Design for Manufacture and Assembly Introduction Note: this is an adaptation of a presentation from Dr. Denis Cormier, intended for use as an Intro to DfMA for students enrolled in Multidisciplinary Senior Design John Kaemmerlen10/31/13

 Stages of Product Development Process  Concept Development  System Level Design  Detailed Design  Prototype Build  Prototype Evaluation and Refinement  Production Ramp-Up  “D” = Design ….. Overview – where does DFMA fit?

 Concurrent Engineering  “An approach used in product development in which functions of design engineering, manufacturing engineering and other functions are integrated to reduce the elapsed time required to bring a new product to the market.” Source: Wikipedia  Longer initial design phase, but design it right the first time around.  DFMA is one element of concurrent, or simultaneous, engineering. What Does This Have To Do With DFMA?

 As we design components and subassemblies, one mindset is “we are just making one, as long as we can machine the parts and assemble the device, no big deal”  A better mindset is “what if my client wants to use our design to make 1,000 of these devices, or a million? Are there aspects of the design I should manage differently than what I might typically do?” Relevance to MSD

 Design for Manufacture (DFM)  Design individual components so that they can be manufactured as easily and inexpensively as possible while maintaining the required functionality  Design for Assembly (DFA)  Design assemblies of parts so that they can be assembled as inexpensively as possible  Minimize assembly time  Minimize the number of assembly errors DFMA Objectives

 Standardization – use or re-use of standard components across products, or across subsystems, saves design time and reduces the chances of error (e.g. buying a catalog circuit board that has the required functionality, vs. designing, building, and testing a custom board that is a “perfect match” to the needs  Could be a “make item” (i.e. an item made in your factory)  Could be a “buy item” (i.e. an item you purchase from a supplier such as screws, washers, grease, etc)  Material choices – metal vs. plastic vs. ceramic vs. ….. Ease of design, cost to machine, and material cost should all be considered Examples of DfMA approaches

 Solidworks is capable of generating a great deal of highly useful DFM&A analysis data  Design of plastic molded part features  Measurement of feature sizes, volumes, surface areas, etc.  Assembly animations  Clearance and interference checking  These issues will be relevant on some MSD projects Solidworks

 Review of fundamental machining processes  Milling, drilling, turning, etc  Guidelines to ensure that a part can be machined  Minimize the number of machine setups  Ensure that standard cutting tools are sufficient  Ensure that cutting tools can reach the surfaces to be machined without collisions  Ensure that cutting tools can remove the material that needs to be removed  Check achievable tolerances and surface finishes Design for Machining

 Many kinds of assembly  Manual assembly  Automated assembly  Welding, Brazing, Soldering  Gluing  Examples of DfA principles  Minimize the number of parts in the assembly  Make parts easy to grasp, move, orient, insert  Design to enable automated insertion into a tool or machine, and automated ejection  Minimize use of parts that make the sequence of the process less efficient (e.g. parts on an SMT circuit board that cannot withstand a reflow oven environment) Design for Assembly

 Design for Manufacturability Handbook  James G. Bralla  McGraw-Hill Reference