ME/MECA 238A - Mechanical/Mechatronic Design Project I Course notes prepared by G.A. Kallio, based on The Mechanical Design Process, by D.G. Ullman ME/MECA 238A

I. Introduction to the Engineering Design Process Reading: Ullman, Ch. 1-4 ME/MECA 238A

What is Engineering Design? Solving a problem that is not fully-defined in terms of its requirements has a multitude of satisfactory solutions requires creativity and engineering knowledge in generating and evaluating solutions (iterative process) usually results in a piece of working hardware ME/MECA 238A

Textbook Design vs. Real Design Textbook design: “What size SAE grade 5 bolt is required to fasten two pieces of 1045 sheet steel, each 4 mm thick and 6 cm wide, which are lapped and loaded with 100 N?” Real design: “ Design a joint to fasten two pieces of 1045 sheet steel, each 4 mm thick and 6 cm wide, which are lapped and loaded with 100 N.” ME/MECA 238A

Measuring Effective Design Cost - Quality - Time (cheaper) (better) (faster) The cost of designing is small but design has a large effect on manufacturing cost, overall product quality and time-to-market (Figures 1.2, 1.3) ME/MECA 238A

Measuring Effective Design, cont. Product cost is committed early in the design process and spent late in the process (Figure 1.4) Changes made early in design process are more cost-effective than those made later (Figure 1.6) ME/MECA 238A

This Course … Focuses on product design, where the product solves a problem, or fulfills a genuine need there is an identifiable customer there are specific customer requirements the product requires engineering design the product will be manufactured and tested as a prototype ME/MECA 238A

Life of a Product Product development Production and delivery Use End of life (Figure 1.8) ME/MECA 238A

Concurrent Design Concurrent, or simultaneous, design has replaced the outdated “over-the-wall” design method (Figure 1.7) Most important feature: simultaneous development of the product design and manufacturing process ME/MECA 238A

Concurrent Design, cont. Design for “X” (DFX) X = M (Manufacturability) X = Q (Quality) X = A (Assembly) X = E (Environment) X = R (Reliability) X = S (Safety and Serviceability) ME/MECA 238A

The Design Paradox As the design process progresses, you gain knowledge but you lose freedom to use what you know (Figure 1.11) Time and cost normally drive the design project, so there is rarely an opportunity to start over or to redo a design ME/MECA 238A

Types of Design Conceptual design Selection design Configuration design (packaging) Parametric design Original design Redesign ME/MECA 238A

Design Teams & Personalities Extrovert vs. Introvert Fact- vs. possibility-oriented Objective vs. subjective Decisive vs. flexible ME/MECA 238A

Design Team Goal Solving a problem through: Collaboration Compromise Consensus Communication Committment ME/MECA 238A

Documentation Each team member must maintain a notebook (logbook) to document entire project development Bring notebook to all team and advisory meetings Notebook must be bound – no looseleaf pages; each completed page dated with your initials ME/MECA 238A

Overview of the Design Process Establish a need Develop project plan Determine engineering specifications Develop concepts Develop product ME/MECA 238A

Develop Project Plan (Ch. 5) Form design teams Identify tasks & objectives Estimate personnel, time, and other resources needed for each task Develop a task sequence Estimate costs ME/MECA 238A

Determine Engineering Specifications (Ch. 6) Identify the customers Determine customer needs (marketing) Determine relative importance of needs Evaluate competition & current customer satisfaction Convert customer requirements to engineering specifications ME/MECA 238A

Develop Concepts (Ch. 7-8) Functional decomposition Generate concepts for each function Evaluate concepts Product safety & liability ME/MECA 238A

Develop Product (Ch. 9-12) Generate components DFX Based upon spatial, strength, power, thermal, temporal, acoustic, etc. constraints DFX Materials & fabrication selection Modeling & simulation Prepare drawings ME/MECA 238A