How can you make turning smoother?

[jar24]

Originally Posted by dtengineering

Hey... one of the new Calgary teams! Welcome aboard, and welcome to Chief Delphi. I'm hoping to get out to Calgary this year, and look forward to seeing your machine.

We had this problem with our first robot, a four wheel drive machine... it worked great on our cement and linoleum floors at school, but when we finally got to Toronto and put it on carpet... we couldn't turn worth a darn.

The problem is inherent to skid steering... the front and rear of the robot needs to skid sideways, in order for the robot to turn. Since we design the robots to have high traction wheels (which were great for pushing) they were awful for turning. We had to reduce the coefficient of friction of one set of wheels so that they could slide sideways.

With a six or eight wheel drive (which we eventually switched to) the trick is to lower the centre wheels... this reduces the "normal force" (hey, physics in action) on the front and rear wheels, making it easier for them to skid sideways.

If you are locked into a four wheel drive design, you might want to consider some omni wheels... http://www.andymark.com/Omni-s/51.htm they also work great with six and eight wheel drive machines.

Good luck! Hope you get the machine running well soon.

Jason

Instead of the omni wheels from andymark I suggest you build your own, we learned the omni wheels they sell are kinda week if you get another robot pushing on you and your trying to maneuver out or away, My team has built our own omni and mecanum wheels for a few years now and they work just as good if not better and are a lot better on the teams wallet. Good luck, and hope to see you at worlds