Robotics : 6958


Robotics / 6958	6957 \| 6959

Subject:	Re: a couple of new-bot questions from a generally quiet lurker
Newsgroups:	lugnet.robotics
Date:	Mon, 20 Sep 1999 08:22:50 GMT
Original-From:	dave madden <dhm@mersenne.+StopSpam+com>
Viewed:	543 times

=>From: "Stephen P. Gibbons" <steve@aztech.net> =>... =>My biggest gripe with this design [differtrans] is that there is no =>way to get all motors contributing to a single effort in one =>direction. Perhaps you could use two regular motors joined through another differential to provide drive, and a micro motor to provide turning? (I don't have a micro motor, so I don't know whether it's got enough torque to do any good. In addition, you'll probably waste a lot of power through all the gears you'd need to set this up.) I think the best idea I've heard for the differtrans is to build a regular, one-motor-per-wheel platform, but also drive the differtrans inputs from the wheel axles. Then, use a rotation sensor on the differtrans outputs to see whether the robot is turning due to different axle speeds. This is a win because you don't have to transmit any power through the (lossy) differtrans, you get both motors driving the robot, and you still know whether your robot is going straight. (I didn't think of this; somebody else on the list did. It was a while ago, but maybe you could find the message in the archives. Or maybe the originator will speak up and tell us how things worked out for that robot...) d.

Message has 3 Replies:

		Re: a couple of new-bot questions from a generally quiet lurker
(...) If you have even more differentials, you could set up the "turning" motor so that its power is split - one direction turns (this limits you to turning one way, but there are always sacrifices), and the other side adds to the forward drive (put (...) (25 years ago, 20-Sep-99, to lugnet.robotics)

		Re: a couple of new-bot questions from a generally quiet lurker
(...) I came up with this idea (I don't know if I were the first to do it, though). It worked really great with almost no loss, but there was one problem. The differential and the gearing introduces some backlash, especially if you use those eight (...) (25 years ago, 20-Sep-99, to lugnet.robotics)

		Re: a couple of new-bot questions from a generally quiet lurker
(...) I assume that was me; I posted a message with a link to an LDraw file of a robot I came up with that uses that design. I can't take all the credit for it, however: I was inspired by Simen Svale Skogsrud's web page on his Vector Rover using (...) (25 years ago, 21-Sep-99, to lugnet.robotics)

Message is in Reply To:

		Re: a couple of new-bot questions from a generally quiet lurker
=>From: aszy@worldnet.att.net (Al & Becky Szymanski) =>... =>1. What is the value of an Add Subtract differential? I have seen the pic's =>that folks have made and followes some of the discussion, but I don't =>really grok the value of one of the (...) (25 years ago, 20-Sep-99, to lugnet.robotics)

9 Messages in This Thread:

Entire Thread on One Page:: Nested: All | Brief | Compact | Dots
Linear: All | Brief | Compact
This Message and its Replies on One Page:: Nested: All | Brief | Compact | Dots
Linear: All | Brief | Compact

Custom Search