Lesson 4: Precision

Precision

Make sure everything you draw is accurate.

AutoCAD gives you several tools to help you draw with precision. Here are the main ones:

• Polar tracking – helps you draw at set angles like 0°, 90°, or 45°
• Locking angles – lets you lock in a specific angle while drawing
• Object snaps (Osnaps) – snap to exact points like the end, midpoint, or center of shapes
• Grid snaps – snap to a visible grid
• Coordinate entry – type exact coordinates (X, Y) for a point

Most of the time, you’ll use polar tracking, locked angles, and object snaps to stay accurate.

Polar Tracking

Polar tracking helps guide your mouse to specific angles when you’re drawing.

For example, if you want to draw a horizontal line:

1. Start the Line command
2. Click the first point
3. Move your mouse to the right
4. Type the distance (like 100) and press Enter

By default, polar tracking helps you draw perfectly horizontal or vertical lines (0° or 90°).

Locking Angles

If you want to draw a line at a specific angle, you can lock that angle.

For example, to draw at a 45° angle, do this:

1. Start the Line command
2. Type <45 (with the “less than” symbol)
3. Move the cursor in that direction
4. Type the length you want and press Enter

This is great for slanted lines or angled shapes.

Object Snaps (Osnaps)

Object snaps help you click exactly on key points of objects.

For example, if you’re drawing a new line and move your mouse near the end of another line, AutoCAD will “snap” to that endpoint.

There are different Osnap types:

• Endpoint
• Midpoint
• Center (for circles)
• And more

Setting Your Default Osnaps

You can choose which Osnaps are always on by typing OSNAP in the command line.

Many users turn on:

• Endpoint
• Midpoint
• Center

These help you draw faster and more accurately.

Useful Tips

• If you only want to use a specific Osnap once, hold Shift, right-click in the drawing area, and choose from the list.
• Zoom in close before snapping—this helps you avoid clicking the wrong point.
• Mistakes in snapping can cause errors in your whole drawing.

Object Snap Tracking

Object Snap Tracking lets you line things up vertically or horizontally based on other points.

Here’s how it works:

1. Hover your mouse over one point (like an endpoint)
2. Hover over another point
3. Move your mouse to a new spot—the cursor will lock in to line up with both previous points

Now you can click and finish your shape exactly where you want it.

Check Your Work (Distance Tool)

Want to double-check your drawing?

Use the DIST command (or type DI) to measure the distance between two points.

Example: You want to know how far a table is from a wall.

1. Type DI
2. Click the first point
3. Hold Shift, right-click, choose Perpendicular, and click the second point

The distance will appear, and the UNITS command controls how many decimals are shown.

Helpful Function Keys

AutoCAD’s F-keys on your keyboard toggle useful settings:

• F3 – Object Snap
• F8 – Ortho Mode (draw straight horizontal/vertical lines)
• F9 – Snap to grid
• F10 – Polar Tracking

Note: F8 and F10 cannot be used at the same time—turning one on turns the other off.