# 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.

### 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