Introduction to Engineering Drawings By: Chris Vandelaar University Machine Services TEB Rm. 50 Resources: Doug Phillips – Previous MME259A presentation Interpreting Engineering Drawings 3 rd edition by Jensen & Hines

Engineering Drawings: The language of manufacturing How we communicate our intentions as designers Convey all necessary information to get things made, manufactured, modified, assembled

Engineering Drawings: Can be quite simple

Hydraulic Piston - Simple Part?

Engineering Drawings: Can be complex

Engineering Drawings: Contain only pertinent information To ensure all engineering specifications and requirements are met

What is pertinent Form – shape of the part Geometry – acceptable deviation from form Dimensions – sizes of forms and shapes Tolerances – acceptable deviation from dimensions Surface finish and or treatment Other General information - notes

Pertinent information??? Form: Shown with pictures Orthographic projection Orthographic views This shows: Third Angle Projection

Projection Standard is communicated by Simple Projection Symbols

First Angle Projection: ISO/Europe Like rolling the part on a table Third Angle Projection: North America Like walking around the part

Projection Symbols: The very first thing a manufacturer looks for. EXTREMELY IMPORTANT!

Orthographic Views Sometimes can’t show everything Additional Views may be required

Additional Views Include: Section Views Cut-away Views Broken Views Revolved Section Views Not as common

Section view – shows part form along specified line(s) – “SECTION LINE” (dashed)

Cut-away View – shows part form behind front face

Break Views: Allow use of larger scale for larger parts – Smaller drawings

Break View – for long parts Notice Important Features of Break View: Instance numbers-Indicate number of spaces and holes Break line in overall length dimension – Indicates the presence of a break view Break Lines Shorten views to better fit the page

Revolved Section Views – Show profile forms Difficult to do using solidworks Not very common these days

Engineering Drawings: Contain only pertinent information Pictures Orthographic and alternate views Lines – Different lines mean different things

Line Types Object Lines – Show Part Geometry or Form – Visible – (Solid Lines) Illustrate external features and outlines As if looking at the part – Hidden – (Dashed Lines) Illustrate anything behind the front face of the view As if looking through the part – Phantom – Show non existent/alternate parts or features

Object and Hidden Lines

Phantom Lines:

Line Types Object Lines – Show Part Geometry or Form – Visible – (Solid Lines) – Hidden – (Dashed Lines) – Phantom – (Dotted or short /long dash lines) Reference Lines – Show references – Center Lines – Long/short dash (alternating) – Section Lines – indicate views (short dash)

Reference Lines:

Line Types: Review

Engineering Drawings: Pertinent information Pictures Orthographic views Lines – Different types Dimensions – Show feature sizes

Dimension Types: Standard - incremental Base Line – absolute Ordinate – absolute Incremental: point to point – one position to the next Absolute: reference one single point (DATUM)

Dimension Types: ANSI Standards shown Baseline Ordinate Absolute Standard Incremental Ordinate Absolute

Other Dimensioning: Simple holes (mm) More complex holes (SAE – Inches)

Other Dimensioning:

Engineering Drawings: Pertinent information Pictures Orthographic and alternate views Lines – Different types Dimensions – Show feature sizes Tolerances – Allowable deviation from size

Tolerance Types: Basic – standard tolerance from title block Bilateral – shows allowable deviation from nominal – above or below Limit – gives two dimensions – anything in between accepted Symmetric – gives one tolerance – above or below nominal Min/Max – anything over or under Fits – alone, with, or without tolerance – References standard Engineering fits

Standard Fits:

Engineering Drawings: Pertinent information Pictures Orthographic and alternate views Lines – Different types Dimensions – Show feature sizes Geometric Dimensioning and tolerancing – (GD&T)

Geometric Dimensioning and Tolerancing: GD&T The allowable deviation from nominal form

GD&T Uses: 1.Datum – point of reference – Face, Edge or Hole 2.Symbol – type of deviation 3.Tolerance – allowable variation – Given as distance

Example of Geometric tolerance:

Example of Geometric tolerance: Labelled

GD&T uses symbols to communicate geometric specifications

Which area of this block is out of tolerance?

GD&T is the only way to guarantee correct form Dimensions only guarantee size

Drawing views: Contain some or all of the following: 1.Dimensions 2.Tolerances 3.Geometric Tolerancing 4.Surface finish information 5.Allowable tool mark information

Drawings Contain: 1.Drawing Templates or Borders 2.Drawing Views 3.Title Block 4.Revision Block 5.Notes – special or standard

Title Blocks: Can vary in: – Size – Content – Location

TITLE BLOCKS : Contain any information that cannot be communicated through orthographic views and dimensions. Examples: (not limited) Part materials Part quantities Authors – supervisors – inspectors Inspection information/standard Finishing info – Painting, anodizing, heat treating Customer info Company Info

Special Notes: Can be located anywhere on the drawing – In title block or specific views. Some times drawing views have notes that simply say, “SEE NOTE #” referring to standard notes in the notes field. Examples: 1.See Note #? (in drawing pain) 2.Supplier info (notes field) 3.Clearance hole only (in drawing pain view attached to dimension) 4.Remove all sharp edges unless specified (Notes field) 5.Part to be painted as per manufacturers instruction and specification (notes field) 6.Surface treatments as per ASTM standard “ “ (notes field) 7.Any information at all required to achieve design intention. FOR NON-STANDARD INFORMATION

THE END Introduction to Engineering Drawings By: Chris Vandelaar University Machine Services TEB Rm. 50 Resources: Doug Phillips – Previous MME259A presentation Interpreting Engineering Drawings 3 rd edition by Jensen & Hines