Compound Machine Project Designers Vinicius Fernandes Nathan Abraha

Compound Machine Project Designers: Vinicius Fernandes, Nathan Abraha, Amber Jackson

Step 1: Identifying The Problem Our team has been tasked to lift a bucket one foot off the ground by building a compound machine that has a mechanical advantage of at least 5.

Step 2: Generating Concepts We came up with three possible ideas for our machine.

Step 3: Developing a Solution We decided to use Idea #1 in the build. We decided to use this idea because it would be the simplest to build.

Step 4: Constructing and Testing Prototypes While constructing we came across many obstacles such as: Our initial design wouldn't lift the bucket We lost mechanical advantage Our machine wasn't very efficient So we decided to completely change our prototype.

Step 4 (cont. ): New Design We moved the wheel and axle to be level with the pulley and also moved the pulley to be above the lever to provide more MA.

Mechanism 1: Wheel & Axle IMA = De/Dr IMA= 10. 4/8. 4 IMA= 1. 2 Initial Effort Force

Mechanism 2: Chain & Sprocket Gear Ratio= 1

Mechanism 3: Wheel & Axle IMA = De/Dr IMA= 8. 4/1. 9 IMA= 4. 42

Mechanism 4: Pulley System IMA= 4. 00 4 opposing strands

Mechanism 5: Second Class Lever IMA = De/Dr IMA= 4. 45/25 IMA= 1. 8 Resistance Force Effort Force

Step 5: Evaluation Our Overall IMA was 37. 8 but our AMA turned out to be 12 which is an efficiency of 32%. We lost efficiency because the pulley system didn’t have 4 directly opposing strands. If we were to improve it we would remove the second class lever. We would also improve the speed of the machine by adding a compound gear train.