jun-06, to lugnet.robotics)
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(...) Raj, There's a bit of confusion here. I believe the above quote actually came from Steve Baker (posting only as Steve). As Steve Baker pointed out, there is a difference between kinetic (sliding) friction and static friction. ((URL) In the (...) (18 years ago, 6-Jun-06, to lugnet.robotics)
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(...) I don't think Dean was talking about torque from the rope tipping the robot; I think he was talking about the fact that a raised attachment point for the rope can result in a downward component of the tension, increasing the force down on the (...) (18 years ago, 6-Jun-06, to lugnet.robotics)
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(...) Sure, I understand the argument. But this old farm boy has both a few hours in the driver's seat of a farm tractor, as well as a couple of engineering degrees, both of which prompted my cautionary statements. Let me start by saying that I (...) (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) (Or vice-versa!) (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) Yeah - bad for a tractor with front-wheel steering - and a need to steer - not so bad for a robot with either no steering or rear-wheel skid steering. This robot really doesn't care if it's front end gets light - but for a tractor it's a major (...) (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) Thought provoking question. It led me to the conclusion that when the bot is generating it's maximum possible drawbar pull (as limited by the motor and drive train), the weight on the undriven front wheels (I'm assuming a rear wheel drive (...) (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) Steve Hassenplug, Sorry, my mistake. Thank you for the Wiki link and all your help. Raj. (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) Dave, Actually I am very happy and grateful. I am getting a crash course. Couldn't have asked for more. Raj. (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) That makes sense. (...) Yeah - I agree. So we have to sum some force vectors here. If our robot is pulling to the left, we have a horizontal 'drive' force to the left and a force in the tow rope going off to the right - plus a force due to (...) (18 years ago, 7-Jun-06, to lugnet.robotics)
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(...) I'm with you until we get here. Attaching at the front of a long nose feels like a bad idea. Any side force on the tow rope will tend to pull the robot off course, and once slightly off course the force only gets worse. In any case, a (...) (18 years ago, 7-Jun-06, to lugnet.robotics)
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