ITEC 103-1

assembly drawings

- shows how each part of a design is put together - can be pictorial drawing or orthographic drawings - can be exploded or not

cutting plane line

- thick, dark line composed of a long dash, two short dashes and a long dash - optional cutting plane line can be used - short perpendicular lines with arrowheads pointing away from the line are added to each end to indicate the viewing direction or line of sight -arrows should point away from the view sectioned

detail drawings

-each nonstandard part will receive a detail drawing showing how the part looks when completed - it completely describes the part giving everything one needs to make it, including shape, size, material, finish - the part number followed by the part name is given below each detail drawing - detail drawings are not needed for standard parts such as screws, threaded fasteners, bushing, bearings

Lettering(Drawing)

.13" or 1/8"

Lettering(Title)

.25" or 1/4"

Characteristics of good sketching

1. Neat 2. Dark 3. Proportionate 4. Complete Data Labeling

Steps for Successful Freehand Sketching

1. Pencil-in lightly main overall shape 2. Pencil-in lightly main detail locations 3. Refine/darken details 4. Darken all important lines (clean the sketch) 5. Add dimension lines, supporting text, symbols, etc.

Dodecagon

12 sided, 15 degrees

oblique

2D rolled out to 3D. 45 degrees (one direction) circles and arcs are truly circular in the frontal view

EQ Triangle

3 sided, 120 degrees

Partial auxiliary

3 view with 4th view coming off the incline in the front view (90 degrees from surface)

isometric

3D 30 degrees (both direction) ellipses are used

Square

4 sided, 90 degrees

Pentagon

5 sided, 72 degrees

Hexagon

6 sided, 60 degrees

Octagon

8 sided, 45 degrees

Regular Polygon

A figure with 3 or more equal sides and equal angles on the corners

modify

A generic term used for changing your objects

panels

A grouping of commands/tools on the ribbon

Visable line

A heavy line that shows the form of an object. Also called an object line. (a wide solid line)

block

A pre-drawn image you can insert in your drawing to save time and make your file size smaller.

tabs

A series of Tabs make up the Ribbon (Home, Insert, Manage, etc) and organize the Tools into common groups.

limits

A setting to impose an 'artificial' boundary on your drawing that sets the area of the grid, and when turned on, limits you to drawing in the grid area.

Alphabet of lines

A system if lines of various thickness, appearance, and darkness, each having a specific meaning on technical sketches and drawings

Border line

A very heavy line that frames the drawing (a wide solid line)

Cutting Plane line

A very heavy line that shows where a line cuts through an object to show how the inside looks (a very heavy broken line, long dash 1", short dash 1/4", spaces 1/8")

Absolute coordinates

A way of inputting points based on AutoCAD's origin.

relative coordinates

A way of inputting points based on a starting point.

polar coordinates

A way of inputting points based on distance and angle.

layer

All objects are drawn on a layer. You can group objects (such as electrical) on a single layer and organize your drawing.

linetype

All objects are drawn with a particular linetype. Examples would be solid, center, dashed, etc.

plot

Also known as print. To make a hard copy of your drawing.

Tangents

An absolute correct point of intersection between line and circle, circle and arc, etc.

object

Any item that is in the AutoCAD database. Also known as an entity.

property

Any specific characteristic of an object such as layer, scale, linetype, start point, etc.

explode

Breaks a compound object into its component objects. Explodes a compound object when you want to modify its components separately. Objects that can be exploded include blocks, polylines, and regions, among others.

fillet command

Connects two lines, arcs or circles by means of a smoothly fitted arc of specified radius.

offset

Constructs an entity parallel to the specified one, either through a given point or at a given distance.

mirror

Create objects that represent half of a drawing, select them, and mirror them across a specified line to create the other half. The two specified points become the endpoints of a line about which the selected objects are mirrored.

dimension style manager

Creates new styles, sets the current style, modifies styles, sets overrides on the current style, and compares styles.

linetype scale

Determines how the linetype is displayed and plotted. To change it, type in LTSCALE (LTS) and try different values to get the look you want.

extend

Extends an object until it meets another object.

styles

Formatting that defines the look of text, dimensions, etc.

lineweight

How wide lines on an object are displayed on the screen and when printed.

where sketching is usually done

In remote places, thus it usually involves very little tools or instruments

Drafting

Language of industry

divide

Lets you divide an entity into several equal-length parts, placing markers along the object at the dividing points.

measure

Measures an entity and places markers at specified intervals.

erase

Permanently removes specified objects.

Sketching

Rough draft for drawings

Irregular Polygons

Some side lengths or angles different from the other

units

The basic drawing unit set for your drawing. For example, you can use inches or millimeters depending on your needs. You can also set the precision you want displayed, such nearest 1/4", 1/2" 1/64", etc.

selection set

The current group of objects selected for modifying.

entexts

The outer boundaries of the objects you have drawn.

Inscribed Polygon

The polygon fits inside of a base circle- the pats of the polygon touch the base circle

Circumscribed Polygon

The polygon fits on the outside of a base circle--the side are tangent or touch the base circle

drafting

The use of sketches, instrument drawings, CAD, to produce technical diagrams, supported by text.

tools

These are the icons that start the commands you use to draw, modify, etc.

drawings spaces

These is where you draw your designs.

status bar

This allows to see and change different modes of drawing such as Ortho, Osnaps, Grid, Otrack, etc. You can right click this area to toggle between icons and text for this area.

APPLICATION BUTTON

This button displays commands for printing, saving, drawing utilities and other non-drawing tools.

ortho mode

This is a drawing mode that allows you to draw only perpendicular lines. It is toggled on and off by pressing the F8 key.

snap

This is a drawing mode that allows you to snap your cursor to precise points laid out in a grid pattern. Toggle with the F9 key.

object snap

This is a method of 'snapping' to certain, precise points on an object. (Osnap)

quick access toolbar

This is for quick access to common commands like New, Open, Save, Plot

grid

This is pattern of dots displayed on the screen to guide you. It can be toggled on and off by pressing the F7 key

crosshairs

This is your cursor when it is in the drawing space.

chamfer command

Trims two intersecting lines a specified distance from the intersection and connects the trimmed ends with a new line segment.

trim

Used to trim objects such that they end exactly at cutting edges defined by other intersecting objects.

command line

When you type a command, you will see it here. AutoCAD uses this space to 'prompt' you for information.

cursor

Your cursor will change depending on what function it is performing in the program.

Short break line

a heavy wavy line it cuts off a narrow long object. (A wide line)

view

a particular area of your drawing

Hidden line

a thin line that has broken dashes. It shows a hidden edge also called an "invisible line". (dashes are 1/8" long with 1/32" space)

Section line

a thin line that shows a solid surface when a cutting plane line passes through it. Also called cross-hatching lines. (thin line normally drawn at a 45 degree angle)

Extension line

a thin line used to extend the size of the object being drawn so the dimension can be placed near the view. (a thin line that projects from an object)

Leader

a thin line with an arrowhead on one end. On the other end is a dimension or not. should not be 0 or 90 degrees. (A thin line used to show the parts related to the note or dimension)

Dimension line

a thin line with arrowheads on each end that touch the extension line. It is opened for the dimension. (A thin line the length of each dimension)

Center line

a thin line with long and short dashes. It shows the center of objects. (dashes are 1" long and the short dash is 1/8" with !/8" spaces)

Long break line

a thin line with several freehand zig-zags. It cuts off a wide object. (A thin line with zig-zags every inch or two)

major components of working drawings

a. assembly drawing b. detail drawing c. bill of material d. title block

section lining or cross hatching

added to the section view to distinguish the solid portions from the hollow areas of an object and can also be used to indicate the type of material that was used to make the object

section lining

always bound by visible lines

Ellipses

an oval shape

most descriptive view

apply dims to the

spokes and ribs

are not sectioned

hidden lines

are omitted from section views

zone

between the views

extension lines

can cross each other

Eccentric

circles that do not share the same center although the centers of each circle are all contained in a least one of the circles

Concentic

circles with common center

Sketching

clarify thoughts in a technical discussion, and record ideas quickly.

Most drawings

consist of Geometric Shapes (it is important for the drafter to be able to identify and construct geometric entities)

parts list

consists of an itemized list of all the parts to assemble one complete unit

section lining

different marterials have different patterns of lines and spacing

visible lines

do not overdraw section lines beyond..

blind holes

does not go all of the way through

working drawings

drawing from which a design is built; legal contacts that document the design details and specifications

Chamfer

edge/end that is cut off at some angle

overall dimensions

for the height, width and depth. should be the farthermost out

ribbon

has most of the commands/tools that you will use while you are working. It runs across the top of the drawing space and contains panels - each panel has a group of associated tools. Switch to different panels by clicking on the tabs at the top of the ribbon.

2 point

human like diagram depth lines diminish to 2 vanishing points

1 point

human like diagram oblique with non-parallel depth lines depth lines are projected from the frontal plane and diminish at the distant vanishing point rear lines parallel to frontal

30 degrees

if section lines are drawn appropiately at a 45 degreee angle are or appear nealy parallel or perpendicular to a prominent visible outline, change the angle to

small dimensions

inside of the overall dimensions

uniformly space

lines in section linings

sectional views

located by creating a cutting plane line in a one view

location dimension

may be the length from the edge of an object to the center of a feature

size dimension

may be the overall width of a part or the diameter of a hole

fasteners

on assembly sections are not sectioned

avoid dimensioning

on sectioned areas and over section linings

basic tools of freehand sketching

paper, pencil, eraser, and grid paper (although sketches are rough drafts it be as neat and professional as possible)

Avoid

placing dims inside of the drawings

avoid

placing dims on hidden lines

working drawings

rely on orthographic projection and many other graphical techniques to communicate design information for production

section lining

remove ... in the areas where the dimensions appear

avoid

repeating dims

Good lettering

requires use of guidelines

Fillet

rounded edge

average section linings

should be approximately 3/32" apart

section lines

should be drawing at a 45 degree angle to the horizontal

dimension holes

should be marked with a "o" with a "/" through it. should be marked on the circular view, using an angular, radial leader

dimension arcs

should be marked with an "R" on their circular view, using an angular, radial leader

Lettering

should be neat,dark,professional looking and should be done in all capital single stroke gothic alphabet.

section lining

should be reversed or mirrored on adjoining parts when doing an assembly drawing

section lines

should be thinner than visible lines

section lines

should be uniformly thin, even in weigh and with good resolution

visible lines

should never pass through an area of section lining

dimension lines

should not cross any line

partial section view

similar to a broken-out but usually covers a larger area but less than a half section

1/16" to 1/8"

space section lines ... apart depending on the size of the drawing

working drawings

specialezed engineering drawings that provide information required to make the part or assembly of the final design

cylindrical objects

the dimensions should be put in the rectangular views

.38" .25"

the first row of dimensions should be how far from the object? succeeding ones?

Dimensions

the systems of size descriptors on mechanical drawings. should be done in a systematic method, typical for industry. clear, neat and not crowded

pick

to select an object by 'left-clicking' on it

notes

use ___ to dimension repetitive features

Sketches

used for manufacturing, constructing, modifying, repairing, illustrating items in industry

sectional views

used to clarify interior or hidden details on a multi-view drawing of an object

guide line

used to keep lettering uniform in height (very light)

construction lines

used to layout the object and all of its features (very light)

assembly section

used to show the arrangement and relationship of parts that makeup an obect

pictorial section

used to show the arrangement and relationship of parts that makeup an object in a three dimensional view with a quarter to half of the object removed

offset section

used to show the cutting plane stepped at one or more right angle bends, but will eventually cut through the whole object

broken-out section view

used to show the material thickness of a hollow object

Full section view

used to show the object as if one half of the object was removed

half section view

used to show the object as if one quarter of the object was removed

aligned section view

used to show the shape of features that do not align with the vertical and horizontal center lines of the object

revolved section view

used to show the uniform shape of the object from end to end

removed section view

used to show the variable shape of the object from end to end

sectional views

usually replaces one of the principle view (top, front and side) but may also be an additional view or series of supplemental views depending on the type

general purpose section lining

usually represents cast iron. uses medium, thick, lines drawn at a 45 degree angle and spaced 1/8" apart

opposing directions

when 2 or more parts in a section are adjacent, use section linings in

thru holes

where it is not clear that a hole goes through an object

section lines

within a sectioned area must be parallel

outline sectioning

you may limit drawing section lines to areas adjacent to outline of sectioned areas, called ..., providing the drawing remains clear