Extreme Science: Penny Shine

What you will need:

  • Tumble toy template (printed on card stock paper)
  • Tape or glue (hot glue works the best)
  • Large marbles or steel bearings
  • Cardboard ramp
  • Adult supervision


  • Piece of card stock paper approximately 3”X10”
  • Ping pong ball (carefully cut in half)
  • Razor knife (adult use only)


1. Print the tumble toy template on a piece of card stock or heavy stock paper and cut along all SOLID lines. Fold on dotted lines.

2. Bring one end up as shown making sure that the paper curls around the rounded part of the template. Glue this half in place.

Note: Hot glue works the best since it cools off and holds quickly. If using liquid glue, you will probably need to tape this in place and wait until it fully dries before going on to the next step.

3. Place two large marbles or steel bearings inside of your tumble toy and roll the remaining flap up and over in place as shown. Glue this flap just as you did during previous step.

4. Once all of your glue is dry, place your tumble toy, standing upright, at the top of your ramp as shown and let it go!

Optional method

1. Have your parents CAREFULLY cut a ping pong ball in half.

2. Take your 3” X 10” piece of card stock or heavy stock paper and roll it up to create a tube that is 3” in length and just small enough to fit in the end of one of the ping pong ball halves as shown. Glue this in place using hot glue.

3. Place a large 1” steel ball bearing inside of the tube and glue the other half of the ping pong ball on the other end as shown:

4. After glue is dry, place your tumble toy on the ramp standing upright and watch it go!

What is going on?

Gravity is pulling on the ball inside of the toy causing it to roll down the incline plane. As the ball rolls down inside of your tumble toy, it picks up speed gaining momentum. As it reaches the end of the toy, it impacts the lower end with force. This force is great enough and has enough energy to lift the opposite end of the tumble toy. This impact begins the rotation of the toy causing the other end to rotate down the incline plane allowing the ball to again roll forward repeating the process.

Try this:

Try changing the size of your toy. What do you think will happen if you make it longer or shorter? What would happen if you put several small marbles inside rather than one or two large marbles or steel bearings? Will it still work? How long or how short can you make it and have it still work?

Radical Rick

Extreme Science



Recommended for you