pic: Magnetic traction

[billbo911]

loading photo ...

[Bjenks548]

Nice mini bot idea

[roborat]

we were looking at the same ideal but with the wheels at an angle on the sides with something hanging below to keep it at the proper angle

[Chris is me]

Are you concerned that the magnet will take away from your wheel's traction? Or is the magnet not touching the pole- increasing the robot's downforce?

[548swimmer]

I'm not sure, but it seems like there's a minuscule gap between the magnet and the pole.

[Richard Wallace]

The steel pole is ferromagnetic, so a magnet will exert a pull toward it, aiding traction of the wheel(s).

Steel is also an electrical conductor, so electric potentials induced in it as a magnet moves will drive the flow of circulating current. Magnetic fields due to the circulating current will interact with those due to the magnet, developing a drag force that opposes the magnet's motion. So the steel pole acts as a brake on the magnet -- even if they don't touch.

[billbo911]

Originally Posted by Chris is me

Are you concerned that the magnet will take away from your wheel's traction? Or is the magnet not touching the pole- increasing the robot's downforce?

The plan right now is for the magnet to be held approximatly .1" off the surface of the pole. The calculations we have done so far show that we should have a force of approx. 20 Lbs of force pulling toward the pole.
Prototyping has yielded some interesting results, and some good insight as to what details we still need to address as well.

[billbo911]

Originally Posted by Richard

The steel pole is ferromagnetic, so a magnet will exert a pull toward it, aiding traction of the wheel(s).

Steel is also an electrical conductor, so electric potentials induced in it as a magnet moves will drive the flow of circulating current. Magnetic fields due to the circulating current will interact with those due to the magnet, developing a drag force that opposes the magnet's motion. So the steel pole acts as a brake on the magnet -- even if they don't touch.

The key will be to tune the position of the magnet to provide "just enough" traction, yet not too much apparent friction.

[RoboDesigners]

When I saw your picture/diagram, this was what came to mind...
http://www.vexforum.com/wiki/index.php/Magbot_Model_1