Engineering Projects/Rube Goldberg/Howard Community College/Spring2012/p1501-SZ

Problem Statement

To create a Rube Goldberg machine that functions through the use of dis-assembled printers, leading up to a Rube Goldberg machine as shown in the OK Go video "This too shall pass."

Team Members

Zechariah Bennett

Lemuel Sun

Summary

The team spent the last four weeks continuing construction on a Rube Goldberg machine. The machine was constructed using parts exclusively from dis-assembled printers. Solenoids were used to impact the gear axle rods, which were used as chimes of a sort. The gear assemblies were connected together using belts and rubber bands.

Poster

Story

At the start of the allotted four weeks, the team decided that it did not want to be limited solely to gears and belts. In order to expand the functionality of the Rube Goldberg machine, the team decided to use the solenoids within the printer to act as hammers, which would impact chimes of varying pitches. These chimes were made from rods of metal that had gears attached to them within the printers. A major obstacle that was encountered during this process was that one of the solenoids would "stick" after the electrical current to it was cut. This was due to remanence, which is essentially residual magnetization of the ferrous core within a solenoid. When the current is passed through the solenoid, a weak permanent magnet is created, which loses its magnetization over time, causing this "sticking" effect. This was combated by applying the electrical current in very brief bursts, just long enough to cause the solenoid to activate. After this was solved, the team mounted the Rube Goldberg machine on a stand. After successfully mounting the machine, it was realized that the legs of the stand wobbled whenever the machine was pushed around. To solve this, the team attached a cross-brace to the legs of the stand, which stabilized the stand. The team then connected the various printer boards together with the use of heavy duty rubber bands and belts. However, one of the gaps between boards was longer than the length of our longest belt, so the team had to create a belt which spanned the gap. First, blue painter's tape was used, which proved effective. To improve on this idea, the team tested various tapes, including masking tape and duct tape. Of the three, blue painters tape maintained as the most effective. Later on, string was used which ended up being the most effective of all the materials tested. It did not have the crunching noise that the tape made, and was much easier to replace if damaged.

Decision List

Primary Focus	Simplest to Build	Cost	Expandability	Total
Multiplier	1	1	1.5
Mechanical	3	1	2	7
Gravitational	2	3	4	11
Domino Effect	4	3	5	14.5
Mixture of All	2	2	2	7

Sam

Primary Focus	Simplest to Build	Cost	Expandability	Total
Multiplier	1	1	1.5
Mechanical	2	1	3	7.5
Gravitational	4	3	1	8.5
Domino Effect	2	2	1	5.5
Mixture of All	2	1	1	4.5

Zechariah

Material List

Currently used:

Material	Quantity	Size	Cost
Printer Gearboxes	4	Various	None (found in backroom)
Arduino	1	Small	None (found in room)
Motor	3	Medium/Small	None (found in room)
Screws/Nails	Several	Medium/Small	None (found in back room)
String	Several	Medium/Small	None (found in back room)
Wheels	4	Small	None (found in back room)
Fabricated wind chimes	2	Medium/Large	None (found in back room)

Future acquisitions:

Material	Quantity	Size	Cost
Tubes (metal/pvc/cardboard)	Unknown	Various	None (found in backroom)
Solenoid	Unknown	Small	None (found in room)
Power Supply 24v	Several	Medium/Large	Unknown (preferably salvaged or scavenged)
Ball	Several	small/medium	None (found in room)
Screws/Nails	Several	Medium/Small	None (found in room
Wooden Board	Several	Large	Unknown (preferably salvaged or scavenged)
String	Several loops	Medium/Small	None (found in back room)

Future acquisitions will vary based on what kind of devices we decide to mount and incorporate

Software List

Arduino Software installed on Laptop: allowed for the control of devices like the motor through various programs implanted on the arduino

Time

13.5 Hours

Tutorials

Arduino tutorials

Guide to laser printer motor

Next Steps

1. Figure out why solenoids "stick"

2. Mount motor, power supply, and other various electronic equipment to the board

3. Devise way to make all electronic functions hands free (ex: flip switch, motor comes on)

4. Connect the rest of the gears (most likely using string)

5. Incorporate different mechanisms and possibly a ball