#1: Define and Inquire

In this science engineering unit, we were asked to design a toy or educational device for a specific user that represents energy transfer. Me and Susana were thinking about designing a toy that is easy to use, easy understandable and reach the educational usage. 

For some reason we weren’t together at the beginning of this project, so we find ideas separately.

Susanna decided to build this thermal energy-powered fan. But she think it wouldn’t be as much fun as building the car, so she changed her mind. This entire fan may be simple to assemble, with no challenges, so she suggested it to me that we chose another design with more challenges. 

 

 

 

Rubber band car

 

I liked this idea because it is a car that is powered by energy in a rubber band. This represents potential energy in the form of elastic energy. When a car’s axle is turned, the rubber band is stretched. In addition, this idea meets our standard, easy use and have an educational use.  However, we thought this is very easy to build so we decide to let this be our prototype of the project and see if we have better idea than this.

Balloon-powered car

Then we found this balloon-powered car. We really liked this idea because it meets our standards, and it is very interesting. This represents energy transfer from potential energy (stored in the balloon) transformed into kinetic energy. 

Our target audience is children aged 5-12 years old. The toy car is designed to help children develop lung capacity while learning about energy transfer.

We decided to make the ballon-powered car because it is achievable in the time we have, is safe and interesting for our target audience’s age group, and have an educational usage. 

 

#2: Develop and Plan  

Here is our drawn Model, the length of the toy car was 24cm and the width was 11.5cm.

Plan Model  

Creating this project,  we need to learn how to use a power drill because we have to perforate plastic bottles. We will ask one of the design lab teacher to teach us how to safely use it.

The materials weed need are:

  1. Balloon *1
  2. Plastic bottle *1
  3. Wooden wheel *4
  4. Thin plastic straw *2
  5. Thick plastic straw *1
  6. Wooden stick *4

 

Our plan:

lesson 1: Plan and draw model

lesson 2: Find material and start building

lesson 3: Building

Lesson 4: Building

Lesson 5: Building & testing

Lesson 6: Feedback and fixing

Lesson7: Decorating

 

#3: Create and Improve  

Different to what we planed, we finished our drawn model earlier than

we think, so we started building.

 

We found this mouthwash bottle in a recycled plastic area at school, and we thought it was just the right size so we used it as the body of our toy car. The Video is showing me I’m punching the bottle with a power drill. We decided to use wood wheels, plastic straw, wooden stick and paper straw for the car.

 

The above two image shows how our car looks like for the first lesson. After we put everything together, we realized the wheels were too small, so the undercarriage of our car was touching the ground so it couldn’t move. So we change the wheels in to bigger rubber texture wheels.

 

After changing the wheels, an other problem came out.

 

Now the wheels are bigger but its weight went up. The sticks inside will move from side to side as they go along. We asked the teacher for solution, and her advice was to fix the place next to the plastic straw so that it could catch a moving stick.

After we finished fixing, we realized the potential energy stored in the balloon might not be strong enough to move our car.

 

We then asked Mr Hussack about how can we fix the car so it can be move by the energy stored inside the balloon and he suggested we could do a testing just on the straw and the balloon and see if the balloon can move the straw first.

 

In fact he is right, there’s not enough gas in this balloon to push a plastic straw, let alone our rubber four-wheeled car. Then Mr Hussack said we could change our car into boat. We thought that was a brilliant suggestion because we don’t need to change much that we already have and the chance of succeeding is very high because in water, the air stored in the balloon can better push the product forward. So we cut the wheels off the car and replace it with two ‘wings’ that we found in the crap plastic box to help the boat better sit on water. After that,  we were still worried that the water would fill the bottle and the boat would sink to the bottom, so we found four strips of inflatable plastic, and we cut them in half and glued them to the bottom of each stick.

Boat after fixing

 

We are quit satisfied at this stage and went testing our boat.

 

After testing we found out that the balloon’s position is not in the center of the boat, so when we release it, it will spin in a circle. Also, because we don’t have big plastic straw and we wanted the air to go thought the straw quickly, so we replace the straw with paper straw. The problem with paper straw is that it softens for a while after it hits the water. So we decided to put two  popsicle stick on the top of the boat to make the balloon stable and cover the whole boat (including the paper straw) with duck tape.

Surprisingly,  after all the crushing failures, we still have one class left. We decided to decorate our boar so it doesn’t look like a duck tape boat. We first thought we can paint the boat but then realized the paint will fall off the boat when it it the water, so we spray paint the boat. The colour we have chosen is rainbow because pride week is coming right after we finish our project to we wanted to support the LGBTQ+ community. We also added scientific symbols in white pens.

A video of us spray painting the boat.

#4: Reflect and Share 

Final Product

Explain how it works/doesn’t work using scientific terminology  

Explain the impact of this project on the environment, and the potential client/consumer/audience.  

All in all, we were successful because our battleship-like boats had successfully passed the experiment. I think our greatest success is to face the difficulties and failures of production engineering and then solve them. We also improved our skills with the drill during the process. Area we need to improve is to make more detailed plans, because we are in a very fast speed during our building process that sometimes we don’t think about some possible problems. If we have more time to improve our product, I would like to change the paper straw to plastic straw so we don’t have to use that huge amount of plastic and adding a cap on the bottle to we don’t need to worry about water getting inside.

This product have both a negative and positive impact on the environment due to the fact that it is made out of plastic but it is also made out of plastic in the reuse bin.

The final product is a boat that converts potential energy to kinetic energy. The client is required to blow air into the tube to store potential energy inside the balloon. The user must pinch the tube until they reach the water’s surface, so when the air is released from the balloon, it will push the boat.