Soccer robot help

For a school design project, I am supposed to design an RC soccer playing robot that can drive, and pick up and shoot ping pong balls at a goal wall.

The material is given, and includes:

  • 2 dc motors
  • sheet metal
  • various shafts, tubing, wiring, etc
  • various gears and pulleys
  • plastic and foam sheets
  • springs

My main question, what would be the best/most efficient way to use only 2 motors to drive, steer, pick up and shoot?

My group and I are all pretty new to robotics/mechanics so any help or advice would be greatly appreciated!




Is the 13 in your username your age? I think it’s going to be really difficult to do what you’re asking for with just two motors. You need two motors just to be able to move around, so you might have to settle for just pushing the balls around instead of picking them up and shooting them.

- Jan

No, I’m a second year engineering student. I guess steering is not a necessity, since the goal is to pick up balls from a pile on the ground, move up to a “goal line” and launch them at different holes in a wall. Everything happens pretty much in a straight line, but is there a way to drive and steer with a single motor?

Also, do you think some kind of rotating paddle/shovel system would work for launching? Like, maybe i would be able to scoop up the balls and fire them in one single motion

You can’t really do much driving and steering with just one motor. You can make something like the really cheap RC cars that go forward straight and turn when they back up, but that’s going to be difficult to control. Making the single motor scooper/shooter shouldn’t be as fundamentally difficult as long as you don’t need to control the two functions separately.

- Jan

How does this work?

Accurate control of the robot is not my biggest concern… it just has to work.

The front wheels are on an axle that is supported at an off-center pivot point. When the rear wheels drive in reverse, the front axle pivots into one position so that the car turns as it backs up. When the motor changes to forward, the front axle moves back to being parallel to the rear one so that the car goes straight.

- Jan

So, something like this? sorry for the sloppy drawing

Yes, exactly. (I would be happy if I could draw that.)

- Jan