1. Understanding the Drafting Tools
Just Enough AutoCAD
Chapter 2
Understanding the Drafting Tools
Understanding the AutoCAD Coordinate System
Setting Up a Drawing
Using a Digital T Square and Triangle
Getting a Visual Reference with the Grid Mode
Selecting Exact Locations on Objects

2. Just Enough AutoCAD
Chapter 2
AutoCAD’s Coordinate System

3. Just Enough AutoCAD
Chapter 2
Drawing a line at a 45 degree angle.

4. Just Enough AutoCAD Chapter 2
To draw a horizontal line 10 units long using polar coordinates, do the following:
Click the line tool in the Draw toolbar.
Click a point to start the line.

5. Just Enough AutoCAD
Chapter 2
AutoCAD’s default system for specifying angles.

6. Just Enough AutoCAD Chapter 2
To continue drawing using Cartesian coordinates, do the following:
to draw a vertical line 2 units long.
to add another line segment similar to the first.
Enter C to “close” the set of lines.

7. Just Enough AutoCAD
Chapter 2
Optionally discuss the Dynamic Input method of entering data.

8. Setting Up a Drawing Just Enough AutoCAD Chapter 1
The Drawing Units dialog box lets you select between Imperial (feet and inch) or metric measurement types.
Choose Format > Units to open the Drawing Units dialog box.

9. The Drawing Units dialog box options
Just Enough AutoCAD
Chapter 2
The Drawing Units dialog box options
Type
Description
Architectural
Feet, inches, and fractional inches, as in 12’ -6”.
Engineering
Feet and decimal feet as in 12.5’ or 12’-6.5”.
Decimal
Whole and decimal units that can be anything (metric distances, decimal inches, decimal feet, or decimal miles, for example).
Fractional
Whole and fractional units that can be anything (fractional metric distances, fractional inches, feet, or miles, for example).
Scientific
Scientific notation for distances. Units can be anything (meters, angstroms, miles, astronomic units, parsecs, or light years, for example).

10. Just Enough AutoCAD Chapter 2
Setting up your drawing area
Suppose you are starting a drawing of a house plan. You know that the lot size is 100’ by 50’. First set up your drawing units to be Architectural and then do the following:
Choose Rectangle from the drawing. In the Command window, you’ll see the prompt
Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]:
2. Enter 0,0. This tells AutoCAD you want the first corner of the rectangle at the origin of the drawing, which is the lower-left corner of a new drawing. If you remember your high school geometry, 0,0 is the coordinate for the origin of an XY graph. You’ll see the next prompt
Specify other corner point or [Dimensions]:
3. Enter 100’,50’ to draw a 100’ by 50’ rectangle. The value you entered, 100’,50’ is a coordinate that is 100’ in the X direction and 50’ in the Y direction.
4.The rectangle is larger than the display of a new drawing, so to view the entire rectangle, choose View  Zoom  Extents.

11. Just Enough AutoCAD
Chapter 2
To force AutoCAD to point in either a vertical or horizontal direction, use the Ortho
Mode in the status bar...
Or use Polar Tracking...
Polar Tracking will display a “tracking vector” as you draw.

12. Just Enough AutoCAD
Chapter 2
A grid of dots can be displayed by clicking the Grid button in the status bar.
You can also have the cursor snap to the grid points by clicking the Snap button in the status bar.

13. Just Enough AutoCAD
Chapter 2
You can change the snap and grid spacing using the Drafting Settings dialog box. To open this dialog box, right click on the Grid or Snap button in the status bar and choose Settings.

14. Just Enough AutoCAD
Chapter 2
Osnaps let you select exact locations on an object such as a line’s endpoint or midpoint.

15. Just Enough AutoCAD Chapter 2
You can set up osnaps using the Object Snap tab of the Drafting Settings dialog box. To open this tab, right click on the Osnap button in the status bar and select Settings.
With the Object Snap tab open, you can choose the location on an object, such as endpoints or midpoints.

16. Just Enough AutoCAD
Chapter 2
Turn on Osnaps by clicking the Osnap button in the status bar. With Osnaps on, AutoCAD automatically selects the object snap locations set in the Drafting Settings dialog box.

17. Just Enough AutoCAD
Chapter 2
Even with the Osnap button off, you can select Osnaps on the fly by pressing Shift+right-click while selecting points. A menu appears with the osnap options.