[archiver]

Posted by Ken Leung at 2/11/2001 5:21 AM EST


Student on team #192, Gunn Robotics Team, from Henry M. Gunn Senior High School.


In Reply to: WHEEL TRACTION--PLEASE RESPOND
Posted by Jason Wolf on 2/10/2001 12:24 PM EST:



Just a couple of things you want to look at.

As other people said before, you want to increase your area of contact with the carpet so that you can have a bigger possibility of maximizing your friction force from the wheel. Like another person said, you can lathe the wheels flat to have more contact area. But another way of doing it is to add more wheels, so that the chain will be driving two wheels on one side instead of two, which basically mean you have a wider wheel.

A second thing is to increase friction on your wheels. You can do a couple of ways. You can try cutting grooves into the wheels, either horizontally or some kind of pattern like tires. Or, you can order some timing belt and add them onto the wheel so that the nods on the timing belt will be pushing against the carpet. A third way I can think of is to use some screw and mount them along the wheel, so the screw head will be gripping onto the ground. But you have to be really careful about this: You want to make sure you are allowed to use screws in this function (instead of a fastener) or else you will have to buy them from small part. Make sure you are not damaging the carpet doing this, and you want to make sure the screws don't come off or else you will be leaving part of your robot on the field.

A third thing is to add more weight on the side of the wheel. After all frictional force depends on mass. You can either shift weights toward the wheel side, so that the over all weight are pushing more on the wheels instead of being supported by caster or something. And/Or you can just add more weight on the robot in a general place, depends on what kind of space and weight limit you have. But you want to watch out if your wheel axle can handle the weight stress.

The last thing is that, as Michael Martus said, you might want to have a slower drive train. Not necessary reducing the power output to the motor, but to physical gear down the speed of the drive train.