By: Daniel Worstell

He was an inventor/cartoonist who is known for his cartoons of extremely complicated machines designed to perform ordinary, mundane tasks. The humor in these diagrams was because of the fact that they could be completed in a much simpler manner, but the complexity required delicate attention to detail when creating such machines. Every year, a number of “Rube Goldberg machines” are created by people emulating his cartoons. Goldberg also worked as an inventor, engineer, author, and sculptor during his lifetime. Goldberg was inspired to begin drawing his machines came from his studying engineering at UC Berkeley, and the beginning of the “machine age” in the United States. This was a period of rapid industrial development, marked by the creation of complex machines to simplify life, and his work was a sort of satirical take on the development of life.

Inspired by Mr. Goldberg’s art, I decided to take a shot at emulating his famous cartoons. Successful completion of the machine required knowledge in a number of fields of Physics, listed below: -Hydraulics -Standard Mechanics -Simple Machines and their applications -Gravity, its effect on objects, and its strength relative to other forces such as friction -Centripetal forces and their manifestations through objects such as pendulums/circular motion -Inclined Planes and their effects on motion -One dimensional and two dimensional kinematics -Collisions -Limiting error and error analysis -Electrodynamics -Magnetism

To get this project done, it took months. I had to allow myself enough time each week to do 4- 5 steps, and continuously seek out sources of error.

Steps 1-5 were completed 1) Pull out the nail allowing the ball to roll (Gravity, Friction) 2) Ball rolls down ramp with increasing Kinetic Energy (Gravity, Inclined Plane, Friction) 3) Ball collides with homemade ball-stopper (Friction, Kinematics) 4) Ball-stopper pulls on string as it falls (Gravity, Tension, Friction) 5) String pulls rock off ledge (Tension, Friction)

Steps 6-10 were completed and Week 1’s work was assessed/repaired. A major source of failure was the original ramp design, which was totally revamped. A persistent source of failure was and is, however, the rock falling. In this week, a new source of failure became apparent – the dominos. 6) Rock pulls new string in a new direction as it fell (Kinematics, Tension, Gravity). 7) String pulls open hinged car-stopper (Tension, Friction, Gravity) 8) Car rolls down ramp (Friction, Gravity, Inclined Planes) 9) Car collides with first domino (Collisions) 10) Series of Dominos falls (Collisions, Friction)

This is where the project got interesting – the introduction of hydraulics. Surprisingly, in this section, error is relatively low, perhaps because of the large funnel used. 11) Dominos strike Hinged Cup filled with water (Friction, Collisions, Hydraulics). 12) Hinged Cup swings downward (Friction, Gravity, Hydraulics) 13) Hinged Cup releases salt-water contents (Gravity, Hydraulics) 14) Salt Water pours through funnel (Gravity, Hydraulics) 15) Salt Water emerges, pours into a cup (Hydraulics, Gravity)

This section is the most error-prone in the system. The introduction of electrochemistry/electrodynamics is likely to blame for this – possibly because the circuitry and wiring used in this section is not designed to pass through an electrolyte. Normal electrodes quickly corroded in the electrolytic solution, so I made single-core paperclip electrodes which would not corrode. 16) Electrolytic solution completes a previously made circuit (Electrodynamics, Gravity, Hydraulics) 17) Circuit causes a motor to spin (Electrodynamics, Friction [particularly important – any catches stop the motor]) 18) Motor causes a bobbin to spin (Friction, Centripetal Forces, Electrodynamics 19) Bobbin reels in string (Tension, Centripetal Forces, Friction) 20) String’s force direction changes and is multiplied from to a pulley (Pulleys, Gravity, Tension)

This part is slightly error prone as well, but does have a relatively high success rate. Particularly annoying was the fact that one marble rarely carried sufficient force to separate the magnets, so I ultimately used three. 21) String pulls up on needle wrapped in duct tape (Friction, Gravity, Tension) 22) Needle releases three marbles (Friction) 23) Marbles begin rolling down plane (Friction, Gravity, Inclined Plane) 24) Marbles collide with two magnets [hair trigger] (Collisions, Friction, Inclined Plane, Gravity) 25) Two magnets release their grip on each other (Magnetism, Collisions, Gravity, Friction)

By this point, the project’s creation was coming to a close. The remaining steps have relatively high success rate, but sometimes there are unexpected failures (as with any in a Rube Goldberg Machine) 26) Magnets releasing allow sandbag to fall (Gravity, Magnetism, Friction, Tension) 27) Sandbag collides with mousetrap (Friction, Springs, Collisions, Gravity) 28) Mousetrap realigns sandbag’s course (Collisions, Springs, Friction, Kinematics) 29) Sandbag collides with two magnets duct taped to the top of a spring-loader (Collisions, Gravity) 30) Magnets depress loader (Collisions, Gravity, Friction, Springs)

This was the last week of step-creation. It also, unfortunately, tends to be relatively failure-prone, particularly due to the necessity of aiming-by-eye of the sandbag to the launcher and the need for the “easy” button to be in the correct placement each time with allotted rebound space. 31) Spring-loader launches fork forward (Springs, Friction) 32) Fork collides with “That was Easy” Button (Collisions, Friction, 2d Kinematics) 33) Button relays message: “That was Easy” [No, it was not easy] (Audio, Collisions, Friction) Just because my creation was done did not mean I was done with the project, however. The remainder of the weeks leading up to the project were filled with error analysis, testing, testing, testing, and more testing.

Scissors cutting string – It would be cool, but would have cost a lot of string and taken a lot of time to reset Pendulum swing – Pendulums are hard to come by Mallet swing – the forces required to release a mallet or the forces it would release were much higher than those I could reliably control Sailboat and tank of water – I did not have either the resources or time available to undertake this section Physics of air with a fan – Unfortunately, the forces involved were far to small to be feasible in my machine Turbine use – I could not get a hold of a turbine Food use – This would get very messy Rubber band entanglement – There was no place for this in the machine.

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