For this project we where assigned to take the concepts of reverse engineering and apply them to an everyday product. Reverse Engendering is the concept of taking a already made product, strip it down, then fix problrms in the product of make the product better in some way. For this project we choose to apply the concepts of reverse engineering to a small desk fan. We took it apart figured out how it worked, then thought of ways we could make it better.
Presentation
Report/Content
Purpose: We started this project with the intention of learning how our product works. We have achieved this through research and the process of reverse engineering.
Device Description: Our device is a basic table fan. It has 18 pieces, most of which are screws. Its main parts are the blades and cage, motor and casing, usb cable, and stand. It uses convection to displace heat by blowing room-temperature air into the place of warm air surrounding an object, allowing the object to transfer more of its heat to the fresh air.
Structural analysis: The fan has many interacting parts that all rely on each other for the fan to properly function. The first part of that fan I will analyze is the outside metal casing and support structure of the fan. The fan is held up by a metal pole that is curved to hold up the fan. This piece also has three rubber stoppers that help the fan gain traction on whatever surface it is on. Lastly the pole has two holes on both sides and their purpose is to attach the fan to the metal casing. The metal casing is two pieces of cage like metal that scround the fan blade as well as the motor. The front of the metal cage is fully inclosed, and the back has an opening that fits the motor. Both the sides of the cage has holes in them so they can screw into each other. Next is the motor. The motors source of power comes from a USB outlet. Then the electricity from the USB travels up two wires, where it meets a switch which determines if the electricity will travel to the motor. The motor is composed in copper wire that is an electromagnet. On the outside of the electromagnets there are normal magnets that hold the fan in place when the fan is off. Next is a magnet that is encased by plastic, this is what the fan is attached to and the magnets make the fan spin. This piece was attached by a metal piece that slides into the main motor of the fan. Lastly the fan is made out of a piece of aluminum is curved at the four corners in order to push air. The fan also has four holes in the middle and their purpose is to make it so the fan can screw onto the motor. Material Analysis: The fan is mainly made of three materials: plastic for the motor casing, metal for the fan, blade cage, motor, wires, screws, and USB, and rubber for the wire casing. The plastic was most likely used for its low price and functionality. It serves a simple purpose: it encases the motor and protects it from dust and damage. The metal was used for its durability and strength, as well as its electrical properties. It serves many purposes, mainly to withstand the pressure of internal and external forces, but also to conduct electricity. This fan design could have its plastic materials swapped for more durable metal materials, but swapping the metal materials for others would not allow the fan to function. The rubber was chosen because it doesn’t conduct electricity and therefore protects the user from being electrically shocked when touching the usb cord containing wires. It was also probably chosen for its flexibility, because the cord needs to be flexible for the fan to be practically plugged in to different sources of power. There are 11 screws for attaching the pieces, 2 halves to the fan cage for protecting the blades, 1 set of blades for pushing air, 1 motor for spinning the blades, 1 motor casing for protecting the motor, 1 usb cable for sourcing the power, and 1 stand for directing the wind. Model Code: ME6604-BR Power Type and Requirement: DC 5V 3W Manufacturing Date: 2013.03
Manufacturing Analysis: For the plastic casing around the battery and motor, it is most likely created by the melting of the plastic into a mold that was laser cut by a computer program. The wires are made by drawing out a conductive metal that is then coated in an insulator. The metal blade cage along with the stand are most likely made by injection molding, which is a process that injects molten metal into a mold. The coils are just a conductive material wrapped around metal into a coil shape to better conduct electricity. Functional Analysis: Motor: To make the motor spin, electricity must pass through the copper coils inside the motor. When electricity is allowed to flow through the circuit when the switch is flipped on, it creates a magnetic field in the copper. This magnetic field then causes the magnet that rests on top of it to spin, and that causes the fan blade to spin (Src: edisontechcenter.org). Fan: Fans push air depending on the angle of the fan blade and the direction the fan is spinning. If the blade is pointed upward in the direction it is spinning, then it pushes air down, creating a downdraft. Reversing the direction would make it push air up, creating an updraft. While the overall design of the fan may seem simple, it is a complex creation of many big and small parts. There are three main ways that these parts could be changed to improve the functionality of the fan. The first change could be an increase in electricity flow allowed through the circuit. This increase would make the motor move faster by allowing more electricity into the electromagnet, causing it to create a stronger magnetic field. Similarly, the second change could be in the magnet that rests on the motor. Increasing the strength of the magnet makes the fan spin with greater speed because, while it may take a bit longer to start spinning, it will stay spinning for longer and the heavier magnet will be able to spin faster. The final change would be to the amount of copper coiled inside the motor. The more copper there is, the bigger and stronger the magnetic field it creates would be, causing the fan to spin faster.
Reflection
With this being the first project in my new senior engineering class, there was a lot that I learned. This class has a lot of freedom with time and little structure on how you get your work done. This can be beneficial because I felt like my group did a good job as assigning the tasks that needed to be done, as well as spreading out the work evenly. Every member of our team got their assignments done on time, and we all could rely on each other. Although the freedom was beneficial in some ways, in other ways there was still a learning curve that we need to get over. Although we got our work done on time we had overlapping projects and managing them all became difficult. Closing in near the deadlines our work became stressed and rushed. Secondly this class is extremely detail oriented. This helped us when making sketches that where nice, as well as including all our information in our report. Although we had a lot of detail in out project and we knew quite a bit about fans, out knowledge could have been better demonstrated thought the presentation and the report.