Line Conventions Line Conventions Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Project Lead The Way, Inc. Copyright 2007

Line Conventions Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Lines of varying style and thickness are used in specific ways to develop and communicate graphic messages about an object’s geometry. The next few slides show some basic line conventions and their use. Project Lead The Way, Inc. Copyright 2007

Line Conventions Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Construction Line Construction Line: Very lightly drawn lines used as guides to help draw all other lines and shapes properly. Ask students after slide first appears: What do you notice about this sketch? (Making sure you lead them into looking at the different line conventions or types that appear in the sketch). Imagine if all the lines here had the same thickness, weight and consistency. What do you think this sketch would look like then? Project Lead The Way, Inc. Copyright 2007

Line Conventions Object Lines: Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Object Line Object Lines: Used to define the object; they are thickest and darkest lines on a sketch. Object Line Project Lead The Way, Inc. Copyright 2007

Line Conventions Hidden Line: Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Hidden Line Hidden Line: Lines used to show interior detail that is not visible from that side of the part. Hidden Line Project Lead The Way, Inc. Copyright 2007

Line Conventions Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Center Line Center Line: Lines that define the center of arcs or circles; they are half as thick as an object line. STOP PRESENTATION: Students have the line conventions needed for the activities in Lesson 1.2. Center Line Project Lead The Way, Inc. Copyright 2007

Line Conventions Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Short-Break Line Short-Break Line: A freehand drawn line that shows where a part is broken to reveal detail behind the part. STOP PRESENTATION: Students have the line conventions needed for the activities in Lesson 1.2. Project Lead The Way, Inc. Copyright 2007

Line Conventions Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Section Lines: Lines used to define where there is material after a part of the object is cut away. Section Line STOP PRESENTATION: Students have the line conventions needed for the activities in Lesson 1.2. Section Line Project Lead The Way, Inc. Copyright 2007

Line Conventions Dimension Lines: Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Dimension Lines: Lines that are used to show distance or measurement. Arrows are drawn on the ends to show where the dimension line starts and ends. The dimension is usually located in the middle of this line. Understanding Line types and when to use them will help your sketches look cleaner and more professional. Dimension Line Dimension Line Project Lead The Way, Inc. Copyright 2007

Line Conventions Extension Lines: Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Extension Lines: Lines used to show where a dimension starts and stops on an object. Used with dimension lines to properly dimension an object. The line is 1/16” away from the part as to not get confused with the object lines. Understanding Line types and when to use them will help your sketches look cleaner and more professional. Extension Line Project Lead The Way, Inc. Copyright 2007

Line Conventions Long-Break Lines: Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Long-Break Line Long-Break Lines: Used to shorten very long objects that do not change in detail. The line is usually represented as a jagged cut or break. Understanding Line types and when to use them will help your sketches look cleaner and more professional. Project Lead The Way, Inc. Copyright 2007

Line Conventions Leader Lines: Introduction to Engineering DesignTM Unit 1 – Lesson 1.2 – Intro to Technical Sketching Line Conventions Leader Line Leader Lines: Leader lines are used to show dimensions of arcs and circles. Leader Line Project Lead The Way, Inc. Copyright 2007

Precedence of Lines Complex object sketches may require different line types to overlap Line precedence must be used Rules that govern line precedence in sketches and technical drawings Object lines take precedence over hidden and center lines Hidden lines take precedence over center lines Cutting plane lines take precedence over all others

Precedence of Lines Examples Object lines has precedence over hidden lines Object line has precedence over center line