Mission Statement: Our goal is to provide safe, efficient, sustainable, and easy-to-use energy to all aspects of the rock crusher project.
We considered a variety of energy inputs from solar power, to human power, to vehicle power, looking at
the specific needs of the client and the availability of resources to pick the best paradigms. By assigning quantifiable metrics to the needs of the women in Uganda we were able to objectively rate the different power sources on their usefulness for the project. The top three power paradigms all ended up being human-powered because of the initial cost of each design, availability of materials, and costs associated with the sources.
Final Design Paradigms
Bicycle-Powered: Harnessing the power of your average bicycle.
Used bicycles are readily available in Uganda and could be used for day-to-day transportation on top of providing power to our rock crusher. Power can be provided for hours using this method and can be easily used by people regardless of where the machine is. The only negative aspect of this paradigm is that the bike will output less power than our other paradigms.
Capstan-Powered: A type of winch usually used on ships to hoist anchors.
This simple design is highly could be adapted to run on the power of as many people as desired and
could easily be modified to provide the optimum amount of torque. However, this device does depend on good traction to produce power and is very bulky compared to other paradigms.
Decision, Implementation, and Integration
The bicycle power was best of our paradigms with the availability of parts and multitude of uses clearly beating out our other paradigms in the House of Quality analysis, despite its relatively lower power We also liked this option because of its ease of integration with the other teams like transportation and rock crusher, and its wide availability in Mukono, Uganda, where the rock crusher will be. This paradigm perfectly captures the goal of the team with an emphasis on sustainability and ease of use.
To develop the prototype of the the rock crusher power input at WSU we began by acquiring two bikes from a local bike shop, B&L Bicycles, both at $80 (265k Ugandan shillings), and a bike stand from Amazon.com at $14 (46.5k Ugandan shillings). With the stand supporting the back wheels of the first bike we were able to disassemble one of the bikes and takes its chain and sprockets to connect the back wheel of the bike shaft needed to power the jaw crusher. While the jaw crusher has not yet been acquired, a shaft will project from the flywheel and be attached to a sprocket (acquired from the disassembled bike), that will have a bike chain running from it to one of the bike’s gears. This is pictured on the right.
For the integration into the overall system, the bicycle will be run on a stand and transfer rotation from its back sprockets to a shaft that will give rotational energy to gears running the rock crusher team’s jaw crusher. When the device is not running the bike can be attached to the transportation team’s cart to move the rock crusher to where it is needed.
In conclusion, we concluded that bicycle power would be the best way to power the rock crusher machine. If we were to continue work on this project, we would work to establish a more sustainable source of cheaper bikes, like through a partnership with an NGO. We would also attach the shaft to the sprocket.We made a CAD model (left) to illustrate our system. With this system, we think the Ugandan women could easily and sustainably operate the jaw crusher and crush rocks.