Rube Goldberg Machine
What's a Rube Goldberg Machine?
For our first project in the STEM Marin program, we built a Rube Goldberg machine. Named after an American cartoonist and inventor by the name of Rube Goldberg, the Rube Goldberg machine is a series of complex steps that accomplish a simple task.
The Process
The first thing our group had to do was to come up with a theme that our machine could carry out all the way to the final step. We started by making a list of all the themes we were interested in doing. Since we were in groups of four, we had many ideas to choose from. Once we agreed upon our theme--a fair--we thought about a simple task that would suit the theme. We decided our simple task would be a hammer that would ring a bell, like a carnival game. Once we decided on that, we were ready to design a blueprint.
Our Rube Goldberg machine project needed to:
Our Rube Goldberg machine project needed to:
- Contain at least six simple machines (a lever, pulley, wedge, screw, wheel and axle, and inclined plane)
- A lever consists of a rigid bar resting on a pivot; when pressure is applied to one end of the bar, it helps move a load on the other end. The lever on our final project was what triggered the bell.
- A pulley is a wheel with a grooved rim around which a cord passes; it can be used to raise weights. On our project, the pulley starts the ferris wheel.
- A wedge is a piece of hard material that is slanted at an acute angle to make something go down.
- A screw is a twisted inclined plane (see below) that converts rotational force to linear force. Our screw dropped the weight that started the tennis ball around the ramp.
- A wheel and axle is a wheel with a rod through the center that rotate together. In our case, the wheel and axle was the ferris wheel.
- An inclined plane is a ramp that allows something to go up or down. Our incline plane was the roller coaster at the very beginning.
- Have at least four energy transfers (potential energy to kinetic energy)
- Potential energy is the energy that is stored in an object at rest. The still marble at the start of our Rube Goldberg machine sat there with potential energy.
- Kinetic energy is the energy of moving things. When the marble was set in motion, it picked up kinetic energy.
- An energy transfer is when energy is transferred from one object to another. Potential energy transfers to kinetic energy when an object goes from being at rest into motion. The moment the marble was set in motion, it began transferring potential energy into kinetic energy.
- Include a minimum of ten discreet steps
- Incorporate design principles
- Work successfully to accomplish the simple task
- Make a strong presentation
Construction log
On day one of the building stage, we cut the big board that was given to us into two pieces and attached two blocks of wood to the baseboard. On day two, we attached two blocks of wood to the back to keep our structure solidly upright. The next day, we cut out two large circles for the ferris wheel and started shaping the screw. On day four, we attached the first pulley and attached planks of wood to hold up the roller coaster. We also connected a ramp to support beams to complete the roller coaster. On day five, we cut out a circle for the carousel and put a tube through it. We attached gears underneath the carousel and, later that day, we connected the ferris wheel to support beams. On day six, we attached the screw and the box underneath it. We also attached the second pulley and connected the string on the pulley to the gears underneath the carousel. On day seven, we attached a wheel and axel to the carousel and created the weighted “hammer." We also attached the hammer to a block of wood on each side. On the second to last day, we attached the lever that the hammer would hit and attached the bell tower. We spent the final day decorating the structure to fit our theme (painting, adding figurines, etc.) and testing our design.
Calculations
Velocity is speed in a given direction.
velocity = distance/time
v=d/t
Acceleration is a change in speed.
acceleration = velocity/time
a=v/t
Force is the strength or energy put into something.
Force = mass x acceleration
F=ma
Work is the amount of effort you put into something.
Work = Force x distance
W=Fd
Mechanical Advantage is how many times easier something is.
Mechanical Advantage = Force effort/Force load
MA=Feffort/Fload
or
Mechanical Advantage = distance load/distance effort
MA=dload/deffort
Potential Energy is the energy that is stored in an object at rest.
Potential Energy = mass x acceleration due to gravity x height
PE=mg*height
velocity = distance/time
v=d/t
Acceleration is a change in speed.
acceleration = velocity/time
a=v/t
Force is the strength or energy put into something.
Force = mass x acceleration
F=ma
Work is the amount of effort you put into something.
Work = Force x distance
W=Fd
Mechanical Advantage is how many times easier something is.
Mechanical Advantage = Force effort/Force load
MA=Feffort/Fload
or
Mechanical Advantage = distance load/distance effort
MA=dload/deffort
Potential Energy is the energy that is stored in an object at rest.
Potential Energy = mass x acceleration due to gravity x height
PE=mg*height
Reflections
Our group was overly ambitious. We had wild ideas that were very hard to pursue (for example, we didn't build up enough force to drop the weight that would ring the bell at the end of our Rube Goldberg machine--if we had come up with something simpler that required less force, we could have accomplished it more regularly). We learned that sometimes it's better to stick with a simple design than commit to an unrealistically complex one. We also learned how to share ideas respectfully, how to compromise without hurting feelings, and how to collaborate even when we were frustrated. The project tested our patience because our machine rarely worked successfully all at once. But when it succeeded once from start to finish, it was thrilling!