Project overview For this Reverse Engineering project, we were tasked with deconstructing an item of our choosing. My group chose a pull back toy car. The question that we asked ourselves when doing this project was: how do the subystems of this product work together to create the overall system of the car? To answer this question, we took detailed notes and sketches of the product, both as a whole and as individual parts. We had to disassemble the product down to the lowest possible parts and think about how these parts were made, how they worked or fit together with the other parts, and how they achieved their function. To create our presentation, we split the analysis into four parts: functional, structural, material, and manufacturing. Each group member specialized in one part of the analysis, and then we combined our findings together to create a clear overall picture of the project. For our main focuses we looked at the "engine" of the car and since it was fairly basic, we went as deep as we could to find the exact ways in which the car's system worked.
Our report
Purpose: For our reverse engineer we decided to break apart a toy car. It seemed like a fun way to start the year, not something to hard but also something that we all had some familiarity with. As a group we wanted to learn a little bit more about the toys that we used as little kids. We also wanted to focus on the small things that go on within a toy that we don’t normally see. Hypothesis: Our hypothesis going into this project was that we thought that the toy car ran on a spring loaded system and when released the car would unwind and the axel would rotate, propelling the car forward. Structural Analysis: The car is held together by the frame. The frame also protects the gears and inner workings of the toy. It is connected to the base of the car with small screws. The base of the car has two brackets where the axles rest. The tires of the car are designed to give the car some sort of grip to the ground so when they spin they also pull the car along. The tires are then attached to the rims and those are connected to the axle. The axle is also connected to the gears which the spring is wound around. When the spring is wound up tight, the axle is also spun, thus turning the wheels when released and moving the car. The clutch is also a very important part of the car. It allows the spring to disengage with the axel and doesn’t pull the car back as the spring releases.
Type of Plastic: Polystyrene. It’s an inexpensive synthetic aromatic hydrocarbon polymer made from the monomer styrene. Composed of individual cells of low density polystyrene, polystyrene is extraordinarily light and can support many times its own weight in water. Because its cells are not interconnected, heat cannot travel through the plastic easily, so it is a great insulator. main component is styrene (C 8 H 8 ), which is derived from petroleum or natural gas and formed by a reaction between ethylene (C 2 H 4 ) and benzene (C 6 H 6 ); benzene is produced from coal or synthesized from petroleum. Styrene is polymerized either by heat or by an initiator such as benzoyl peroxide. To form the low-density, loosely attached cells, polystyrene must first be suspended in water to form droplets. A suspension agent, such as specially precipitated barium sulfate or copolymers of acrylic and methacrylic acid and their esters (organic product formed by the reaction between of an acid and an alcohol), is then added to the water. Numerous suspension agents are used commercially. All are similarly viscous and serve to hold up the droplets, preventing them from sticking together. The beads of polystyrene produced by suspension polymerization are tiny and hard. To make them expand, special blowing agents are used, including propane, pentane, methylene chloride, and the chlorofluorocarbons. Safety: The plastics used to make this product are relatively safe because polystyrene foam contains the toxin styrene and benzene. However it goes through the water droplet process before manufacturing, which makes it harder for the toxins to released since the water droplet process makes the foam more durable and no longer form, preventing easy decomposition in heat. Also polystyrene is harmful to the environment because it takes 500 years to decompose and its production emits hydro chlorofluorocarbons into the atmosphere, further damaging the ozone layer.
Manufacturing Analysis: The pull back car made by Rongqiang may seem complicated , but it can be put together fairly simple. Combining many different types of plastics using heat to create one mold, is one of the simple ways the car is made. Specifically, styreneis the basic unit of polystyrene, which is formed by combining Ethylene and Benzene. Specifically, styreneis the basic unit of polystyrene, which is formed by combining Ethylene and Benzene. Next in making of the plastic there is heat formation which is how the plastic is molded to the shape of a car and why it is so small. With the reformation of the plastic using heat they also use this method to make the wheels and almost every part on the little toy car. Manufacturing consisted of changing and molding of small plastic particles made in the form of polystyrene. I’d also have to say that Eliza played a key role in helping our group research this, and we really owe it to her.
Concepts Reverse Engineering - method used to analyze an existing product to see how it is made, and possibly how to re-make or improve it. Invention - design work that creates something new. Innovation - improving an existing product or idea. Teardown - disassembly of a product/item for the process of reverse engineering. Functional Analysis - analysis that deals with function of different parts, how they work together, and the scientific principles that are related to these parts/how they function. Structural Analysis - analysis that deals with how the parts are supported and connected together, and the purpose of each part. Materials Analysis - analysis that answers what materials were used and why they were used. Manufacturing Analysis - analysis that determines how the product was made, how raw materials were made into the finished product.
Many facets of this project relate to other disciplines. For example, human factors and ergonomics play a large role in reverse engineering because we must analyze why certain design decisions were made for human products. For example, the pot for our product fits easily in the average palm. A bigger design, while it could hold more, might not be as good ergonomically. Another area that connects with this engineering project is physics, which helped us explain the electrical circuit in our product. This was an integral part of the functional analysis. Lastly, we used a lot of English skills and concepts to write our report after we finished our analysis.
Review of project: This project was a pretty successful 1st project for our senior year, we were introduced to a whole new set of concepts and materials and were thrown right into the fire. It took a while to finish but eventually we were able to put together a finished report and presentation. Our group worked well together even though we were a little crunched for time there at the end. One peak that we had was when we were finally able to crack open our car and get an actual glimpse at what we were dealin with. Another high point for us was the delivery of our presetation to the class. Even without a group member we were able to convey the information we wanted. The lowest point for us as a group was when we lost Rachael for about half the project. She had a concussion during water polo and never came back, this was especially rough because she was the one with our object and the pictures of it. Another rough spot was when we realized that we were going to have to scrap our initial plan of doing a poster because of a time crunch. Something new I learned about myself was that if I am to succeed in this class I need to be on top of my work when I’m at home looking at google classroom. This is the first class that has really used it as a major tool for the class. Through and through this was a good starter project to get us in the flow of the senior year. I look forward to the project to come this year.