Faculty Use and Sources For Standards

Examples & Standards

Uses in Capstones

Projects (Conceptual, virtual or real) using realistic design constraints. CAD systems are theoretical unless ‘real’ values are used Research into standards (examples of what particular standards control some part aspect, details in standards beyond handbooks, specific basis for municipal / state / national codes, etc.)

US Domestic StandardsMost by gift or discount from SDO, broker

Mechanical Engineering – Materials, fasteners, metrology, fits dimensioning & tolerances, tools, 3D CAD

Nuclear Engineering – Materials, design, plant construction, operational parameter

Electrical/Computer Engineering– Materials, components, circuit protocols,networking, communications

International StandardsMost free from ANSI or discount from SDO, broker IEC (International Electrotechnical Commission) – Devices, techniques for electrical and controls systems (many co-branded)

ISO (International Organization for Standardization) – Almost everything from banking to mining to fasteners to medical devices

ITU (International Telecommunications Union)– Telephony, television, networks (think 4G)

ABET — Criterion 5 - General Curriculum (2011-2012)

Students must be prepared for engineering practice through a curriculum culminating in a major design experience based on the knowledge and skills acquired in earlier course work and incorporating appropriate engineering standards and multiple realistic constraints.

Case Study: Simple Mechanism toIllustrate the Ubiquitous Nature of Standards

Even a simple device can require complex real-world decision-making based on the use of standards

Project Presented as a 3-Part Capstone via ECOs

Key Concepts: ECO, unit conversion using hard conversion, a practice common in metric countries. Add metric parts as teams both discrete and systems thinking

required.

Task: In three phases, design a Customary Inch arbor press in SI preferred numbers according to ECOs

How many standards?Hint: Over 22!6 fasteners, 4 threaded holes, 2 clearance holes, 3 fits, 1 finish,2 plating, 2 counterbores, knurling,preferred numbers, SI sheet metal,ring groove, gears, others.(ASTM, ASME, ISO)

Task: Redesign a Customary Inch arbor press in SI preferred numbers

ECOs: Convert inch dimensions and parts to SI preferred numbers. Retain approximate trade size, calculate mass properties, add GD&T.

ECO1 & 3 are individual phases, ECO2 is accomplished as teams.

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Unit Conversion

Choice Choice Choice Choice1st 2nd 3rd 1st 2nd 3rd 1st 2nd 3rd 1st 2nd 3rd1 5.2 23 65

1.1 5.5 24 661.2 5.8 25 68

1,3 6 26 701.4 6.2 28 72

1.5 6.5 30 741.6 6.8 32 75

1.7 7 34 761.8 7.5 35 78

1.9 8 36 802 8.5 38 82

2.1 9 40 852.2 9.5 42 90

2.4 10 44 922.5 11 45 95

2.6 12 46 982.8 13 48 1003 14 50

3.2 15 52 105 1023.5 16 54

3.8 17 55 1084 18 56 110

4.2 19 58 1124.5 20 60 115

4.8 21 62 1185 22 64 120

Renard Numbers (ISO 3)

Drill sizes to preferred numbers

Issues with fasteners

• CAD models vs. real sizes• Thread length vs. tap drill hole depth• Costs vs. functionality• Clearance holes• Other clearances

Issues with virtually all headed fasteners

Ref. ASME B18.3.3-1986, Hex Socket Head Shoulder Screws

Task: Redesign a Customary Inch arbor press in SI preferred numbers

ECO 2: As a team resolve issues when using assembly parts from each team member. Substitute standard parts for certain

non-standard parts, substitute

fasteners. build mating features using

standard metric fits. Retain approximate trade

size, add additional

intelligent properties.