The design cycle was utilized many times during the design and building process of my PBL project. For example, when we first chose our project idea (the Magnetic Launcher), we found that we did not have the materials that were shown online to build the project as it required metal tubes. Thus, we decided to gather more information on the characteristics of that part so we could possibly find an alternative for it. Through this research process, we found that the shape of the rails did not necessarily have to be cylindrical but could be a thin rectangular prism, which was more practical to find in our case. Furthermore, we also noticed that the original design required gold for its conductivity, but obviously our budget could not accommodate that kind of expense. As a result, we did some research regarding the conductivity of metals, and found that aluminum ranked 4th highest after gold. Therefore, we decided to purchase two aluminium rectangular prisms to substitute as the gold cylinders for the rails. Another example of us using the design process was the process of us trying to replace the spring loaded lever that we were unable to acquire. This was also partly the same issue we faced for the aluminium rails in my first example. The problem was that we needed a device to provide the initial velocity of the projectile so that it would not fuse to the rails. Thus, after our research, we considered a few ideas: 1. Flicking the projectile with fingers (too dangerous due to high voltages), 2. Shooting it with a rubber band (too inaccurate), and 3. Using a compressed air can to blow at the projectile. Ultimately, at the end, we chose to use the compressed air can because: 1. It was accurate, 2. Non-dangerous, 3. Very powerful, and 4. It is what real magnetic launchers use.
PBL Standard 2 Post
More will be added shortly….consolidating photos and information for this blog post…
Initial design ideas
Tests and Results:
(above) Tables showing data from various tests with different power sources for each test.
Communication of Results and Data:
PBL Energy Build Plan (24-26 February, 2015)
Below is the plan for Jeffrey and Tianjiu’s PBL Energy project (magnetic launcher), encompassing the days of 24-26 February, 2015.
Tuesday (24 Feb) – Start working on small scale model of our actual project. This model is a sheet of cardboard, with two aluminum sheets glued on top to simulate rails. Originally, we were going to use a battery to simulate the capacitors on the small model, but we decided that a power pack would do the job more efficiently.
Wednesday (25 Feb) – Wait for the part to arrive as the sellers don’t ship on Chinese New Year. These parts are essential to our project and we will continue to observe our smaller model to accurately learn about the mechanics of the bigger plan.
Thursday (26 Feb) – Hopefully some parts would have arrived by this day so that we could begin building our project. However, we will still continue to observe our smaller model and use the information that was gathered to compare to our actual model.
Tianjiu’s Beakman Motor
Information about the motor:
When energy is fed through the paper clips, it creates a magnetic field. When this is used with the magnet on the cup, it allows the motor to spin(generate torque). A motor is a device that converts electrical energy into movement energy.
Ryan, Michael, and Tianjiu’s Rube Goldberg Machine
This project really tested not only my patience, but also everyone in my group. We were extremely frustrated, and almost reached a point where we gave up as the design kept on getting knocked over. But as everyone finished around us, we gained a surge of motivation to finish and perfect our project. At the beginning, we examined the different kinds energies that we could harness. For example, we looked at various Rube Goldberg videos for inspiration and we felt that thermal energy would be a novel way to show thought and the design process. In order to do this, we used string as the potential chemical energy as a conduit to burn the balloon. When fire is exposed to the balloon, it will cause melting of balloon membrane, and once it burns through, it will cause a catastrophic failure in the membrane which pops the balloon. (Popping is enabled by the potential elastic energy in the balloon.) Once the balloon pops, the water is released and harnesses gravitational potential energy to fall and make contact with the dominoes. This, in turn, causes the chain of dominoes to fall upon one another, again using gravitational energy. At the end of the chain, the domino hits the marble and pushes it down the ramp. The marble currently has kinetic energy, which enables it to hit the pivot which pushes the car down the secondary ramp.
I love science!
Look, I have a new blog!