The Rolling Marbles
Hello, our names are Ellie B. and Tyler K. We are freshmen in high school at the Dreyfoos School of the Arts and The Benjamin School, respectively. Our Energy Transfer Machine took us over three months to complete. We were inspired by our last machine, which had several flaws. In this machine, we wanted to both correct those flaws and improve our design capabilities. Our adult helper was Susan Bickel. Below is our video explaining the steps of our Energy Transfer Machine and our actual run.
Our Steps:
- Stomp rocket compresses air forcing the rocket to launch.
- The rocket launches, pulling a string.
- The pulled string in turn pulls a piece of cardboard out of the foam insulation tubing.
- Gravity pulls the marbles down to the turbine.
- The marbles hit the turbine, forcing the blades to spin.
- The blades of the turbine spin a wooden dowel.
- The wooden dowel has a weighted plastic cup attached which lowers as the dowel spins.
- Attached to the plastic cup is a strip of paper that is pulled down with the cup.
- The end of the paper is embedded between two wires attached to a battery-powered mower. When the cup reaches the bottom, the paper is pulled out, allowing the wires to connect and complete the circuit.
- When the circuit completes, a fan blade spins.
- The fan blade knocks a balanced marble.
- Gravity pulls the marble down a foam tube.
- The marble falls down a hole and knocks into wooden blocks which domino down.
- The last block hits a small, green car.
- Gravity pulls the car down a track.
- The car hits a lid.
- The lid moves.
- The movement causes a metal ball bearing to move down a tube.
- The ball-bearing zig-zags down a track and drops into a plastic cup.
- The plastic cup falls.
- The string attached to the plastic cup pulls a foam piece out of another tube releasing a marble.
- Gravity pulls the marble through a tube which includes a loop de loop.
- The marble knocks over a graduated cylinder capped by a balloon.
- The graduated cylinder contains a citric acid solution and the balloon contains baking soda.
- The balloon blows up.
Step on the Stomp Rocket to start the ETM. 
The string attached to the rocket releases the marbles, causing the turbine to spin. 
When the turbine spins, a piece of paper attached to the lowering cup falls away, allowing the circuit to be completed. 
The completed circuit powers a fan, which releases a marble to knock into a row of blocks. 
The blocks hit a green car. 
The green car hits a marble, which falls into a cup, releasing another marble into a loop-de-loop, which then knocks over our chemical reaction.
Our Battery:
We used a battery-powered motor to spin a fan. The fan then knocked a marble. The circuit was prevented from completing by a strip of paper, which was pulled away by a cup lowered by our turbine, allowing the circuit to complete.
Our Chemical Reaction:
We filled a balloon with baking soda and attached it to a graduated cylinder filled with a citric acid solution. When our graduated cylinder was knocked over by a marble at the end, the balloon inflated, our end goal.
Our Process and Problems:
Thank you for considering our project, we spent a lot of time on it, and we hope you enjoy it!
Wow, that was very complex and I can see how you really put the effort in to make it work. Great team effort, congratulations!
Thank you for your comments!
I really enjoyed your Energy Transfer Machine. The part with the fan and the small bucket being lowered slowly until it completed the circuit was great–it stretched out the machine run time and also created a lot of suspense. The photos that you took during the building process were also a good touch….they help to explain all the work that went into creating your machine. Good job!
Thank you for your comments!
Hello! I am one of the team members, Ellie B. The balloon did blow up at the end, but our teacher got overexcited and ended the video before it fully inflated. We had to run the machine many, many times over multiple work sessions to get everything working correctly, and in the right order. Thank you for your comments!
Great documentation of your project on this page, I also like seeing the photos of you both building it. The lowering cup was a great idea, I’ve never seen that used in a step before, great way to add time to your project. Did the balloon blow up at the end? I couldn’t tell. The use of the stomp rocket was a cool way to get things started. How many times did you have to run this to get it to work all the way through?