bruce mayer, pe licensed electrical & mechanical engineer [email protected]

[email protected] ENGR-11_Small_Volume_Design.pptx1

Bruce Mayer, PE Engineering-11: Engineering Design

Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engineering 11

Engineering Designfor Small-Volume

Electro-Mechanical Systems



To Build a Designed Object Say you were Asked to BUILD or

CONSTRUCT something using basic hand tools

You would need (at a minimum)• A list of Parts with P/N’s and Qtys• Parts FABRICATED specially for this Object• Parts PURCHASED from Catalogs for this

Object (a.k.a. “Standard Parts”)• Instructions on how ASSEMBLE the Object



Small-Volume Object DesignRaw-Material in

Basic-Shapes (chosen by the

Engineer)

Parts Fabricated

per Specialized

designs (your

BluePrints)

Parts Purchased from Technical

Catalogs (Selected by the Engineer)

Assembly Documentation

(Parts-List, BluePrints,

Instructions, etc.) Written by the

Engineer



When Designing Something… Think About CRITICAL Issues

• Will It WORK• Will it Meet the SCHEDULE &

BUDGET• Can it be BUILT from MY

Design Documentation?– Ask Yourself: “If I were Building this

object What Info would I need?”



Discussion Scope We Examine what it takes to

BUILD small quantities (dozens to hundreds per year)of Engineering-Designed ElectroMechanical Systems for Sale

This Discussion Does NOT Address the FUNCTIONAL PERFORMANCE of the design; only what it takes to actually BUILD IT, regardless of how Well it works



BUILDING SomeThing is HARD Designing on Paper is MUCH EASIER

than Designing Something that must be BUILT and Ultimately Sold

The Build-Process exposes• Incomplete Design Documents

– Wrong Parts Purchased Incorrect Order Number

– Part-Purchase Delayed Incorrect Supplier Phone Number

– $-Costs much higher than estimated



BUILDING SomeThing is HARD The Build-Process exposes

• Incomplete Design Documents– Not Sufficient Information to Construct

BluePrints Missing/Incorrect Dimensions or Notes; e.g., Inconsistent Material CallOut Missing/Confusing Lines Missing Surface Finish

Schematics or Assembly Drawing Missing/Incorrect ID-Information; e.g., Missing Balloon CallOut for O-Ring, Bolt,

Valve, etc. Missing Value for Resistor or Capacitor



BUILDING SomeThing is HARD The Build-Process exposes

• Design Errors– Mechanical Elements do NOT FIT– Electrical Elements SHORT or do not PowerUp– Can Not be Fabricated or Assembled as

Designed– Mechanical Structures are NonRigid

“Floppy” or “Doingy” or “Cheesy” of “Wobbly”– Electrical or Fluid Systems are UnderPowered

or Noisy or Unstable “Whimpy” or “Flakey” or “Glitchy”



To BUILD an Engineered Design CORRECT & COMPLETE information

on PURCHASED-Parts Given to the “Purchasing Department”• NAMES & PHONE-NUMBERS

of ALL Suppliers• Correct Part-Numbers for ALL

Purchased Parts• Correct Order-Quantities

and Estimated $-Costs



To BUILD an Engineered Design Dot “i’s” & Cross “t’s” on

All FABRICATION Drawings (the “BluePrints”)• A single Missing-Dimension or Superfluous

Line or Missing Feature-Callout Brings Production to a HALT

• OMISSIONS result in ReWork or Scrap; e.g.;– Forgetting a needed Removed-Feature (Hole or

Slot or Notch or Groove)– Superfluous Removed-Feature (‘extra” hole)

http://wapedia.mobi/en/File:DIN_69893_hsk_63a_drawing.png



Designed Part (Piece Part)



To BUILD an Engineered Design COMPLETE Bill of Materials (“BoM”,

also called the “Parts List”)• EVERY Nut, Bolt, Washer, Wire-Connector,

Plumbing-Fitting, etc.,Listed on the BoM Table

• Complete CallOuts ALL parts shown with “Balloons” containing part ID-number

Clearly UNDERSTOOD Assy Dwgs• Don’t Confuse

the Assemblers



Typical Assembly Drawing

On-Dwg BoMBalloon CallOut



Tools at the Engineer’s Disposal INGENUITY & CREATIVITY

• MOST Important Knowledge of SCIENCE

and MATHEMATICS Technical CATALOGS “BluePrint” Making Software Standard Fabrication Methods

• Machining, Welding, Injection-Molding, etc.



Summary: Design Docs Include Purchased Part Information

• What Mfr-PN, Who Supplies, How Much $ Fabricated Parts Drawings (BluePrints)

• 100% Accurate; generate NO Questions from Fabricators

BoM or Parts List• 100% Accurate as it is used to “Pull Parts

from Stock” to Make an “Assembly Kit” NonConfusing Assembly Drawings



Small Volume Design FlowChartSupplier

Contact InfoPurchased Part

Catalog No.

PurchasedParts

Physical Design to Scale (LayOut)

MaterialSelection

Fabrication Notes

Formal “BluePrints”(Use Std TitleBlock)

To FabricatorMachine Shop, etc.

Fabricatorcontact Info

FabricatedPiece-Parts

Assy Parts List(Bill of Materials)

Order & ReceivePurchased Parts

Assembly Drawing & Documentation

Physical Assembly and/or Construction



All Done for Today

EngineeringDesign

Pyramid



Bruce Mayer, PERegistered Electrical & Mechanical Engineer

[email protected]

Engineering 11

Appendix

bruce mayer, pe licensed electrical & mechanical engineer [email protected]

Documents

pe engineering

engineering designbuilding

yearof engineering

engineering designwhen

engineering designto

design documentation

n s j o h n s o n c

fluid systems