Rube Goldberg ‘Non-Soda’ dispenser

The aim of this project is to showcase in a nutshell most of the physics simple machines in action. It also shows transformation of energy from potential to kinetic.

Luke Hanley, Vincent Bett, and Nico Lusardo.

Completed Rube Goldberg Machine

A Rube Goldberg machine is a device that is deliberately over-engineered to perform a simple task in a complicated fashion, generally including a chain reaction.

We designed our machine to dispense water instead of soda. However, there are a series of steps that our machine goes through in order to achieve this goal.

Each step makes use of physics principle from the acceleration of objects due to gravity to the use of gears to increase the speed of rotations.

Big Idea

For our final project, we needed to come up with a device that would use most of the physics topics taught in class. To do this we decided to build a Rube Goldberg machine since such a contraption would have multiple parts with each part illustrating a physics principle.


Before assembling the steps of the machine, we gathered the materials we had that we thought would be useful in demonstrating physics concepts in a sequence.

The Steps of the Machine

Once a switch is pressed, a knife inside an inclined plane slides and pops a balloon. This shows how gravitational potential energy can be converted to kinetic energy.

As the balloon pops, a ball with a string attached to it drops pulling a mound of clay that was attached to a half filled bottle of water.This is an example of how the elastic potential energy stored in the balloon converts to kinetic energy.

The water starts pouting out through a series of tubes to an empty cup. As the cup fills with water, it becomes heavier therefore lifting a lever, which in turn topples a cardboard box with thumbtacks.

The cardboard then pops another balloon triggering yet another ball drop. The falling ball hits another flat funnel shaped cardboard set at an incline. This unsettles some marbles, which begin rolling and collect inside a cup attached to a gear system. As the marbles collect inside the cup, the cup gets heavier and in turn moves downwards.The gear system is attached in such a way that the downward movement of the cup also pulls a string down.

As the string lowers it releases a red ball which stars rolling down another inclined plane. At the bottom of the plane is an NXT robot what moves once its color sensor detects red light. When the ball, which is red in color, hits the robot’s color sensor, the robot drives forward and hits a soda bottle pushing it into a trashcan. The robot also has a touch sensor that commands it to stop once it hits the soda bottle.

Finally, as the soda bottle falls, a sting attached to it pulls open a water bottle pouring water into a glass therefore dispensing water instead of soda.

Calculations, concepts, and simple machines


We attempted to have the marbles that ran down the cardboard to move a gearing system (shown in the left picture) in order to release the red ball on the top of the table, but we had trouble getting this to work. We engineered a new concept for this (in the middle and right pictures) to more easily release the red ball.