pic: Team 2980 Open Source Robot

[Justin m]

Actual post below, sorry

[Jeffy]

Originally Posted by Justin m

Actually, our team discovered that when driving at the corner, the angle of the bars relative to the robot is slightly larger than 90 degrees

Is this a joke?

If not,
The angle compared to the direction of gravity is the defining factor for friction via normal force.

If so, you got me.

[Nuttyman54]

Originally Posted by Jeffy

Is this a joke?

If not,
The angle compared to the direction of gravity is the defining factor for friction via normal force.

If so, you got me.

I believe he's not talking about friction, but about the vertex that sticks out at each rung level. He is correct that those vertices (which is 90 degrees projected in the ground plane) is larger than 90 degrees in the the plane normal to the corner poles.

That being said, I don't think this design relies on the corners being 90 degrees, they simply chose 90 as their angle between the climbing wheels. They should roll over the vertices regardless.

[eedoga]

So...we decided to go with magnets. We found 110 lb electromagnets on the interwebs, and the current plan is to use three of them to hold the robot down onto the pole. This should create enough "normal force" to allow the wheels to drive up the pole. the current design uses three electromagnets. two at either end, and one in the middle on Nylon straps that are just short of the pole. The magnets would then pull the robot down compressing the springs slightly. As the robot drives and reaches the cross beams the electromagent would be turned off allowing it to pass over the cross beam. with the other two magnets holding the robot down. the magnet would then be reactivated on the other side.

My current concerns...
- The battery getting hot from running the electromagnets.
- Adding three spike relays to our current cramped electronics board
- Having the magnets stick to things other than the pole
- Electrical issues stemming from having such powerful magnets in close proximity to everything else...
- the rules on electromagnets which I haven't looked up yet myself, but the team seams to think are A-OK...

Edoga