Emily Buckman

David Nguyen

Adam Tupis

Overview:

The main goal of the team was to use conservation of momentum, conservation of

energy, and projectile motion to create a stamping machine. Our secondary goal was to have as

much fun as possible while trying to build our machine. Both goals were accomplished within a

timely manner. To complete the first task we used various materials acquired from different

sources. We spent around five and a half hours building the machine and roughly four hours

conceptualizing our idea and buying the materials. During our presentation we successfully ran

our device twice.

Design:

We met once for about an hour and a half during our design process. This phase was

completely collaborative. Each person brought ideas to the table, and when we met, we basically

bounced ideas off of each other. We started with a simple design, and after troubleshooting it,

something more complicated arose. For instance, when we decided on using a guillotine, we had

to come up with a trigger for it. In the end, we took bits and pieces of each others’ ideas and

decided on our final design. While we were designing our device, we tried to use methods that

would be more predictable. We pretty much discarded any idea that we thought would give us

too much trouble. We decided against releasing a rubber band to stamp the paper and twisting a

rubber band to release the stamping-arm. Conceptualizing the device was an easy process for us;

our group worked really well together in this phase. We took each idea into consideration, and

there was never any arguing.

Device Description:

Our device has six steps. First, we pull back a fishing weight and release it. The fishing

weight hits a marble and knocks it down the ramp. As it flies down the ramp, the marble is

launched into a tube; it travels down the tube and hits a washer off of a nail. When the washer

flies off the nail, it releases the blade of the guillotine. The blade cuts the string that is holding up

the stamping-arm, and the arm swings down and stamps the paper. We built a platform to hang

the fishing weight; we designed the platform to be at the highest dimension possible on our

design. Then, we built a second platform under the first to hold the marble that will travel down

the ramp. In order to bend the tube, we had to cut the top part of the tube, which probably took

up most of our time. We nailed the ramp down to keep it in place and screwed a block of wood

under the ramp to keep it from moving. After building the ramp, we used trial and error to find a

good location to place the second tube. To keep the second tube in place we clamped it down

with two wooden blocks. We attached a washer to a string and set it up on a nail to use as a

trigger for the guillotine. To make the guillotine, we used two pieces of laminate flooring as the

pillars because of the tongue and groove in the wood. This allowed the blade to slide up and

down easily. When the guillotine blade falls, it releases the string that is holding up the stamping

arm.

Analysis of Energy Conservation:

Energy was stored in our device through conservation of energy, conservation of

momentum, and projectile motion. Our example of conservation of energy happens when we pull

back the fishing weight and let it go. Initially the fishing weight has gravitational potential

energy, and this is converted into kinetic energy when the weight is released. Our device has two

examples of conservation of momentum. The first happens almost immediately when the fishing

weight collides with the marble. Our second collision takes place when the marble rolls down the

tube and knocks the washer off of the nail. We needed the coefficient of restitution for our

conservation of momentum calculations. To find this, we dropped the marble onto the washer

and watched how high it bounced up; we also did this for the fishing weight and the marble. We

recorded the heights, and for the two different instances, we took the square root of the quotient

of the height the marble bounced up to and the initial height. The marble goes through projectile

motion as it rolls down the ramp and is launched into the tube. For this calculation, we plugged

our values into the trajectory equation in our calculator. We also had an amount of energy loss in

our device. We used mass as a variable in our energy loss calculations because we did not weigh

the stamping-arm and the guillotine blade before we attached them. We felt that estimating those

masses would mess up our calculations. To find the work input needed when calculating energy

loss, we used the force measurer to find the force it took to hold up the guillotine blade and the

stamping-arm.

Bill of Materials:

Conclusion:

In conclusion, our device was successful every time we demonstrated it to the class.

When working on this project we as a team learned how to compromise with each other to come

up with the best possible idea. We learned the practical side behind the concepts that were shown

to us in lecture. We also learned that sometimes even though planning is useful, plans are not

always going to be practical once the construction begins. Various problems arose when we

started building our project. Originally, we didn’t realize how small the actual dimensions of the

devise were supposed to be; so we thought that we might have to change our plans, but instead

we built the guillotine and the stamping-arm to the side of the ramp and tube. Then we had a

problem with getting the marble to go down the ramp. We eventually had to cut off some of the

top of the tube to make the ramp work. When the marble would go through projectile motion it

wouldn’t make it into the second tube every time so we decided to put a funnel on it to increase

its accuracy. The final problem we had was that the washer wouldn’t come off of the nail every

time. To fix this, we decided to file down the head of the nail until the washer would come off

smoothly every time.