foundations of engineering design I Class 10 – Sep 20 Intro to Manufacturing

today’s plan turn in practice assignment start thinking manufacturing disassemble dental floss manufacturing processes assignments & announcements

first, a reminder that the products we use and design are influenced by our culture

The current state of dental care in developing countries…… current state of dental care in some developing nations is quite different from ours

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manufacturing

there are over 40,000 materials and over 1,000 ways to process them Source: Djassemi, M. “A Computer-Based Economic Analysis for Manufacturing Process Selection”, 2008

selecting the processes by which a particular artifact is manufactured is complicated!

You are a member of design team trying to develop and launch a new product. You need to evaluate how (and whether) you can make the product economically. or do you need to make changes before the product can be profitable to sell?

What are some things you’d need to know about potential manufacturing processes in order to decide? Spend a few minutes thinking about it, and write down your thoughts.

pair – share what are some things you’d need to know about the mfg processes?

what are some attributes of an artifact that might influence the mfg process that was used to make it?

key artifact attributes what is it made out of? how many do we want? what shape is it? what size (e.g., mass) is it? how important are dimensions? how smooth is the surface? what are the wall thicknesses?

shapes some processes can make only simple shapes, others, complex shapes. not easy to quantify/describe shape.

shapes wire drawing, extrusion, rolling casting, molding, powder methods stamping, folding, spinning, drawing From New approaches to Materials Education - by Mike Ashby & David Cebon, Cambridge, UK, 2008

how many? imagine your task is to sharpen pencils.

how many? how would your process change as you moved from sharpening 10 pencils to sharpening millions of pencils?

dimensions tolerance = how important it is that dimensions are met. no process can meet an exact dimension what do you think tighter tolerance does to cost?

dimensions what do you think tighter tolerance does to cost? think of some general cases in which tolerances might be more important

come get two or three artifacts from the table + pick one thing from your backpack

describe each of the artifacts in terms of their key attributes (that influenced how they were made)

for each artifact… what is it made out of? about how many do we want? what shape category is it? what size (e.g., mass) is it? how important are dimensions? how smooth is the surface? what are the wall thicknesses?

report out share the description of one of your team’s artifacts

product dissection

come get two dental floss packages for your team. put one aside for later.

dental floss dissection ID the parts of the dental floss take the floss containers apart document (mfg) attributes of each part create a functional decomp notice how parts fit together

report out what did you find? how do the pieces fit together? share one or two of the findings from your team

your manufacturing presentations

presentations we’ll learn about four manufacturing processes: extrusion, injection molding, thermoforming, and stamping

injection molding _ Image taken from Cambridge Engineering Selector (CES)

Injection Molded Parts

extrusion _ Image taken from Cambridge Engineering Selector (CES)

Extruded Parts

stamping _ Image taken from Cambridge Engineering Selector (CES)

Stamped Parts

thermoforming _ Image taken from Cambridge Engineering Selector (CES)

Thermoformed Parts

presentations you’ll each give a 15 minute presentation on one process to your teammates. your specific process will be assigned. process assignments are posted on blackboard under Assignments  Competency Assignments  Competency Assignment 5

assignments Practice Assignments PA 9: ID mfg-related attributes (due 9/25) PA 10: draw the dental floss (9/25) posted on blackboard under assignments  practice assignments Upcoming Competency Assignments CA 5: mfg process presentation (due 10/2) posted on blackboard under assignments  competency assignments