The history of our project
The final design of our turbine was almost entirely made possible by trial and error. Along the way we've tested many different designs, prototypes, and variations to get to our final product. This includes a timeline of improvements on the blades, gears, tower, and nose cone.
Blades
Balsa Wood
When we built our first prototype of the turbine, we originally used balsa wood. We thought this was a good choice because of its light weight.
We ran many tests with these blades, adjusting the pitch and angle. Surprisingly, they performed well compared to our original 3-d printed blades. We actually used them for the regionals competition, and won.
Original 3-d printed blades
After using balsa wood, we came up with the idea to use 3-d printed blades. We used Qblade to come up with the optimal shape and design for them.
One problem we ran into however, was that the blades were too heavy, and would not spin quick enough to offset the gained energy we would get from a better shape.
We still brought them to regionals, and the judges liked the idea.
Styrofoam blades
After regionals, we went back to the drawing board. We needed something light, so we cut and experimented with styrofoam a bit.
It was with these blades that we did many tests with pitch, and amount of blades on the turbine. We also realized the greater the area of the blades, the more wind that hits it, which is a good thing.
New 3-d printed blades
We decided to 3-d print another batch of blades, this time learning from the shortcomings our previous models. This time we used a much lighter filament, and printed them hollow. This made the blades weigh drastically less. We also increased the surface area of the blades, making them bigger.
We still needed to print them in two separate parts because the size of the printer itself isn't big enough for an entire blade.
Later we added infillings to the base of the blades because they were too wobbly against the wind. These don't change the appearance on the outside, however.
Gears
Single Gearing
We started off with just a single gearing indirect drive system for our turbine. It is connected to a provided generator, and has a gear ratio of 1:8.
We ran into several minor issues with the gears as well, like the gears coming lose causing unnecessary friction. We tightened the gears and added zip-ties to solve this.
Double Gearing
We decided to try double gearing to see if it would yield a larger power output. It took a while to fit the gears together and build the added level to accommodate the extra gear.
Every new addition has its cost, and in this case, there is a lot of friction. But the extra power makes up for it, so we will be using a double gearing system.
Tower
PVC pipe
We decided to go with PVC pipe for the tower because it is cheap, quick, and easy to assemble.
Water-filled base
Although our attempt was made in vain, we tried a second base option. This included a container filled with water that in theory would keep the tower stable. This didn't work however, so we kept the PVC pipe design.
Nose Cone
3-d printed Nose Cone
The nose cone was the final touch to our turbine. While the performance difference with it was negligible, it accurately models what an industry standard nose cone would look like.