Floating Arm Trebuchet Case Studies

Chris Geimke                                                                                                                                 5/9/14

Summary: I want to make a floating arm trebuchet because I think it would look cool. It also has a better efficiency than the counterweight trebuchet. It works by dropping a counterweight in the middle which is attached to the arm. A wheel is attached to the arm to roll across the machine which keeps the counterweight from falling and destroying the machine. the arm launches the sling which lets go of the projectile firing it into the air. It is unique because the arm is not attached to the pivot point on a fixed point.

CASE STUDY 1:

Positive Points:

•  Many different ratios for arm length
• Has lengths and dimensions
• good size to build

Negative Points:

• He is still making tweaks to it
• Took 2 months to build
• trouble making diagonal 2 x 6s attach to shannel

"The first good throw was about 206 feet, although the trajectory was way too steep, to the point where we could not see the baseball. So, I'm guessing that a baseball would go in excess of 300 feet!"

 

http://www.instructables.com/id/Floating-Arm-Trebuchet-F2K/



Diagonal support

CASE STUDY 2:
positive points:

• includes material list
• includes dimensions and angle measures
• step-by-step directions

Negative points:

• Includes welding
• dangerous machine (may fire backwards)
• used concrete and other expensive materials

Our design required that we load each weight one at a time onto the weight bar using ladders. This was done with the safety bars in place, as well as the chain clicked into the trigger. at this point, we used a ratchet to tighten the eye bolt, until the chain was in tension and the weight bar no longer made contact with the safety bars. Then, we cleared away and removed the safety bars, and fired. The chain was then loosened again, the weights removed, and the arm cocked and locked with the safety bars again, and the cycle repeats.
 

Bending Brace

 

 

http://www.instructables.com/id/Floating-Arm-Trebuchet/?ALLSTEPS

Sumobot Racer

In this project, the sumobot racers, we had to create a car that could go faster around the theater and get the best time. We had a kit that gave us variouse parts we could use to make our car have a gear-drive system or a direct-drive system. We also were able to bring in any extra parts for the front wheel. The requirements were that we had to make a car that could make it all the way around the theater and complete the course. Our design choice was to use a gear system for speed. we also pur the front wheel at the very front of the car. we thought it would help the car turn faster if it was up front.

 

 

Our project, Ronald, placed third. RDJ placed first, John Deer in second, and ASAP Fury and Bloody Mary in fourth and fifth. In the time trials, we had to make a fix while racing, which added 20 seconds. We got a time of 2:24.

Based on our observation and research, I would have made the car with a direct-drive system. We would have to worry less about the wheels being perfectly aligned. I would have also put the front wheel closer to the center to turn better, unlike our original design. I would have also used a different front wheel. The one we used didnt work too well because it slid instead of turning.

Illusion Machine Project

the purpose of this project was to see who could create a machine that could create an illusion. the main objective was to create a machine that could do this based off of the research we did in class previously. we could use any resources in the class that we could find. we had to brainstorm ideas for what we were going to build. we could have made spinning tops, yo-yos, or any illusion we could make from a machine.
Me and my group mate, Jack, made a windmill-type idea that would have small propellers on it that would spin when the main piece spins. the results were that it wasn't finished but it worked in the opposite way it was supposed to. the propellers spun clockwise when the main piece spun clockwise. our goal was for the propellers to spin counter-clockwise.
we could have made it better by picking better resources to use for the propellers.

Build A Compound Machine

In this project, we made a compound machine out of our past simple machines that we made. The goal was to get the highest AMA as possible when lifting a box of nails. We used three out of the four simple machines to build it. we did it to see who could come up with the best machine that could get the highest actual mechanical advantage.


Our machine worked well. In my group, our compound machine was the best in the class. when we measured, there was little force used to lift the box of nails. I found it hard to use the pulley to get a good mechanical advantage from that because it was hard to have it move when it was attached to the other machines. to fix this we made the moving wheel of the pulley attached to the string which lifted the lever. our methods were successful. we could have made a third wheel on the pulley to make it even more affective.


I learned that to get the highest mechanical advantage, we had to use all of the machines to get the mechanical advantage from them. the most difficult concept to grasp was how to connect them in order to perform one task of lifting the nails using barely any force. Nothing really surprised me during this project. I could use this knowledge in future projects when I need to make two different things perform a similar task.