| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) (Or vice-versa!) (18 years ago, 7-Jun-06, to lugnet.robotics)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|
|
| | Re: Newbie needs Help
|
|
(...) 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)
|