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(...) What I'm saying is that if the robot is moving along at (say) 3 inches per second - then the drive wheels will get most traction if they are turning at a speed equivelent to 3 inches per second. If they are rotating faster than that (because (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help (diff sensor)
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Some varied thoughts here: (...) I might be wrong, but my understanding of the Lego differential gearing is that if both shafts are turning at the same rate and direction, the outer gear/shell will turn at the same rate as the axles. Only when the (...) (19 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 (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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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 (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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(...) One rotation sensor and a differential will allow you to compare the rotation of two wheels. If the driven wheel and the undriven wheel come in the two sides of the differential, and the rotation sensor is connected to the drive ring, then the (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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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 (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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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 (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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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 (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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(...) Steve, Provided that my robot doesn't tip-over and that only the front wheels are driven. I have seen a video of a robot in last year's competition that opened up into a V-shape. The angle between the arms of the V being greater than 90 (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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| | Re: Newbie needs Help
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(...) Steve, Philo's page on 'Wheels, Tyres & Traction' seems to imply that increased speed will not make much of a difference or am I reading that wrong? By 'mechanically connect' do you mean by using two differentials? The maximum 'safe' gearing (...) (19 years ago, 6-Jun-06, to lugnet.robotics)
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