Weekly Progress

Section 66 Group 2 Progress


Week 1

Alex, Aiden, Barbara, and Michael, the original four group members before the addition of Chen in Week 2, met one another. Unanimous decision when choosing Aiden as the group leader. Aiden became responsible for keeping the group updated on each individual's tasks and the deadlines to complete them. Alex contributed a wealth of expertise in machinery during group discussions. Michael supplied inexpensive materials, including an aquarium air pump, a one-way valve, and PVC tubing. The group met outside of class to observe the mechanisms of those tools and to determine the specifications of the equipment that would be used in the actual prototype. For instance, the group realized that the A/C pump being used wasn't a good fit for the machine, so Group 2 agreed to shop for a DC pump to replace the A/C pump. Each group member agreed to complete specific sections of the project proposal, which Aiden submitted prior to the Week 2 lab meeting.

Week 2

A new member, Haotian Chen, joined the group. The lab period was spent consulting with the professor and new teammate (Chen) to improve the group's strategy for powering the CPAP. Barbara and Alex used their knowledge of electromagnetism to form a rudimentary concept of two series of four AAA batteries each connected in parallel. They reasoned that the series component would add the voltages of individual batteries to one another, while the parallel component would allow the capacitances of the batteries to be summed. They also began completing the assigned Web surveys and ordering the specific supplies needed online.

Week 3

Aiden and Alex created diagrams for airflow, power flow, and pressure flow. Alex figured out the amount of batteries needed to run the pump for five hours. Aiden, Barbara, and Michael revised the design proposal. Aiden and Barbara edited the blog.

Week 4

Due to issues with Drexel's mailroom, Alex could not retrieve the DC air pump he was expecting. As a result, the period was spent determining other supplies to order, including a battery case, a pressure gauge, and Y-shaped tube joints. Teamwork evaluations were completed.

Week 5

Barbara, Haotian, and Michael worked on updating the blog. Aiden ordered a new air pump that arrived on Friday. Alex and Aiden got together on Monday to work on testing the air pressure for the new pump.

Week 6

The group created a scale to measure water pressure, successfully hooked up the motor and battery configuration, and tested water pressure with the U-shaped scale and water bottle. The inflation capability of the machine was demonstrated using a balloon designed to withstand over 20 pounds per square inch of air pressure. Alex proposed using smaller Y-channels that would fit the tubing more securely. Some members were still awaiting additional materials to ship at the end of the week.

Week 7

Using a plastic tub as a case to hold all components of the machine was agreed upon as the most economical approach. Calibrations were made on the water pressure scale, also called a manometer. The manometer was open at this stage, but it was agreed to make it closed to prevent water from spilling out.

Week 8

The manometer was closed and calibrated, and adjustments began to be made to the tubing to enhance the resolution of the manometer readings (i.e. to make the markings corresponding to pressure readings farther apart from one another). Wooden dowels were hot-glued to the tubing to fix the U-shape. The group met outside of class to discuss each member's role for the final stages of the project, particularly those pertaining to updating the blog and preparing the presentation. At that meeting, Alex confirmed the tubing was airtight and no longer leaked as it had the previous few weeks. By this point, all necessary materials had been acquired, and group members reported all purchases made toward the project to Aiden. Another set of teamwork evaluations was completed.