Post #5: Winter and Spring Semester Update

This blog covers the progress from the period of Dec. 1, 2020 - Feb. 5, 2021. During this period our team located and ordered most components, changed our roundabout design slightly, met with our university machinist to discuss our design, and are currently testing our generator. Components we have managed to acquire or order include

- Aluminum bars for handrails

- Metal sheet for handrail bases

- Turntable bearing

- Bases for the rotating and static platform

- Sprockets and chain

- Generator with diodes and capacitors

Our original roundabout design used gears to transfer motion from the rotating platform to the generator shaft, but after communication issues with the vendor and price constraints, we decided to switch to using sprockets and a chain instead. This is not an issue and is actually beneficial for us because not only is this configuration much cheaper, but we also obtained a higher gear ratio of 48:8 for a ratio of 6. We also decreased the scale of our center shaft in order to save money. We connected with the machinist a couple times to review our design and confirm our parts with him. The machinist recommended us McMaster as a vendor for parts which is where we are ordering our metals, sprockets, and chain from. Figures 1 and 2 below show our current CAD model which the machinist reviewed and said there shouldn't be any troubles constructing.

Figure 1: Top view of the roundabout.

Figure 2: Side view of the roundabout.

For the work period Feb. 3 to Feb. 19, we will be conducting tests on our generator to get an idea of how much power it might be able to output. Our current circuitry has two diode bridge rectifiers, which are in parallel with capacitors, in series to convert the AC to DC. Preliminary testing shows that we can get up to 25V and 0.4A of current which translates to about 10W of power, but we are currently researching to see if our circuit can be improved. The machinist said he would not be able to start working on our project until a date range of Feb. 22 to March 1, which gives ample time to pick up wood and fasteners for the rest of our build.