Semester 2 - Blog Post #3

Over the work period March 6-26th, our team has made progress obtaining standardized parts and has begun construction of the device. PVC pipes, connectors and bearings have all been purchased. The PVC pipes that make up the structure have been cut and assembled with the connectors. The dimensions of some of the PVC pipes have been overestimated so that excess can be cut off once the important components have been drilled into place. The aluminum sheet has been cut into three by seven inch squared rectangles to make up the blades of the water wheels. The 3D printed components have been made, but have not yet been assembled.

Our team has had an ongoing issue with the 3D printed parts (gears and water wheel centers). From reducing the size to simplifying the design, our team has had to send multiple requests to the UH printing lab, accompanied by long waiting periods. Due to the ongoing conflicts with the university’s 3D printing lab, we recently found a family friend who offered to print our components for free. This meant that we received the parts weeks prior to when we were expecting to. However, an old STL was accidentally sent in instead of the newest version. This mistake wasn’t caught until after both gears had been printed. The inner diameter of the gears were two inches instead of one inch. We corrected this by printing sleeves that fit into the centers to decrease the diameter to the correct size.

The above pictures are the gears with (right) and without (left) the diameter reduction sleeve

From now until April 16th, our team will finish construction of the first prototype and will test the device to ensure successful performance. An anticipated challenge we may face is with the sturdiness of the PVC frame of our structure. Some of the parts are considered to be heavy, such as the belt and the water wheels, which may affect the strength of the frame. Depending on how much the weight affects the frame, our team will reinforce the frame by placing excess PVC pipes between joints and edges to stabilize the structure. Another challenge our team may face is with the connections between the bearings and the axles. Based on the dimensions, it is expected to fit in place. However, in the case that the bearings have any manufacturing errors, such as inaccurate inner diameters, our plan is to purchase bigger bearings and fill in any excessive space between the axle and bearing with expanding waterproof glue. Lastly, our team is concerned over any water leakage into the structure between components. Our solution to find areas of leakage is to submerge the device in water and observe any points where air bubbles form. Once the areas of leakage are found, our team will use the same waterproof glue to fill those areas to completely seal the device from any potential water entering.