Background
The Rube Goldberg Machine was invented by engineer, cartoonist, and Pulitzer Prize laureate, Rube Goldberg (1883-1970). After his initial career as a mechanical engineer, he used his engineering background and applied it to his artistic skills to produce over 50,000 cartoons with Hearst Publications. His works included convoluted methods from waking up in the morning to his "Revolveometer", used for viewing abstract art.
The Project
Objective: We were to plan, build, calculate, and present a thematic Rube Goldberg machine over a course of 9 days.
Key Concepts and Terms |
Application of Physics |
Vector Quantity: A unit with direction assigned.
Scalar Quantity: A unit without direction assigned. Time (t): Progress of events, measured in seconds, s. Distance (d): Amount of space between two points, measured in meters, m. Height (h): The vertical distance either between the top and bottom of something or between a base and something above it, measured in meters (m). Velocity(v): Rate of distance travelled in a direction, a vector quantity measured in meters/second or m/s and direction. v=d/t Speed (s): Rate of distance covered, scalar quantity measured in m/s. s=d/t Acceleration (a): the rate of change of velocity per unit of time, measured in m/s². a= v(final)-v(initial)/time Acceleration Due to Gravity (g or a sub g): Gravity is a force between two objects, directly proportional (~) to their mass and the distance between them. The gravitational constant is 9.8 m/s². For falling objects: v=gt d=1/2*gt² Mass (m): The amount of matter and weight of atoms in an object, measured in Kilograms (Kg). Force (F): The intensity of body or system, producing or tending to produce a change in movement or in shape or other effects. (A push or pull on an object). F=ma, measured in Newtons (N) Work (W): Amount of energy put into something, measured in Joules (J). W=PE=KE W=Fd Gravitational Potential Energy (PE sub g): Energy an object has due to position at a height in a gravitational field, measured in Joules (J). W=PE=KE PE=mgh Kinetic Energy (KE): energy that a body possesses by virtue of being in motion, measured in Joules (J). W=PE=KE KE= 1/2*mv² Simple Machines: Any of the basic mechanical devices for applying a force, or changing direction. There are six simple machines: Inclined Plane (Ramp), Wedge, Lever, Pulley, Wheel and Axle, and Screw. More information can be found in the following websites: http://www2.phy.ilstu.edu/pte/489.01content/simple_machines/ simple_machines.html http://www.explainthatstuff.com/toolsmachines.html Mechanical Advantage (MA): the ratio of the force (or distance) produced by a machine to the force (or distance) applied to it, used in assessing the performance of a machine, in terms of the times easier. |
A 26 gram spherical mass rolls down a 2 inch high inclined plane with a mechanical advantage of 1.25, colliding with a 31 gram block of walnut wood after 0.5 seconds, giving an average speed of 25 cm/s, and a loss of 0.005 J of PE due to gravity.
The block of wood then topples, due to the toppling effect, which states that when the center of mass of an object is outside the object’s footprint (base), the object topples. Therefore, the block of wood topples, knocking the other block of wood, producing another toppling effect that moves the second block of wood forward, knocking into a paintbrush. Next, the effort of the block of wood falling is applied toward the brush part of the paintbrush, making the paintbrush fall, rotating around an axle, knocking a metallic ball that will be explained in the next step. The paintbrush acts as our wheel and axle, with a mechanical advantage of 0.875. The paintbrush collides with a 16.4g spherical mass that travels down 4 inches by way of an inclined plane with a mechanical advantage of 1.5, and an inclined plane with a mechanical advantage of 2. This provides enough speed to propel the mass to trigger the next step; the first pulley assembly. The first pulley has a mechanical advantage of one, meaning that the pulley alters the direction of the effort. A mass of 109.7g was used to produce a force of 1.08N to raise the opposing platform. A wedge prevents a 19.2g mass from moving across a 6 inch plane until the plane is raised to a 115 degree angle. The ball then rolls down the plane, which acts as an inclined plane with a mechanical advantage of 0.93. The mass then falls a distance of 18 inches, accelerating at 9.8m/s squared. The average velocity is 45 inches per second. The force of the mass is 0.188N. The tambourine, at a 45 degree angle, then alters the path of the sphere to a more horizontal arc. A 400g mass sits upon the left side of a class two lever. The adding of the spherical mass tips the lever to the left. The 400g mass rolls onto a waiting ramp with a mechanical advantage of 48, dragging a string. The string is pulled across a pulley with a mechanical advantage of one, raising a 43.5g cloth 4 inches. |
Overview of Steps
Step One: The Rube Goldberg begins with a soccer ball being pushed down a ramp onto a wooden plank.
Step Two: The ball then transfers its kinetic energy into 2x7 inch walnut wood plank that falls, transferring its kinetic energy into another 2x9 inch walnut board. Step Three: The second 2x9 inch wood plank attached to the ramp by a hinge falls and transfers its potential energy into the paintbrush, allowing the brush to swing around a screw (axle) and make contact with the side of a canvas. Step Four: The paintbrush continues its circular path to hit a metallic ball perched on the end of a wedge, making the ball roll down two inclined planes. Step Five: The ball then drops into a weighted cup, activating the pulley system to pull a lever on the opposite side upwards. Step Six: Kept in balance between two opposing wedges, a green ball is lifted along with the wooden lever by the pulley to an angle in which it rolls off the lever and into a free fall. Step Seven: The green ball lands on the top of a tambourine, transferring kinetic energy to the tambourine, making a vibration or sound, and then continues its path onto a wooden board with all the momentum from the free fall. Step Eight: The green ball then transfers its kinetic energy into an angled wooden block, which then pushes a forty gram weight attached by string to another pulley system off the end of the wood. Step Nine: The weight is dropped by a lever onto an inclined plane where it is stopped by a wedge at the end of the board. Step Ten: Because the weight moved forward, the other side of the pulley is moved upwards. The string on this end is tied around a piece of cloth, which is pulled out of tie dye and suspended in air. Construction Log SummaryOur endeavors to construct this Rube Goldberg Machine started with the independent brainstorming of individual sequences of steps. Afterwards, we came together and decided that our theme would be “The Arts”. We each cobbled together blueprints, involving no less than twelve steps, and using an ambitious six simple machines. This, we would learn, was a mistake. The next nine days that we had were used to actually construct the machine, and can be read in more detail in our construction log (unabridged version). The final three days that we had leading up to this presentation were used to finalize the project, and also to review our work in the form of calculations. |
Construction Log Unabridged
Day One:
Our endeavors to construct this Rube Goldberg Machine started with the independent brainstorming of individual sequences of steps. Afterwards, we came together and decided that our theme would be “The Arts”. We each cobbled together blueprints, involving no less than twelve steps, and using an ambitious six simple machines. This, we would learn, was a mistake. Day Two: One the second day, we reviewed our blueprints, got them approved, and began to search for the necessary supplies in order to construct the machine. Part of our group also started to mark out the exact placement of some objects on our board.We immediately hit a couple of snags when we discovered that as we were the later class, the earlier class had already taken a number of crucial supplies. Day Three: On the third day, some of us made our initial foray into the land of power in order to begin the construction process in earnest. However, we may have been a bit over enthusiastic, as at the end of the day, we had achieved the affixation of no less than a single piece. Day Four: On our fourth day, we started to make up for lost time, and affixed the initial plane of wood, and marked out the proceeding steps. We also started to brainstorm materials that could be used for the chute that we had planned to start our machine. Day Five: At the start of the fifth day, we attached the second “layer” of materials, including the two inclined planes coming down from the canvas, and the piece of wood immediately after the pulley. We also started to think about how to achieve our blueprint design with the first pulley. Day Six: Our sixth build day was mainly devoted to assembling the rest of the second layer and attempting to start on the final steps. We added the first pulley, but the assembly that goes along with it was not ready for final attachment. Day Seven: On our seventh build day, we began to see how little time we had left, and started to work at lunch. However, this program was interrupted by forgetful group members and conflicting schedules. We started the final lever assembly, and began to delegate the bringing of the final supplies that were still needed. Day Eight: On our penultimate build day, we began to cut out sections that would not work. We cut out the beginning ascension of the ball, and also decided to remove the screw channel from our complex system of supposedly “simple” machines. Day Nine: During our final official build day, we started to finish up the basic works of our machine, as well as starting to decorate the machine with the designs you see now. After this day, we finished the project at lunchtimes and after school, fine-tuning the details of our machine. |
Principles of Art Design
Rhythm can be found throughout the entire Rube Goldberg with our music theme, the most obvious example being a tambourine hit. The different sounds create a sort of pattern through the different beats and tempos, composing a mechanical orchestration. The entire machine has to come together with balance, the pulley and lever systems depending upon it. The constant visual movement is exhibited mainly through the balls, paintbrush, weights, and tee shirt. The variety of materials creates contrast throughout the machine, yet also helps the elements work together for harmony all surrounding the theme of music. The canvas and music sheets are the machine’s emphasis, due to the different color and texture. However, the three-dimensional design of all parts of the Rube Goldberg also are emphasized against the wood plank. These wood planks are of all different lengths with no proportional relationship, but mainly are short enough to stay on the board.
Documents
Blueprints
Video
Powerpoint Presentation
Project Reflection
During the infancy of the project, where we had only had the theory of the machine, I was pessimistic about the true function of the machine. This was primarily due to the complexity that was involved in the creation of some of the steps and making sure that the project had fluidity. But I had my utmost faith in my group members to ensure the completion of this project. As the project progressed, the use of time, especially in the dealings of the conflicts between idealism and pragmatism, had taken a toll on our product. We hadn't watched the clock closely enough, and also hadn't brainstormed in an effective manner, as we spent too much time thinking about approaching a problem, instead of acting on our problem. Sometimes when we did act on our ideas, and would hinder us and further the struggle for better time efficiency. For example, we initially had a screw that would lead in to the tambourine step, and a chute that would launch a ball up to a tube and initiate the machine. When we had spent so much time on an idea that wasn't practical, especially when resources were scarce, spending our time on these endeavors hadn't promoted progress. Under those circumstances, we realised that the work we do for the few and final days had to be the hardest, with a mindset for completion and perfection, and with this we had concluded our work on the product to the best that we could make it. After all this done, I learned and gained very important lessons and skills to keep in mind for the future from this project. For example, when we had a shortage of resources I had to learn to be crafty and resourceful. I also learned the importance of doing instead of excessively thinking, which would also impact the way I now see how I should handle time constraints. In addition to this, I also saw areas of personal improvement, like being more assertive, articulate, direct, and concise about the way I present my thoughts, and making inclusivity from other teammates, especially trying to use people's strengths for better productivity, one of my primary concerns. Overall, I am proud of the final product achieved, and the hard work that the whole team put into the project.
-Nihal Nazeem
-Nihal Nazeem