1	Reverse Engineering Created by Jim Piper and Rachel Murdell with assistance from Dr. Gary Kinzel, Dr. Blaine Lilly, Dr. Tony Luscher The Ohio State University
2	Reverse Engineering: Definition ��examining competitive or similar or prior products in great detail by dissecting them or literally taking them apart.� - Dym & Little �What does this do?� �How does it do that?� �Why would you want to do that?�
3	Reverse Engineering: Rationale Allows us to gain insight into our own design problem by looking at how other designers have addressed similar issues. Restrictions: Expensive designs Protected by patents May be the competitor�s design Design may not work very well
4	Reverse Engineering: Methodology
5	Reverse Engineering: Methodology 1. Investigation, Prediction and Hypothesis Develop black box model Use / Experience product List assumed working principles Perform economic feasibility of redesign State process description or activity diagram
6	Reverse Engineering: Methodology 2. Concrete Experience: Function and Form Plan and execute product disassembly Group defined systems and components together Experiment with product components Develop force flow diagrams Identify function sharing and compatibility Transform to engineering specs. and metrics
7	Reverse Engineering: Methodology 3. Design Models Identify actual physical principles Create engineering models and metric ranges Alternatively or concurrently build prototype to test parameters
8	Reverse Engineering: Methodology 4. Design Analysis Calibrate model Create engineering analysis, simulation or optimization Create experiment and testing procedures
9	Reverse Engineering: Methodology 5. Parametric Redesign Optimize design parameters Perform sensitivity analysis and tolerance design Build and test prototype
10	Reverse Engineering: Methodology 6. Adaptive Redesign Recommend new subsystems Search for inventive solutions Analyze force flows and component combinations Build and test prototype
11	Reverse Engineering: Methodology 7. Original Redesign Develop new functional structure Choose alternatives Verify design concepts Build and test prototype
12	Reverse Engineering Example: �Black and Decker Hedge Trimmer
13	Reverse Engineering Methodology Flowchart
14	Reverse Engineering - Example Project 1. Investigation, Prediction and Hypothesis Develop Black Box Model Assemble product and conduct a test What goes in? What comes out? (i.e. power, noise, heat, vibration)
15	Reverse Engineering - Example Project
16	Reverse Engineering - Example Project What is the market for this product? �Suitable for small shrubbery� � Black & Decker Product Catalog Homeowners with small yards and limited budget For use only 3-4 times a year What are the costs associated with this product? Design - Manufacturing - Assembly � Packaging - Resale ($40.00)
17	Reverse Engineering - Example Project How long will this product last? Assumed durability of each component� (outdoor use, dirt) Availability of replacement parts and service shops What features does this product have that are important? Molded-in cord retainer Lock off switch prevents accidental start-up Lock on switch for continuous running Lightweight design for less fatigue (4.5 lbs.)
18	Additional Comments and Remarks -1
19	Additional Comments and Remarks -2
20	Additional Comments and Remarks -3
21	Patent Search on Hedge Trimmers
22	�
23	Reverse Engineering - Example Project Hedge Trimmer Sub-Systems and Interactions
24	Reverse Engineering - Example Project Motor 120 V - 8 Amp Motor 350 RPM Why not batteries? How important is size, speed? Was weight a consideration?
25	Reverse Engineering - Example Project Switch Safety lock allows trigger action. Is this a regulatory requirement? Ergonomic issues of size and lever force What type of spring mechanism is used?
26	�
27	Reverse Engineering - Example Project Blades How fast do the blades need to move? Force? Are the blades sharp? What are the blades made of ? How do the blades cut?
28	Reverse Engineering - Example Project Case How was the case made? Was the case designed to be esthetically pleasing? Why isn�t the case made out of metal? What sort of costs are involved in the manufacturing of this case?
29	�
30	�
31	Reverse Engineering - Example Project 3. Design Models Identify actual physical principles Create engineering models and metric ranges In this case, let�s take a look at the method of driving the blades. The motor turns a gear, which then connects to the upper blade at a pin joint driving the blade back and forth.
32	Reverse Engineering - Example Project 3. Design Models In order to determine how fast the blades are moving we can develop a kinematic relationship between the rotational speed of the gear and the horizontal velocity of the blade:
33	Reverse Engineering - Example Project 4. Design Analysis Calibrate model Create engineering analysis, simulation or optimization Create experiment and testing procedures
34	Reverse Engineering - Example Project 5. Parametric Redesign Optimize design parameters Perform sensitivity analysis and tolerance design Build and test prototype
35	Reverse Engineering - Example Project 6. Adaptive Redesign Recommend new subsystems Search for inventive solutions Analyze force flows and component combinations Build and test prototype
36	Environmental Impact To determine the environmental impact of the existing design evaluate each step of the Product Life Cycle Pre-production Manufacturing Process Product Life The After Life
37	Pre-production Replaceability of natural resources Availability of an alternative resource Energy required to obtain material Energy to process material Amount of waste created during processing Waste disposal method
38	Manufacturing Process Energy to produce component Waste created during production Type of waste- solvents, emissions? Reuse of in-process material waste? Raw material yield ratio
39	Product Life Energy consumption Waste production Length of product life Example:� Automobile
40	Product After Life Reuse Recycle- design for disassembly? Neither- harmful pollutants?
41	The End
42	Force Flow Diagrams
43	Force Flow Diagrams Treat forces like a fluid that flows in and out of the interfaces and through the component The fluid takes the path of least resistance through the component Label flow lines depending on type of stress that is occurring: Tension Compression Shear Bending
44	Force Flow Example 1 � Tee Joint Force flow through entire assembly (a) Force flow through nut (b) Force flow through bolt (c)
45	Force Flow Example 2 � Joint Force flow enters at left end and leaves at compression interface between tang and the pin. T � tension S � shear C - compression
46	Free Body Diagrams
47	Free Body Diagrams Definition: A simplified representation of an object (the body) in a problem that includes force vectors acting on the object. This body is free because the diagram will show it without its surroundings. This eliminates unnecessary information which might be given in a problem.
48	Free Body Diagram Example Consider a sailboat in the water being pulled by a rope (Use your imagination) We can simplify the boat in the water into a pictorial representation by creating our �body� as a simplified figure resting on a floor.
49	Free Body Diagram Example Gravity First, we will investigate the force due to gravity. If acceleration due to gravity is g=9.8 m/s², the force by Newton�s Second Law is F = m g This force vector points downward as this is the direction in which gravitational forces act.
50	Free Body Diagram Example Normal The normal force prevents objects from falling in to whatever it is sitting upon. It is always perpendicular to the surface with which an object is in contact. In the case of the sailboat, we will ignore the effects of buoyancy and assume that the boat experiences a normal force by the floor. This force is represented with the script �N�.
51	Free Body Diagram Example Friction The frictional force is related to the normal force because both are due to surface contact with the body. The frictional force is parallel and opposes motion. Static friction occurs when a body is not moving. Kinetic friction occurs when a body is in motion. Friction is approximated as being proportional to the normal force. The constant is called the coefficient of friction. To summarize: Fs = m_s N Fk = m_k N
52	Free Body Diagram Example Push and Pull Another force that can affect an object is a physical push or pull. This could be someone pushing a cart or pulling a rope and does not necessarily have to be parallel or perpendicular to the object. In this case, the wind is pushing the boat. The wind force will be labeled with F_wind.
53	Free Body Diagram Example Tension Tension in an object results if a pulling force acts on it, such as a rope being used to lift a weight. Tension is usually considered constant throughout the rope and at both ends. The letter T will be used to represent tension in the free body diagram. This completes the free body diagram for the boat.
54	Patents Understanding the Patent Search Process
55	What is a Patent? A Patent is a Grant For invention By the government To the inventor In exchange for full disclosure of the invention
56	What Can be Patented? Composition, Construction, or Manufacture Of a substance Of an article Of an apparatus An industrial type of process
57	What Cannot be Patented? Any artistic creation Mathematical methods Business schemes
58	Importance of Patent Information Complete details of how an invention works The earliest, sometimes the only, publication of an invention Follows a strict standard and is easily accessible Wealth of information (> 6 million patents)
59	Who Benefits From Patents? Inventor Secure from competition for at least 17 years Can exploit invention for own gain The Public Invention becomes public knowledge Freely available technology after patent expires Cheaper and better products become available
60	Patents as a Technical Tool Patent Information Contains A technical solution to a given problem Detailed workings of the invention Defects in any prior designs Patent Information Helps Stop the reinvention of the wheel Save time, money, brainpower
61	Locating Patent Information Library CD Rom based � Patentview (1974 � present) Internet U.S. Trademark and Patent Office http://www.uspto.gov IBM�s Intellectual Property Network http://womplex.patents.ibm.com