Rube-Goldberg Device. Team #1; A1, 4/28/10. Matt Burr, Kayla Stone, Blake Hanson, Alex Denton

Size: px

Start display at page:

Download "Rube-Goldberg Device. Team #1; A1, 4/28/10. Matt Burr, Kayla Stone, Blake Hanson, Alex Denton"

Arron Lang
6 years ago
Views:

1 Rube-Goldberg Device Team #1; A1, 4/28/10 Matt Burr, Kayla Stone, Blake Hanson, Alex Denton

2 Introduction The main goal of our team when creating the Rube Goldberg machine was to construct an inefficient but consistent, and easy to operate device that would operate an electrical device. Our secondary goal was to interact with the other devices in our class. It was also our objective to present our design process, operation, and calculations to our peers in an interesting, easily followed format. We aspired to accomplish these goals through collaborating with each other about the design process, and working together to put our plans into action. Each member made a valuable contribution to the creative process, and played a key role in the production of the device and the presentation. Construction of the Device and Materials Used Most of the materials used in the construction process were found in a storage shed. Some additional material supplied from the Estabrook lab. We estimated the construction cost of the garage type items to be about twenty dollars. We began with the design of the device in theoretical sections. We formulated the ideas of using a mouse trap, an elevator device, some kind of ball rolling on a track, a sliding or rotating block as well as other ideas. The materials that we used were wooden planks, ply wood, bolts, screws, metal and plastic tubing, a mouse trap, fishing line, batteries, electroluminescent wire, bearings, hinges and tape. Tools used in construction were items like electric drills, a wood saw, Dremel tool, and various other hand tools. We began constructing our device over the course of several days. Approaching completion we continually made minor adjustments to the device allowing it to operate with better stability and consistency. When the system was complete we had a total of ten individual devises operating within the mechanism as a whole.

3 Description of the Device The device was theoretically going to be set off by a hot wheels car setting off a mouse trap. A piece of fishing line attached to the mouse trap arm creates tension. The tension is then used to spin the vertical shaft. Installed on the shaft are two fly weights. These fly weights then swing out to form a collision with a gate. The collision then moves the gate that releases two balls positioned on a track. The balls roll down the track and drop into a bucket that is suspended by monofilament fishing line. The line tension is used to create torque on a second horizontal shaft. The rotation of this second shaft reels in another fishing line that pulls a pin holding a one by two inch block in place, allowing the board to fall freely. The board then hits a release wire and allows a hinged sign to swing down. As the sign falls it releases tension on a micro switch that was creating an open circuit between the battery and the inverter/driver puck. Once power is restored to the driver puck an alternating current then illuminates the electroluminescent wire on the sign. This swing of this sign then triggers a release mechanism allowing a piece of thin tube to swing out and start the next group s device. Calculations and Equations Having as many steps as we did made for some complex calculations. We decided to take a simpler approach and look at pieces and instances. The data could be combined further in detailed integrals but that is outside the scope of the project. The first of our applications of physics were linear tension. This was measured by taking measurements with a scale every 10 degrees. The highest of which was ten Newton s. This data was compiled in an Excel spreadsheet and combined with the linear distance traveled. Page two of our spreadsheet uses the equation torque equals force multiplied by the moment arm. Our highest torque was Newton-meters. A graph of these results can also be found on this page. The next calculation was acceleration. The formula acceleration equals torque divided by mass moment of inertia was used. This was charted against rotation intervals. The intervals correspond

4 to the mousetrap s linear travel, and thus the angular travel. At various rotating angles we can see the torque generated by the mousetrap tension. Our highest acceleration was 1040 radians per second per second. It was observed that the fly weights pulled to full height in less than one turn. Some of our other calculations included potential gravitational energy. With two meditation balls the elevator had a mass of kilograms. Using mass multiplied by gravity multiplied by height we have joules of potential energy in meters of travel. Problems and Difficulties There were a few problems that we had to solve after the construction of our device. The gate device we used to release the balls down the track did not work consistently. Our decision was to move the pivot to allow the contact point to be in line with the first ball s center of mass. This put the force of the balls trying to roll in line with the pivot. The gate now makes less of a full swing to release the balls and allows us to use a spring to start the rolling motion once released. This also allowed the gate to be set off more easily and more consistently. We also modified the way in which the fly weights collided with the gate mechanism to release the balls. Moving gate paddle away from the fly weights allowed for a more responsive contact. The only other significant issue we had was triggering the next team s device. Team two s device ended and started on the same side. This would have necessitated our devise to be in the same place as team three s device. In order to allow the chain to continue, we had to move our device away from team two s and set it off at an odd angle. We achieved this by adding a piece of rod to our trigger arm that would trigger their first step from a distance. Other than these minor adjustments, there were no major flaws in our design. Conclusion This project was challenging in a way that requires imagination and problem solving. We found it to be an entertaining application of physics and a good exercise of creativity, team work,

5 communication and time management. We encountered a few problems along the way, but were able to solve all of them in an efficient way. Each of the team members contributed to the completion of the project. Every member gave input to the tasks of writing the report, helping with project construction or design, problem solving, making the presentation, and presenting the device. Doing this project allowed us to apply some of the knowledge we have acquired in this course in a way that also challenges our thinking process as well as learning to work in a team.

Rube Goldberg EF 151 Project

4/26/2010 Team Number 7 Class B1 Rube Goldberg EF 151 Project John Shin Matt Dischner Jacob Price Rob Baldus Abstract: What we are trying to accomplish with our Rube Goldberg device is the ability for