Description
Our task was, working in teams of two, to design and build a compound machine to accomplish a task. My team chose to do the task “Lift a weight 1 foot”.
My team member was Angel Navarro.
Our Design Constraints were:
- The applied effort force may only be provided by a single human input.
- The final design must include a minimum of three mechanisms including any of the simple machines.
- The compound machine must have an ideal mechanical advantage greater than 1.
My team member was Angel Navarro.
Our Design Constraints were:
- The applied effort force may only be provided by a single human input.
- The final design must include a minimum of three mechanisms including any of the simple machines.
- The compound machine must have an ideal mechanical advantage greater than 1.
Process
We brainstormed, and chose our three best designs.
Design #1 The first Idea had these simple machines: - Inclined Plane - Gear Train - Fixed Pulley The idea was to pull the weight up the ramp using a pulley, attached to a gear train. Design #2
The second Idea had these simple machines: -Inclined Plane -Wheel and Axle -Fixed Pulley The second idea was very similar to the first design. The weight would be pulled up a ramp by a separate pulley, pulled by a wheel and axle. Design #3
The third idea had these simple machines: -lever -fixed pulley -wheel and axel The last idea was to have a wheel and axle lower a weight onto a lever, which would push down one weight, forcing another one 1 foot in the air. |
We decided to use brainstorm number 2 for our final design, because we both agreed that it would work better than the other designs. The machine is set up by having the string tied to the weight, with the weight set at the bottom of the ramp. The string is lead over a pulley, and to a wheal and ale. The wheel and axle had the string tie to the axle. The string could be wound up around the axle by turning the wheel, which in turn would pull the string up the inclined plane by use of the pulley. The inclined plane was situated so that the weight would end up 1 foot off the ground when it was at the top of the ramp. We changed the brainstorm a bit by having the handle go straight instead of having a curve, because we couldn’t find a axle with a curve. The effort force is made by the person rotating the handle. The resistance force is made by the weight that is being pulled up the inclined plane.
Here is a link for a video of our machine in action:
žhttps://drive.google.com/file/d/0B6kL8nXggBXNQlRnOHlTa3IyWTF3VjAtcFZkekxuMEl5MnNz/view?usp=sharing
žhttps://drive.google.com/file/d/0B6kL8nXggBXNQlRnOHlTa3IyWTF3VjAtcFZkekxuMEl5MnNz/view?usp=sharing
Reflection
Through this project, we learned about how simple machines can combine to make a very effective machine. We did need to change the plans for our axle, because we couldn't find one exactly like in our sketch. I think our team worked effectively. If we had to do the machine over, I would suggest finding a way to make the string wind up more evenly; we sometimes had trouble keeping it from getting stuck under the metal while it wound up.