Post on 08-Jul-2020
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.