Reverse Engineering

Reverse Engineering is a specialized design process that starts with an existing item of technology which you are looking to make improvements on. Reverse engineering can be used on items that were made so long ago that the original designer is not available to talk to and the original design documents can't be found. Reverse engineering is also done on items that were designed and made by a competitor who would not be willing to help you understand the details of the product. In either case you are trying to understand the item of technology without direct information from the inventor, you only have the item to look at and analyze.

There are several examples of reverse engineering be used during the Cold War. The United State or Soviet Union would become aware of a new weapons system made by the other county and they would want to understand it so that they could defend against it. The details of weapons systems would be classified information so inelegance agencies would be looking for any pictures or new reports about them. The big opportunity would be when they could steal, capture, or secretively buy one of these weapons. Once they had the weapon, they could reverse engineer it. Examples would include the American U2 spy plane that was shot down by Russian and MIG figher jets that the United Stated acquired when Russian pilots defected in their plane. In these cases the purpose of reverse engineering was mainly to understand the technology, not to improve it. There were also examples where the Soviet Union acquired plans for an American bomber and the Space Shuttle after which Russian versions of these aircraft were made and flown. Their space shuttle exploded on its first test flight and they abandoned the project, but the long range bombers were use in their air force for many years.

When doing a reverse engineering project in class, the most important decision is choosing which product you will investigate. This requires thought so that you don't pick something too complicated that you won't be able to explain fully, or something too simple that doesn't make for an interesting display. You also have to consider the size of the object. If it is too big, it won't fit on the display board. If it is too small it won't be visible to your classmates when it is hanging on the wall. I always tell my students to avoid electronic products because I have not yet taught them the basics of electronics, and even then it would still be very had for a student to be able to explain how it works because electronic components are so small that thousands of them can be included in one computer chip. Since we have use the computer to model and assemble structural and mechanical objects, you should be looking for an object around 10 - 20 inches with 3 - 9 parts. It should have more than 2 moving parts and it can include a few electrical parts (switch, wire, light, buzzer, motor). The other very important consideration is that you have to have the product in your possession and it has to be something you are allowed to take apart and permanently mount on a display board. This means it should be anything you need to use and it shouldn't be too expensive. A good place to start looking might be your kitchen or garage for a hand-held or table-top tool that is old/unneeded/broken. Once you find something you think will work, get permission from your parents and approval from your teacher BEFORE you begin taking it apart.

Slideshow of Example Display Boards and YouTube of Examples

Teacher Created Example - Meat Grinder

In order to help students understand the expectations of this assignment, I have chosen a product that I will reverse engineering in a similar way to what students will do for this project. Each product will provide a unique challenge. Some steps will be easier then others. Students will find more information/interest in some aspects of the produce and other types of analysis will be less complicated/important. The analysis of a mechanical product may look very different from that of an electrical product. Don't try to follow my example too closely. Allow the reverse engineering of your product find its own course, and adjust your display/presentation to its unique qualities.

Product Identification

Examining the meat grinder I found a logo with the words "Maid of Honor" on the side of the hopper. On the underside of the legs I found an inscription " 2908520 U.S. PAT. 181507 & 181891 DES. & 183030 DES.". Since I do not know where this item came from, these marking are important clues to figuring out who made and marketed this product.

With only minutes of online research I was able to find out the Maid of Honor was a whole line of kitchen products sold by Sears. I found several images of my product.

This image is very useful because it show the original packaging and what looks like an instructions manual.

It was designed to be the "lightest of food grinders". It was consider "portable".

It was sold as a 'meat grinder" and "food chopper"

It advertised its "removable Malagasy hopper".

From an Ebay post is looks like this product was sold in the 1960's.

From a Go Antiques page selling one for $29.98 it looks like it was available in the 1950's.

Visual Analysis - Example Visual Analysis: Meat Grinder

Functional Analysis - Example Functional Analysis: Meat Grinder

Meat Grinder - Functional Analysis

Structural Analysis - Example Product Disassembly Chart: Meat Grinder

Making a CAD Model of the product