Chapter 6 Assembly Drawings Topics Exercises Copyright 2010

Assembly : Topics Summary 6. 1) Definitions 6. 2) Views Used in Assembly Drawings

Assembly: Exercises Exercise 6 -1: Section lines in assemblies Exercise 6 -2: Working drawing

Assembly Drawings Summary Copyright © 2010 by K. Plantenberg Restricted use only

Summary Ø What will we learn in Chapter 6? → How to create an assembly drawing. → How to create a standard parts sheet. Ø Key Points. → Assembly drawings show individual parts fit together to make a machine. → A standard parts sheet contains purchased items. Copyright © 2010 by K. Plantenberg Restricted use only

Assembly Drawings 6. 1) Definitions Copyright © 2010 by K. Plantenberg Restricted use only

Assembly Drawing Ø What is an assembly drawing and why do we need them? An assembly drawing is a drawing of an entire machine or system with all of its components located and identified. We need to know how to put the machine together. Copyright © 2010 by K. Plantenberg Restricted use only

Parts List (Bill of Materials) Part#’s

Subassembly Drawing Ø Subassembly: Two or more parts that form a portion of an assembly. Ø Can you think of some examples of subassemblies? → A car engine → A bike derailleur → A compressor in an AC Copyright © 2010 by K. Plantenberg Restricted use only

Definitions Ø Does an assembly drawing normally show size? No. Its job is to locate parts. Ø How do we show the size of an individual part? A detail drawing is a drawing of an individual part, which includes an orthographic projection and dimensions. Copyright © 2010 by K. Plantenberg Restricted use only

Working Drawing Package Ø Working Drawing Package: A packet of drawings that gives the specifications necessary to manufacture a design. Ø A typical working drawing package A standard part sheet includes; contains information about → an assembly drawing, purchased items and will be discussed later. → detailed drawings, → and a standard parts sheet. Copyright © 2010 by K. Plantenberg Restricted use only

Drawing Order Ø Drawings included in a working drawing package should be presented in the following order. → → → Assembly drawing (first sheet) Part Number 1 Part Number 2. . Standard parts sheet (last sheet) Copyright © 2010 by K. Plantenberg Restricted use only

Assembly Drawings 6. 2) Views Used in Assembly Drawings Copyright © 2010 by K.

Selecting Views Ø Does an assembly drawing need a FRONT, TOP and RIGHT SIDE view? Sometimes Ø We need as many views as it takes to identify and locate each part. →It may only take one view. Copyright © 2010 by K. Plantenberg Restricted use only

Needed 3 views to locate all of the parts.

Needed only 1 view to locate all of the parts.

Sectional Views Ø Sectional views are used quite often when drawing assemblies. Ø Why? Assemblies often have parts fitting into or overlapping other parts and we need to look inside the assembly to see clearly. Copyright © 2010 by K. Plantenberg Restricted use only

Section Lines in Assemblies Ø Section Lines: Section lines in adjacent parts are drawn in opposing directions. → In the largest area, section lines are drawn at 45 → Next largest = 135 (- 45 o) → Additional areas = 30 and 60 → Smaller areas = The distance between the section lines may also be varied to further distinguish between parts. Copyright © 2010 by K. Plantenberg Restricted use only

Exercise 6 -1 Section lines in assemblies Copyright © 2010 by K. Plantenberg Restricted

Exercise 6 -1 Ø Draw the section lines for the assembly shown. Copyright ©

Fill in the section line is the largest area.

Fill in the section line is the 2 nd largest area. 45 o

Fill in the section line is the next largest area. -45 o

Fill in the section line is the last area. -30 o, smaller spacing

30 o

Assembly Drawings 6. 3) Things to Include/ Not Include Copyright © 2010 by K.

Things to Include / Not Include Ø When deciding what to include in an assembly drawing remember; → The purpose of an assembly drawing is to show the individual parts fit together. → It is not used as a manufacturing print. Copyright © 2010 by K. Plantenberg Restricted use only

Things to Include / Not Include Ø The assembly drawing should not look overly cluttered. → Some lines that are necessary in a detailed drawing may be left off the assembly drawing to enhance clearness. Copyright © 2010 by K. Plantenberg Restricted use only

Hidden Lines Ø Do we include hidden lines? Usually → They should be used wherever necessary for clearness. → They should be left off when they impair clearness. → When a section view is used, hidden lines should not be used in that view. Copyright © 2010 by K. Plantenberg Restricted use only

Dimensions Ø Do we include dimensions? Usually not → As a rule, dimensions are not given on assembly drawings. → If dimensions are given, they are limited to some function of the object as a whole. Copyright © 2010 by K. Plantenberg Restricted use only

Identification Ø Ballooning: A part is located and identified, in an assembly drawing, by using a circle containing the part number and a leader line that points to the corresponding part. Copyright © 2010 by K. Plantenberg Restricted use only

Parts List / Bill of Material Ø The parts list is an itemized list

Parts List / Bill of Material Ø Parts lists contain the → part number,

Parts List / Bill of Material Ø Parts lists contain the → Other information can be included, such as, stock sizes of materials and weights of the parts. Copyright © 2010 by K. Plantenberg Restricted use only

Parts List / Bill of Material Ø Parts are listed in order of their part#. Ø Part#’s are usually assigned based on the size or importance of the part. Copyright © 2010 by K. Plantenberg Restricted use only

The parts list may be placed in the upper right corner of the drawing. - Part# 1 is at the top.

The parts list may be placed in the lower right corner of the drawing. - Part# 1 is at the bottom.

Assembly Drawings 6. 4) Standard Parts Copyright © 2010 by K. Plantenberg Restricted use

Standard Parts Ø Standard parts include any part that can be bought off the shelf. → They do not need to be drawn. → Purchasing information is given on the standard parts sheet attached to the back of the working drawing package. Copyright © 2010 by K. Plantenberg Restricted use only

Standard Parts Sheet Example Copyright © 2010 by K. Plantenberg Restricted use only

Standard Parts Ø What type of information should be included? Copyright © 2010 by

General Fastener Specifications Ø Thread specification (for threaded fasteners) Ø Head/Point style or Shape and Name of the fastener Ø Fastener length or size Ø Fastener series Ø Material Ø Special requirements (coatings, finishes, specifications to meet) Ø REQ’D (i. e. number required) Copyright © 2010 by K. Plantenberg Restricted use only