Maximum Pushing Force

[Ken Leung]

Originally Posted by mzitz2k

I have read much about the pushing force of certain drive trains. What is getting me is that I have heard a few individuals in the forums say that the maximum force/amount that a robot can push is its weight times its coefficient of friction. If this is true, why would teams concern themselves with gearboxes and shifting down to insane low gears.

Consider this:

What good does a drive train do if the wheels are slipping all the time?

If you have horrible traction on your drive train, such as using just skyway wheels without any treads on them, no matter how hard you gear your drive system, you will never push as much as you want.

At the year 2002, Beatty was one of the special case because they got really really good traction at their feet. Mean while, most of the other teams chose to lift up 180 lbs goals to add more weight on their robot so they can have more friction at their wheels. Great examples are team 60 and 45's robot that year.

Another thing to consider is this:

The lower the load on the motor, the less currect they draw. Sometimes you have to gear your motors such that they don't pop the circuit breakers all the time. That may involve gearing the drive train to a stronger torque then you need, but it is still necessary to ensure the health of the robot.

Some other times, people just didnt know the maximum amount of force they can push is the amount of their traction force, so they mistakenly gear their robot to really low torque and waste a lot of the speed they could've gotten from the motors. I know teams who choose to only use 2 drill motor because they realize their strongest pushing force is how much traction they have, and didn't think 2 more atwood motors are necessary.