Lesson Title:
Working Drawings
Week
Day
National Education Standards
Math:
1.) Analyze characteristics and properties of two- and threedimensional geometric shapes and develop mathematical arguments
about geometric relationships
Science:
Technology: Visualization and CAD
Introduction:
A working drawing is a drawing that supplies the information and instructions necessary to
manufacture or construct a mechanism, structure or component.
Working drawings can take either of two forms:
1.) Detail Drawings
Supply the information necessary to manufacture a part or component. Detail drawings can
include orthographic and auxiliary views and all the dimensions and constraints required to
accurately describe the object. Working drawings often include an isometric or pictorial
view that describes the object similar to the drawing below.
2.) Assembly Drawings
Assembly drawings provide the information necessary to assemble 2 or more components
or structural parts. (See examples below)
Working drawings are legal documents. Since they are often sent to other companies (subcontractors) the drawing formats should conform to corporate, national or international standards.
The American National Standards Institute (ANSI) or the Canadian Standard Association are used
by significant numbers of North American Industries.
Assembly Drawings
Objective:
Students who complete this lesson will:
1.) Create a detail drawing of one or more of the components used in the construction of their
trebuchet.
2.) Create and assembly drawing of one or more of the mechanisms (Throwing Arm
Assembly) or structural assemblies used in the construction of their trebuchet.
3.) Use a defined standard format to dimension and present the drawings per the examples
above.
Terms:
Shape Description
Size Description
Specifications
Scale
Isometric
Orthographic
Perspective
Sectional Views
Auxiliary Views
Title Block
Tolerances
National Standards (ANSI)
Materials:
CAD Software
Engineering Drawing Text
CAD WorkStation
Drafting Tools
Printer
Lesson Text:
SolidWorks Tutorial 2003 by David C. Planchard and Marie P. Planchard (Chapter 3)
Activities:
Create detail and assembly drawings of the trebuchet and trebuchet
components.
Worksheets:
SolidWorks Tutorial 2003 by David C. Planchard and Marie P. Planchard (Chapter 3)
Resources:
Use available engineering drawing textbooks that cover dimensioning and
the creation of working drawings, multi-view drawings and assembly
drawings.
Assessment:
Based on the successful completion of CAD assignments. Note: Be
certain to preserve all your worksheets, assignments etc in chronological
order in your notebook.
Working drawings should contain the following information:
Shape Description
This includes all the views necessary to accurately describe the object or assembly. Sectional
views, auxiliary views and enlarged detail views may be required to provide all the visual
information needed to manufacture or assemble the component or structure.
Size Description
All the dimensions and tolerances that completely describe the size and location of shape features
on the part must be provided. Call out all required dimensions once. Do not include duplicate or
unnecessary dimensions.
Specifications
Specifications are notes and information pertaining to materials, finishes, heat treatment, general
tolerances and required quantities.
In addition to the required drawing information described above. It is always best practice to
include:
Drawing number and revision, scale, date, drawing authors name, company name address and
contact information.