## Introduction: Hydropower Toothbrush

When we get a cup of water, we let the water rush from the tap. It has always bothered me that the water's kinetic energy does not need to be so high when just filling a cup of water. All the water has so much kinetic energy, but the traditional method of turning it into electricity does not make sense, as there are many cases in which the water pressure is needed, for example when hand washing. In addition, electricity is an inefficient medium. So, I designed a toothbrush that functions like an electric toothbrush but is connected to the tap and uses the water's kinetic energy. The water, after passing through the toothbrush, can go to cup a where it will be used to rinse the mouth. We already use water to rinse the mouth after teeth brushing, so this eliminates the electricity used for electric toothbrushes.

Please note that this design is still a prototype, and that if you were to actually print this, a lot of post-printing processing will be needed, considering the many parts to this toothbrush.

In addition, I know that there are many ways in which this design can be more efficient. For example, the turbine is in a very weird spot. However, this is just a prototype and a model in Tinkercad, and can be revised.

## Step 1: Forming the Base

1. Group together a square tube with a cylindrical tube. You can make there two shapes by getting the shape, duplicating it, turning it into a hole, then shrinking the x and y values.
2. Add the axle onto the side of the box. To make the waterwheel, take the pointed windmill. Change the point width value to 10. Change the angle to 89 degrees. Change the number of blades to 11. Change it's thickness to 20. Finally, position the waterwheel so that it sits on the axle
3. Attach the cone metric(bevel) gears. The gears should be orientated so that it can spin the shaft(added next). The gears can be left at default, with the exception of changing the angle to 45 degrees.

## Step 2: From the Bottom to the Top

1. Attach the shaft to the bottom gear

## Step 3: The Top

1. Connect the last two gears to the shaft. The highest gear is where is brush is going to be

## Step 4: Bottom Cases

• Create the bottom case by getting two cylinders, and making the tube by placing a smaller cylinder hole inside the bigger cylinder. The height for both of these should be the same.
• Create a case for the waterwheel by taking two cylinders. Turn one cylinder into a hole, shrink it, and place it inside the other cylinder to create a hollow cylinder. Place that cylinder around the waterwheel.
• For the dome, use the half sphere. Shrink it, turn it into a hole, then group them together.

## Step 5: Top Cases

• Add a tube (cylinder with a smaller cylindrical hole in it) around the shaft
• Add the toothbrush head (Two cylinders, one hollow and one solid, so that it forms a cup-like shape
• Brushes: add thin cylinders on the toothbrush head to imitate brushes

And that's it! You've designed a toothbrush that runs on the flow of water!