OVERVIEW: The purpose of this project was to design and build a Rube-Goldberg stamper device that could place a stamp anywhere on a 5 inch by 8 inch piece of paper. The device had to be inefficient and complicated, as well as original. The entire device had to be able to fit within a 0.3 meter by 0.5 meter by 0.3 meter box when started. The stamp had to be a maximum of 3.0 centimeters by 3.0 centimeters in size. Also, the device had to operate without interaction once it was started, and it had to include examples of projectile motion, conservation of energy, and conservation of momentum. Lastly, the device had to be operated in a safe, clean, and nondestructive manner. DESIGN PROCESS: Our design process for this project consisted of several group meetings in which all members of the group were present and many ideas were formed. In the first group meeting we compiled everyone s ideas and decided as a group which design would be the best one. We came up with a lot of different ideas, but a lot of them were not used because many of them were not going to work. In the compilation of our ideas, we decided that there were some criteria that we did not want to include in our design. These criteria included a Newton s cradle, a pulley system, toy gun, razor blades, and pool balls. These were not included in our final project because we wanted something that would work every time and did not have many variables. Another reason we didn t put some of these in our project was due to the size of the objects. Many of the objects were too big to fit onto a.5x.3 meter board. Pool balls and a Newton s cradle would have been pretty neat to see go onto a project like this, but they seemed kind of big in comparison to the rest of the project. Description of Project Our project was built out of scrap wood, duct tape, nails, glue, a cup, golf balls, close hangers, a mousetrap, and fishing weights. The first thing that we did is cut a piece of plywood to the size specifications that were given to us. We then proceeded to cut smaller pieces of plywood for the ramp, the starting piece, and the see-saw arm. The starting piece and the ramp were nailed together in the shape of a v so that the golf ball would have a nice groove to stay in. The arm for the see-saw was just a strip of wood 8 cm long. We used two 2X4 s for the support beams and cut a notch in them so that the plywood pieces would sit nicely in them. The close hangers were used in making the ramp and for an extension of the arm. They were glued onto the wood with the gorilla glue so they were defiantly not going anywhere. The fishing weights were put in the cup and stuck on the end of the see-saw s arm. The cup was set on the other end of the see-saw and used to counter-balance the other weight. The mousetrap was then nailed underneath the end of the see-saws arm so that when the arm dropped, the mousetrap would go off. The mousetrap was also modified in that the arm was extended so that the stamp would
smack down on the paper. The arm extensions consisted of close hangers and duct tape. The stamp was then drilled into and the coat hangers were stuck through the holes.
Analysis of Stored Energy Our device starts with the conservation of momentum between the golf balls (collisions).
Next, there is conservation of energy as the ball on the end is pushed off the platform and down the ramp. Then there is the projectile motion as the ball is launched from the ramp and into the side of the cup.
The next step in which energy is conserved occurs when the cup is knocked off the seesaw and the counterweights attached to the see-saw fall onto the center of the mousetrap.
Bill of Materials person who gets it materials required materials list max price miles cup, stamp very cheap small cup $0.10 jeff coat hangers, mouse trap $4.00 Aaren gorilla glue, fishing weights, mouse trap coat hangers $1.00 chad golf balls, scrap wood scrap wood/cardboard $2.00 golf ball $0.25 stamp $1.00 gorilla glue $2.00 fishing weights $3.00 nails $0.25 screws $0.50 total $14.10 Conclusion In conclusion, our device was consistently successful in stamping an 8X5 piece of paper every time. Our device was somewhat simple, but very reliable. Every time we set the device up, everything ran smoothly. Since there are not too many extreme variables, the device will run the same every time. The time we put into this device was around 4 hours planning and around 6 hours actually building it. One of the reasons it took so long to plan was due to the fact that every one of us had a different idea of how it should be built. We finally had to agree on something that included all of our ideas into one project and came out with Big Blue. Another trouble we ran into with our project was how to make the whole see-saw deal work properly. We finally got that after some brainstorming and some luck. This was a great way to include a bunch of different material into one big thing. Overall, we thought that this was a very useful and fun project to do. It also helped to get everyone to know each other a little better too. One last thing that I would like to comment on is the size of the project. I wished the size dimensions were a little bigger. This would really bring out some creative projects if the there were no size constraints to deal with. This would also probably make it harder to judge one project against another.