Class12_1

Today’s topics: • More on AutoCAD, dimensioning• Reminders:

– Design demo in 2 weeks– Exam in 2.5 weeks

DP…questions?

Exam

• Old exams are posted on the class website. Format and scope will be the same.

CAD

Bottom line….

A CAD file is a NUMERICAL DATABASE describing your part. It is not a picture. Need to adopt this mindset when making a CAD drawing.

AutoCAD

• Setting up drawings• Limits• Zoom window, zoom previous• Zoom all

Drawing aids

• ORTHO to restrict only horz/vert lines• OBJECT SNAP enables the cursor to

“snap” to existing object features, such as end points

• Types of object features to snap to• Running OSNAP• Command line OSNAP

More AutoCAD functionality

• Construction line type• More Modify commands: Fillet, Offset• More Modify commands: Mirror, Array

More AutoCAD: Layers

• Layers• Tip: the availability of layers is a great

feature of CAD…learn to use layers effectively (use lots of them)

• Do not draw on the 0 layer or the defpoints layers. These have special properties and should be reserved for that use.

More AutoCAD functionality

• LTSCALE• Layer properties (setting, by layer, override)• Change properties• Lineweight

Adding text to your drawing

• Text is an object, so can be moved, rotated, copied, etc.

• Need to specify the height of the characters so that they are suitable for your drawing

• Can define several text “styles” to make drawing text easier, command line “style”

• A spell checker is available, separately• Edit using “modify, text”

Dimensioning

• Semi-automatic• Opening a dimensioning toolbar• Setting dimensioning variables:

“Format/dimension style”

You are the engineer!

• You need to know the proper dimensioning conventions.

Exercise 5

• Please draw and dimension the object on the bottom of the handout.

• Set drawing limits!• Set up layers!• Use construction lines!• Dimension correctly

Exercise 6

• Please draw and dimension the object on the next slide.

• Draw 3 views.• Set drawing limits!• Set up layers!• Use construction lines!• Dimension correctly

Your drawing assignment

Draw a three-view orthographic projection of your device. Dimension completely.

Your goal should be to provide enough information so that someone can build your device.

Due as part of the Final Report.