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(...) It does happen - if you use more that 2 motors or if you try to use a RC motor. The driver circuit limits current around 500mA, and at that rate it is not long before going in thermal shutdown mode. (...) No, you won't see smoke... RCX motor (...) (19 years ago, 7-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help (diff sensor)
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Philo, That's interesting, and looks to explain why it is that I've never been able to observe the RCX output going to thermal or current protection cutoff? I've one largish sumo type bulldozer style robot with 4 treads that can easily push 4-5 (...) (19 years ago, 7-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help (diff sensor)
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(...) Actually it does - barely. With the increased current, RCX output voltage drops, so does motor stall current. See these compared charts: (2 URLs) Philo (19 years ago, 7-Jun-06, to lugnet.robotics, FTX)
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| | Re: Newbie needs Help
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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 (...) (19 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 (...) (19 years ago, 7-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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(...) (Or vice-versa!) (19 years ago, 7-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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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 (...) (19 years ago, 7-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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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 (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help (diff sensor)
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(...) Quite true. My bad. -dave (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help (diff sensor)
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(...) I think you need another pair of gears on one of the wheels to reverse its direction. If you are going to use a rotation sensor to measure the slippage then you need to realise that the sensor is notoriously poor at very low speeds. You'll at (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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