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.