Engineering Design Notes

Dimensioning Standards

  • Length should be in the middle of arrows.
  • Aligned dimensioning is used.
  • For rotating parts, the dimensioned text should also rotate.
  • The center point of a chain measure is called a DATUM.
  • Location Dimensions: Dimensions used to determine the proximity of a line.
  • A fillet is the inside radius between two intersecting planes

Engineering Design Process

  • Define Problem
  • Generate Concepts
  • Develop Solutions
  • Construct and Test Prototype
  • Evaluate Solution
  • Present Solution

Tolerances

  • An acceptable amount of dimensional variation that still allows an object to function correctly.
  • Limit: Provides upper and lower limit.
  • Bilateral: An equal allowable variation (Uses Plus/Minus Symbol).
  • Unilateral: Provides an allowable variation in one direction (Separate plus and minus signs).

Functional and Visual Analysis

Visual Analysis

  • Elements:
    • Line
    • Color
    • Value
    • Shape
    • Form
    • Space
    • Texture
  • Principles:
    • Balance
    • Emphasis
    • Contrast
    • Rhythm
    • Proportion
    • Unity
    • Economy

Functional Analysis

  • Purpose is identified.
  • Observations determine product function.
  • Inputs and outputs are listed.
  • Springs, Conductors, Energy.
  • Displacement = Stretched Length - Natural Length
    • Displacement=StretchedLength−NaturalLengthDisplacement = Stretched Length - Natural Length

Human Centered Design

  • Human-centered design is a creative problem-solving process that focuses on designing from the perspective of the people you are trying to reach.
  • The design must meet people’s needs, be useful, and be compatible with the capabilities of the user.
  • The three phases of the human-centered design process are:
    • Inspiration
    • Ideation
    • Implementation

Holes and Hole Notation

  • Through-Hole: cuts through entire thickness.
  • Clearance-Hole: large enough to allow screw head to pass through.
  • Blind- Hole: does not cut through entire thickness.
  • Countersink: Conical-Shaped Recess around surface (Tapered Screw).
  • Counterbore: Cylindrical recess around hole at surface (Bolt/Nut).
  • Tapped: Has internal threads.

Symbols

  • -Diameter Symbol ⊘\oslash
  • -Counter Bore or Spot Face Symbol ∪\cup
  • -Counter Sink Symbol ▽\triangledown
  • -Depth or Deep Symbol