Introduction:

In this lab you will design a simple Rube Goldberg Machine. The basic idea is that this machine performs a number of overly complex steps in order to complete a simple task. The images below should clarify this idea. We will present more detail in lecture.

For more information on Rube Goldberg machines, including an annual national contest, visit the Official Rube Goldberg website.

As you walk past cobbler shop, hook (A) strikes suspended boot (B), causing it to kick football (C) through goal posts (D). Football drops into basket (E) and string (F) tilts sprinkling can (G), causing water to soak coat tails (H). As coat shrinks, cord (I) opens door (J) of cage, allowing bird (K) to walk out on perch (L) and grab worm (M), which is attached to string (N). This pulls down window shade (O), on which is written, "YOU SAP, MAIL THAT LETTER."

Challenge Statement:

Build a Rube Goldberg Machine that tosses a ball into a target region. Your machine should consist of at least 5 energy transfers (steps). You may generate your own electrical potential, or utilize more creative source, as long as you do not use a commercial product (like a battery, power supply, or outlet power). Chemical reactions and flames are allowed within reason. Be sure to alert the lab TAs beforehand if you are planning on significant amounts of either. You may use any materials you can find except for those involving commercial sources of electrical potential as indicated above. Each step should be unique and contribute to the goal. For example, this means you cannot have a rolling ball hit a few pins on its way down a ramp and have those actions count as steps. If you have questions, email the lab TA.

The ball being tossed may range from 35mm to 50mm in diameter. Common balls in this range include golf balls, ping pong balls, and others. The target region will be a 2' by 2' square placed on the floor 2' from the base of the machine. The ball must land directly within the target region, rather than bouncing or rolling in. It can, however, bounce or roll out of the region after landing in it.

Up to two human interventions are permitted: one to start the machine, and one to intervene if something unexpected occurs. In an attempt at a chain bonus (see below for details on bonus points) each chain gets 3 total interventions (including the starting push). If attempting a whole class chain, only 1 total intervention is allowed for the class (still including the starting push). Additionally, if attempting a whole-class chain, it must work on the first attempt!

Size Constraints:

Base: 3' x 4' maximum
Height: 5' maximum
Ball: 35 to 50mm
Target: 2' x 2' (provided by TA)

Hand-in:

Your group's Rube Goldberg Machine
A copy of the grading sheet.
Email the lab TA a URL for a web site that:
- Depicts your Group's name and members' names.
- Contains pictures of your Rube Goldberg Machine.
- Lists the energy transfers.

Evaluation:

Grading:

+5 points if the ball lands in the target
A (90): 5 energy transfers (steps)
B (80): 4 energy transfers (steps)
C (70): 3 energy transfers (steps)
D (60): 2 energy transfers (steps)
F (50): <2 energy transfers (steps)
F- (0): No machine at all

Bonus Points!

Two bonus points will be awarded if your machine can be attached to another group's machine and the two machines can run in SERIAL to create a larger (10+ transfers) Rube Goldberg machine. If three or more machines can be attached serially (15+ transfers), three additional points will be given for a total of 5 bonus points per team. Please notify a lab TA by 11:59pm Sunday, January 18th with a list of the teams involved if you wish to pursue the bonus points. In addition, be sure to specify the orientation of how the machines connect. (in a line, with a 90 degree bend, etc)

A serial connected Rube Goldberg Machine is defined as one whose first energy transfer is initiated by the final energy transfer of the previous machine.

In this case, the launched ball must trigger the next machine. The machine bases must be placed 2' apart, and the trigger target area can be no larger than 2' by 2'. Each machine must have at least five isolated energy transfers, and must be able to operate independently, in addition to the connected configuration.

In addition, 5 bonus points will be awarded if the same ball is used from beginning to end on a chain of three or more machines. The same ball must launch from the first machine, trigger the second machine, be launched by the second machine, and so on. The final machine in the sequence must still land the ball in the target area.

Examples

Some videos of previous years' machines:
Cracking an egg
Pouring a can of soda with a mouse
Pouring soda with Dominoes

Famous Honda 'Cog' Commercial:
Quicktime
Flash

A really sweet Rube Goldberg machine - as cool as Honda's 'Cog' Commerical

Another Rube Goldberg Machine

The Pittsburgh Tribune-Review's article on the Spring 2002 machines.

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