Technical Report: Reverse Engineering

OBJECTIVE 

 Apply reverse engineering concept on a mechanical, electrical, or engineering object of our choice.  We will describe all the components and explain its operation.   

INTRODUCTION

          Reverse engineering is defined as the process by which an engineer disassembles a product to find out how it works.   This method is a useful tool that all engineers use to improve products that they have already produced.  Many companies around the world use reverse engineering concept. Companies use reverse engineering to prevent legal problems that may arise by avoiding specific methods used by their competitors.            This report discusses the process taken in applying reverse engineering to an object of our choice, which was a battery operated pencil sharpener.  We conclude our report by suggesting improvements for designing battery operated pencil sharpeners in the future.

MATERIALS

            Philips screwdriver

            Object (battery operated pencil sharpener)

            Ruler

            Caliper

            Auto CAD 2000

            MS Front Page 98

            Solid Works 98

PROCEDURES

                         1.   Obtain a battery operated pencil sharpener. (May be obtain from your local drug or office                                 supply store)

2.       Sketch the battery operated pencil sharpener as received in orthographic view (a ruler and micron meter can and should be used).  Include overall dimensions.

3.       Disassemble the device completely. (Be aware of the placing of the gears and components; we strongly suggest to keep notes/drawings of how the components fit together before you separate them) Use any tools (i.e. Philips screwdriver, etc.) as necessary.

4.       Sketch each component separately using orthographic view.  Remember to include dimensions in your drawings.

5.       Transfer the drawings you sketched in step two and four onto Auto CAD 2000/Solid Work.

6.       Analyze the expected function of each component and the desirable properties of the materials, and how both contribute to the performance of the device. 

7.       Using the data you’ve collected in step six, provide an overall operational description for the device, including explanations for its geometry (i.e. overall design, etc.)

8.       Discuss with your group any expected failure modes for the components.

PRODUCT ANALYSIS

External Components: All external components are made up of plastic because of its lightweight and durable qualities.

•  Main Unit: Used to cover and keep in place, the internal components of the sharpener.

• Battery Cover: Cover can be removed to place batteries in unit. Used to cover the batteries and prevent them from falling out.

• Receptacle Cover: Used to catch loose shavings to be disposed.
• Bottom Cover: Used to cover and secure the internal components of the sharpener.

 Internal Components: All internal components are made up of plastic and copper.  The copper is used to send a current to activate the rotation of the helical cutter.  The plastic is used to secure all internal components.

• Helical Cutter (Blade)/Case: The main component of the sharpener; used to sharpen pencils. The blade is made up of metal to be able to cut or sharpen wooden pencils. The case is made up plastic because of its lightweight and durable qualities.

• Motor/Gears: The motor is used to turn the gears, which in turn, rotates the blade enabling it sharpen pencils. The gears are made of plastic because of its lightweight and durable qualities.
• Component Case (in two parts): Used to secure the blade, motor, and gears. The case is made of plastic because of its lightweight and durable qualities.
• Triggering Device: Sends an electrical current to activate the rotation of the helical cutter (blade). The triggering device is made up of two parts: a plastic part and copper plate.

 DESIGN FLAWS

 While taking our product apart we found many flaws that can be improved. The flaws are listed as follows:

• Our product uses too much power to operate

• The overall size of the product is too large

• Our product is made with too many materials

• Only standard size pencils can be sharpened

• Does not have the option to sharpen different size pencils

• No AC adapter is available for our product

• Our product can be a hazard for small children

 IMPROVEMENTS

The following improvements can be made to future versions of this product:

• Only one battery should be needed.

• The product should be smaller for the following reasons:

1. Convenience
2. Space saver
3. Lightweight

• To be environmentally friendly recycled products should be used.
• Should have different size holes to sharpen different size pencils.
• An optional slot should be made for an AC adapter in case of no batteries.
• Should have a child proof cover made to prevent accidents.

DISCUSSION/ CONCLUSION

Questions:  Based on your disassembly and inspection, how could this device  be redesigned to:

a) Be more readily recycled?

b) Improved any or all aspects of its performance, including cost, safety, appearance, size, and weight?

Answers:

a) Redesigning our device can make it more readily recyclable. The whole device can be made so that one part is plastic and the other part is metal. The case will snap together so that it will not use any screws. We can redesign the pencil sharpener so that the case is made entirely out of plastic with room inside it to hold the motor, battery, blade, gears, wires, and screws. All moving parts will be held in a metal box that will fit inside the plastic case. When the pencil sharpener is broken, we can just take out the metal box and we can recycle both parts.

b) We can improve our pencil sharpeners by redesigning it so that it will be made out of a cheaper cost material such as using recycled plastic. We can also redesign it so that small children can’t take it apart so the blade won’t cut them.  An example would be to use plastic fasteners around the device.  For improvement in its appearance, we can design the device to be smaller by using less material to make it.  To reduce weight, we can use a single AAA battery instead of four AA batteries. This will reduce the size and weight of the pencil sharpener.  To make the device more attractive to the younger market, we can make the pencil sharpener in neon colors and themes such as cartoon characters.

OVERALL OPERATIONAL DESCRIPTION

    The device is the size that is so it can accommodate for the internal components of the pencil sharpener,  It is simple in shape, but its shape is functinoal.  The device is shaped in a way that the components fit snuggly inside the main unit, so there is no wasted space.  The slot for the pencil to go of the gears being used along with the motor. The triggering device is the main part of the pencil sharpener.  It works by completing a closed circuit to helical cutter to the motor, which activiates the cutter.  When the cutter is activiated, the pencil is sharpened.   After the pencil is removed from the slot, the circuit is no longer closed and the motor stops.  The screws and fasteners are located in areas that are very visible, so necessary repairs can be easily made.

   From working on our project we learned many things about the reverse engineering concept.  We learned that doing drawings on the computer is very difficult.   We also learned how to work as a team.   After working together for a few weeks, our group became closer as a whole.  Working on a simple object such as our pencil sharpener has helped us further understand the concept of reverse engineering.