Murlin Trebuchet Case Study

Murlin Trebuchet

SUMMARY
Murlin Tebuchets are lightweight, transportable, and very efficient.  The advantage of that is that you can fling a projectile far distances using very little counterweight.  This project is an engineering masterpiece and that is why I want to work on it.

CASE STUDY #1
Rating (7 /10)

Diagram of Murlin Trebuchet
http://www.behance.net/gallery/The-Murlin-Trebuchet/10601767

 Positives:

• It has a video, step by step
• Many, many photographs

Negatives:

• Dimensions are vague
• No specification of hardware (pulleys, bearings, release pins, firing mechanisms)
• No (Content) Most important Dimensions, weights, mass ratio and range are not given in text.
• You have to watch the video to know how to build it

http://www.behance.net/gallery/The-Murlin-Trebuchet/10601767

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CASE STUDY #2Rating (10 /10)

Diagram of Murlin Trebuchet
https://etown.digication.com/kaylee_werner/Trebuchet_Project

 

Positives:

• It has a video, step by step
• Many, many photographs
• Dimensions are vague
• Specification of hardware (pulleys, bearings, release pins, firing mechanisms)
• (Content) Most important Dimensions, weights, mass ratio and range are given in text.
• Results shown

Negatives:

• None

https://etown.digication.com/kaylee_werner/Trebuchet_Project

 

 

 

 

 

SumoBot

Sumobot

Mike Desmond

Winning bot

Our bot

Our bot

The project requirements were to build a robot vehicle that can have a brain attached to it that will be able to make it around a course in the hallways.  It had to be as fast as possible to beat other teams and had to be precisely crafted in order to maintain stability and accurate steering.  We chose to mount the motors and wheels at the end of the given wood piece, and the roller bearing wheel in the front with the brain and batteries in the middle.  This would give us the option to have either side the front, so we could experiment which was better - for the powered wheels to push the rest of the bot, or for he wheels to pull the rest along.  Groups 1 and 2 finished, but not groups 3, 4, and 5.  Group 1 was 2:24 and group 2 was 2:50.  The overall winning bot was very fast because it had a wide wheelbase, was assembled carefully, and had a great gear system.  Unfortunately, our group's bot was unable to make it around the track since it couldn't go very fast, and couldn't go straight or left because it kept going right.  What I would do to improve this would be to get smaller wheels, maybe add a gear system, and possibly make the rear wider so that the weight can be placed on the wheels.

Fastener

Art Structure

Mike Desmond

 

Rubber Band Fastener

Our groups design

Our fastener was the rubber band.  We designed and layed out the structure with the pieces, and then designed how we would connect and hold everything together.  We made up a system where we cut grooves in the sides of the wood where the rubber bands would hold, so that they would stay in place.  The rubber bands would hold the pieces of wood together, and the rubber bands would be held in place by the grooves.  When we noticed weak spots, we added more rubber bands to increase the strength and hold the structure together more securely.  Sean's idea was to make a field goal post, so we designed it.  We experimented with the structure so that it could be held together in the most secure way, and finished pretty quickly.  We could've worked more to make it more advanced but had no more ideas and the rubber bands limited our creations.

Build a Compound Machine

Build a Compound Machine

Mike Desmond

 

Our machine that we built

We combined and transformed our four simple machines to create a massive machine that would give us the ultimate mechanical advantage.  We put the lever on top of the pulley frame so that we could attach the wheel and axle to pull down the lever.  At first, the pulley system did not do anything.  But then, we incorporated the pulley system by having the string pull down the pulley, and secured the second pulley to the bottom of the base.

The project turned out great and we were in the lead.  Other groups followed our idea of this and took the ideas themselves.  The string was falling off of the wheels so we added another axle to correct this and guide the string to go straight onto the wheels.  We also extended the arm of the wheel and axle multiple times.  Our methods were very successful and it turned out to work perfectly.  We achieved the highest mechanical advantage in the class.

We learned that it would be easier to plan it all out in the beginning so that we can modify all of the parts before-hand instead of having to take apart many things.  There were no surprises in this project.   I could definetely use this knowledge for future projects.  I found it very easy and creative to build simple items, like our four simple machines, and then combine them to make something very cool.  This machine turned into a piece of art and it was a pleasure making it.

Simple Machines

Four Simple Machines

Mike Desmond

 

 

We built a lever, wheel and axle, and inclined plane, to a mechanical advantage of 6, so that we could demonstrate how much they help us to make everyday work easier.  The pulley that we designed had to have a mechanical advantage of 2.  To calculate the % efficiency we did the Actual Mechanical Advantage divided by the Ideal Mechanical Advantage, and then multiplied by 100.

                            Lever by our group                                 Inclined Plane by our group


Pulley by our group

Wheel and Axle by our group



 

 For the Wheel and Axle, we tied for third place, with about 70% efficiency.  For the Inclined Plane, we came in 5th with 33.33%.  On the Lever we had a 66.67% efficiency, which made us come in second because everyone else was diqualified.  On the pulley we had 64.79% efficiency, which landed us last place, but when Mr. Adkins measured everyone's projects to see if their measurements were off, and many groups except ours exceeded the qualifications so they were considered cheating.  That was what also made it difficult to determine the placement of the teams, because you have to tell if the machine was built correctly and was within the guidelines.

We were pretty far from 100% efficiency each time.  This was because our measurements weren't precise enough and we didn't have the most precise tools to be able to build a machine that well.  Another reason is because we did not factor in friction with this.  One more reason why we didn't achieve 100% efficiency was because testing the machines was difficult and not accurate at all.  Unfortunately, there was really no better way to test our designs.  If we made our machines on a bigger scale it would've been easier to be more precise, but that would've also taken up more time and costs for the larger materials.

 

 

 

 

 

 

 

 

 

 

 

 





Reducing Six Simple Machines to Four

Reducing Six Simple Machines to Four

• Pulley
• Wheel and axle
• Lever
• Wedge
• Screw
• Inclined plane

How we can reduce to four:

There is no need for a wedge, since we already have an inclined plane which is basically the same thing, and we don't need a wheel and axle since the pulley includes that. The screw is just an inclined plane wrapped around a point.

Mike Desmond
Brainstorm

Project Ideas:
Use an Emotiv to control typing on a computer so it would be much faster
Use an Arduino TRE to detect snow on the roof of a car and turn on a heater to melt it.
Use an Arduino TRE to detect a breeze when someone walks in a room to turn on the lights
Use an Emotiv to open your lock when you are near
Use an Arduino to sense when there is an increase in sawdust and turn on the vacuum fan

Class Trip

Mike Desmond

 Class Field Trip

 

In our Applied Engineering class, Mr. Adkins is letting us choose where we would want to go on a field trip.  I think we should go to Six Flags.  Six Flags would be a great trip for this engineering class because it is a fun place and the whole park is based off of amazing engineering possibilities.  This should take place in the spring, like in april or may.  This is within a reasonable time to get there, which would maximize time at the site.

 

One possible idea is to contact the Six Flags engineers and have them give us a tour and teach us about how these rollercoasters are possible to build, and what makes them so fun.  Everyone would enjoy the rides, and no matter what ride you are going on, there was a ton of engineering put into it that makes them work, and this would teach us a lot about the real-world engineering jobs and what they have to do.

 

This link shows how Six Flags is a combination of Science, Physics, and Engineering:

http://hub.jhu.edu/gazette/2012/december/biomedical-engineering-roller-coaster-research

Westwood on the Cutting Edge

Westwood on the Cutting Edge

Mike Desmond

 

It is coiled heating wires on the roof of a car that will heat snow off of the roof in the winter and prevent accidents.  This will come in handy in northern areas and Canada.  It uses an Emotiv to sense the environment to sense snow and turn on the heaters.
People will learn math, science, and physics from this project.  They will learn how an emotiv works because the emotiv will sense the temperature outside and turn on the coils to heat the outer shell of the car, which will melt the ice and snow.  When the car turns on, the emotiv will automatically detect the temperature of the environment, and detect if their is any weight on the roof of the car and will activate the heating coils.

 

Design Cycle Notecard Challenge

Mike Desmond

Mr. Adkins performing the "Adkins A"                 How the structures collapsed.

For this challenge we had to design a structure to hold as much weight as possible.  The design needed to be out of a notecard, and 4 inches of tape.  It had to hold the weight at least an inch above the ground.  Most people rolled the paper tightly and used it as columns to support either the books, the weights, or Mr. Adkins.

On our first attempt we took the whole notecard and rolled it horizontally to make one column to support the weight.  This failed horribly and did not support much weight.  When we observed other people attempting this project, we found out that it was more helpful to use multiple skinny columns rather than fewer wider columns.  These were more sturdy and stable and resisted crushing better.  Another thing we experimented was the placement of the columns.  We started with placing them all in the middle, to placing them at the extents of the weights.  With all of this, we were able to design a structure that got us to hold over 200 lbs.

A design that failed 

Innovation: Facebook

 

Facebook

 

Created by Mark Zuckerberg - 2007 - Facebook

 

 

Before Facebook, MySpace was another form of social media, but not everyone used it.  Facebook was created as a very easy application to use, so that you could interact and see what's going on with people you know.  It made society a little closer together as know it is easier to see what other people are up to.

This transformed society into an interconnected web.  Everyone knows what everyone else is doing and a complete stranger can track your every move.  But, you can catch up with your family members across the globe!



Invention: Penicillin

 

Penicillin

Alexander Fleming - discovered in 1928 - called it Penicillin

 

 Before the discovery of penicillin, life was rough.  Many people had lived short lives.  There was no true medicine for the illnesses people had.  When penicillin came around, everyone's lives became healthier.  The expected live span around the world jumped.  There was now medicine!  It could now cure many infections.

This discovery now boosted life for humans.  We can now live longer and not have to worry as much when we get sick, as we have penicillin.  This discovery also led to many other advances in medicine.  These other advances are helping us live a healthy long life.  The world as we knew it became a healthier place.

Maker Faire