Rube Goldberg Machine
What is a Rube Goldberg Machine?
A Rube Goldberg Machine is a multi-step machine that is supposed to complete a task of some sort. Each of the steps causes the next step to happen. Our requirements for this Rube Goldberg Machine were to include 5 simple machines and 10 steps. We had 5 weeks to complete our machine. Here is our machine in motion:
This is our slideshow and video of our machine working. The slideshow includes the theme, simple machines, all 15 steps, calculations, 4 energy transfers, 3 principles of design, the construction log, and before and after blueprints.
Theme
In our machine we had a clear theme of Sponge bob. We tied in the theme with the Sponge bob sky and Sponge bob and Squid wards houses on the bottom. The screws represent waves in the sea.
Construction Log
In our 10 work days we progressed a little more each day. To prepare for this project we made a list of potential theme choices. We chose fishing and started our first blue print.
Simple Machines
Pulley
In our machine we had one big pulley from the bottom right corner, behind the back of the board, and to the top left. When the final weight fell into the cup it pulled the cup down, which pulled the back string and pulls out the wedge. When the wedge pulls out from the weight of the pulley, the wedge drops a ball into the last cup pulley and pulls up a crabby patty.
Lever
The lever was included with our paddle that acted as a seesaw/lever. The ball would hit the paddle and it transferred its kinetic energy to the paddle which hits the next ball. The lever
Inclined Plane
We have 3 inclined planes on our board. Each inclined plane was different lengths. The first one is 34 inches long with a mechanical advantage of 9, the second one is 35 inches with a mechanical advantage of 3.8, and the third one is 24.5 inches.
Wheel and Axle
We incorporated the theme once again with a paddle paddling in the water as our wheel and axle. The ball hits the paddle transferring its kinetic energy to the paddle. The paddle transfers the kinetic energy to the next ball making it move. The first ball starts with potential energy because it is stationary, then it starts down the inclined plane becoming kinetic energy because it's moving.
Wedge
The wedge takes a big part in the final step of the machine. The final ball drops into the cup and activates the pulley with a wedge. The wedge pulls out and completes our final steps of the machine. The wedge is 3 inches by 3 inches by 2 inches.
Screw
We have one screw and a wave type screw. It isn't an actual screw because it doesn't go in the circle. The screws represent waves in the sea of Sponge bob.
Steps and Calculations for Each Step
For some side information, the big ball is 0.577 kg, medium ball is 0.539 kg, and the small ball is 0.518 kg.
Step 1
The ball rolls down the first ramp which is 34 inches long. The velocity of the ramp is 1.1 m/s^2 and the mechanical advantage is 9x slower.
Step 2
The ball hits the paddle and transfers its kinetic energy to the paddle (wheel and axle). We know it is kinetic energy because it started as potential energy when it was not moving, and when it when down the ramp it became kinetic energy when it was moving. All the kinetic energy goes to the paddle.
Step 3
From the paddle getting the kinetic energy it transfers it to the second ball and makes the ball start up. The new ball is potential energy at rest then is kinetic energy when it is transferred making the ball go down the ramp.
Step 4
The ball falls off the ramp at 9.8 m/s^2 (gravity).
Step 5
The ball hits a small ball transferring all of the kinetic energy to the small ball and makes the small ball move down the ramp which is 35 inches. The mechanical advantage is 3.8x easier.
Step 6
The ball goes down a tube that is 35.5 inches in 1.17 seconds. The acceleration of the ball is 30.3 m/s^2.
Step 7
The ball comes out of the tube and hits a board. The board is 3 inches and the space between the tube and the board is 6.3 inches. It takes 4/30 of a second to get out of the tube and hit the board. The acceleration of the ball is 1.2 m/s^2.
Step 8
The ball goes down a set of 3 stairs with a free fall of 9.8 m/s^2 due to gravity. Each stair it goes down is 4 inches and it takes 8/30 of a second to get down all the stairs. The acceleration of the ball is 0.375 m/s^2.
Step 9
The ball hits a big ball with a potential energy and transfers its kinetic energy to the ball. This causes the ball to start motion down the 24.5 inch ramp (inclined plane).
Step 10
The ball hits a weight and transfers its kinetic energy to the weight knocking it over into the cup.
Step 11
The weight falls into the cup. The force of the weight falling is 0.49N.
Step 12
The weight in the cup activates our pulley system! The pulley system has a mechanical advantage of 1 because it has one string.
Step 13
The string pulls out our wedge at the top left corner which has a ball on it. The wedge pulling out is a big part because it leads us to the final steps.
Step 14
The ball falls out of place once the wedge is pulled out of place and goes down the 22 inch tube (screw) with the free fall of 9.8 m/s^2.
Step 15
Lastly, the ball comes out of the tube and falls into the cup. Because of the momentum of the ball going through the tube, the ball activates the last part of the pulley raising the crabby patty from Sponge bob. The person fishing is Plankton because he has always been fishing for the secret formula of the crabby patty.
Reflection
This project was a great experience. It was most definitely a good first project because it had team work and new skills we just learned. I learned how to find the force, mechanical advantage, velocity, acceleration, work, kinetic energy, and potential energy. We did problems from out textbook to practice the equations so that we could use those techniques in our project. I also learned new collaboration skills. I learned to communicate my ideas and build on my teammates ideas. My team worked really well together because of how well we communicated. I think I personally did well as a conscientious learner because I set goals for what I should get done each build day in our maker space. I also set responsibilities for myself such as keeping our work space organized and easy to work in with my team. For my next project I would like to improve on being more efficient with my time. I think I could have leveled out my work between the days more evenly and will for sure do that next project.