How can we drive on this new floor?

[PowerOfKings]

Originally Posted by vivek16

Look, all the ideas with fans:

Why not take your 200 pounds of force going downwards, point that to a side, and use it as a means of propulsion? It would certainly be a lot more efficient than using the force to increase the traction (it will still be low traction).

-Vivek

The 200 pounds of force comes from the fact that it is a vacuum creating pressure underneath the robot so in a 10x10 area with 1 psi (pound per square inch) you would have 100 pounds of force. You would not have nearly the same force from simply the fan on the side.

However we calculated that it would only take 7 pounds of force applied from the side to start a robot moving sliding sooo...

[Cyberphil]

Did anyone else see the size of that fan? Do you really think that would be worth buying 30 of those for a little bit more propulsion? Personally, I think its a waste of time, and how can we have tank treads if the rules state: "The ROVER WHEELS must be used in a “normal” orientation (i.e. with the tread of the wheel in contact with the ground, with the axis of rotation parallel to the ground and penetrating the wheel hub). No other forms of traction devices (wheels, tracks, legs, or other devices intended to provide traction) are permitted."

[JagWire]

Originally Posted by Cyberphil

Did anyone else see the size of that fan? Do you really think that would be worth buying 30 of those for a little bit more propulsion? Personally, I think its a waste of time, and how can we have tank treads if the rules state: "The ROVER WHEELS must be used in a “normal” orientation (i.e. with the tread of the wheel in contact with the ground, with the axis of rotation parallel to the ground and penetrating the wheel hub). No other forms of traction devices (wheels, tracks, legs, or other devices intended to provide traction) are permitted."

I think they were referring to what is called "tank drive" which you can think of like driving a bulldozer, only without the tracks, just the wheels. The wheels on one side would operate together independently from the other side.

[GregW11]

Originally Posted by johnr

Does this make any sense? Six wheeled bot. Four corner wheels driving forward and two side centered wheels driving backward as needed. Or, one wheel dead center of bot that would spin oppisite as needed. Then hand the whole thing over to programers. They can make it work.

I would guess this is roughly the setup you had in mind with wheels:

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(with possibly more series of sideways and forward-facing wheels)
Vertical wheels are forward facing, horizontal are sideways facing, in case people don't know.

And that wouldn't exactly be difficult to program, but the operators would have to have incredible coordination, since assuming you're driving in tank mode it would require three joysticks (two for each set of wheels, plus one more to operate the side wheels.) Add more motors if you want additional sets of wheels, unless you can put three wheels on one motor...

Either that or have the side wheels spin in conjunction to the outputs of the joysticks (i.e. if left is spinning full forward and right is spinning full backward, the wheels will turn in the direction that will provide the most traction. I'd have to run a simulation to determine exactly which would be the best way, whether you want more turning force, causing the trailer to possibly fishtail, or less to stabilize it.)
Again, not apparently difficult to program.

edit: (with random concerns I think of)
The only thing I could see right now is collisions of of the chains (if they're used to provide the moving force for the wheels) from the forward/sideways wheels. Seems it could be remedied by using varying radii with the grabbers on the wheels (spaced the name of them) that move the chain.

[Einstein]

WHEELS WHEELS AND MORE WHEELS. Not in line wheels but hub to hub to hub wheels. like a 16 to 20 wheel drive. all wheels drive all wheels have friction. You need as much surface on the ground as you can to get more friction. ie you have a car with the right inflation on all the tires you get the best gas per mile.
they always tell you to check you tire pressure. now let out 10 lbs what happens to you gas mileage (it goes down right) you did not change the weight of the car you just changed how much surface hit the ground which in turned gave you more friction. and that is what you need more surface to hit the ground. the weigh divided over the wheels don't matter the bot still stays the same weight

[sdcantrell56]

Originally Posted by Einstein

WHEELS WHEELS AND MORE WHEELS. Not in line wheels but hub to hub to hub wheels. like a 16 to 20 wheel drive. all wheels drive all wheels have friction. You need as much surface on the ground as you can to get more friction. ie you have a car with the right inflation on all the tires you get the best gas per mile.
they always tell you to check you tire pressure. now let out 10 lbs what happens to you gas mileage (it goes down right) you did not change the weight of the car you just changed how much surface hit the ground which in turned gave you more friction. and that is what you need more surface to hit the ground. the weigh divided over the wheels don't matter the bot still stays the same weight

Simply put, this is incorrect. The friction force is equal to the normal force times the coefficient of friction. This has already been discussed numerous times. Increasing surface area on an ideal surface will never increase the friction.

[BJT]

We found out a few interesting things today. we mounted 4 of the rover wheels on the back of our 2008 lowered center 6wd and drove it on the FRP. the weight is biased pretty far back so the front never touched down. right away you could push it around really easy like they did at the kickoff. after wearing out a few batteries driving around, the wheels got a a significant amount more traction. we then put a small scale in front of the front bumper and told the driver to push as hard as he could without spinning. it pushed with about 35 lbs of force until the wheels broke loose, when the scale went down to about 19 lbs.
This type of drivetrain (long 6wd, lowered center) drives like a smaller version of a wide robot as long as it stays on the rear 4 wheels turning was pretty easy but we haven't hooked up a trailer yet.

[jsasaki]

our team had an awesome idea!!!!!! we are gunna use a high speed fan to create traction because the fan will wanna stick to the regolith when air is being sucked in haha

[jsasaki]

1 more thing i forgot have an awesome 2009 and good luck

[sdcantrell56]

Originally Posted by jsasaki

our team had an awesome idea!!!!!! we are gunna use a high speed fan to create traction because the fan will wanna stick to the regolith when air is being sucked in haha

This has been deemed illegal by the GDC. Any method of increasing traction is illegal this year, which would include attempts at increasing your normal force.