I. Concepts You Need to Know and Basic Operations
Command Execution
CAD has many commands. You can execute them in two main ways. First, enter the command (or click the button) and then perform the operation. Second, select the object first and then run the command. Many commands support both ways.
Transparent Commands
Most commands run once and then stop. You can only finish or cancel them. But some commands allow another command to run during execution. For example, while command A is running, you can run command B. After command B finishes, command A continues. These are “transparent commands.”
Object Selection
You can select objects in two ways. If you drag from the upper left to the lower right, you select only objects completely inside the frame. If you drag from the lower right to the upper left, you select all objects that the frame touches, plus those inside.
Relative Coordinates
Relative coordinates use the current point as a reference. For example, to draw a 1000 mm line, choose the command, pick any point, and set the direction. If you want a vertical or horizontal line, press F8. Then type 1000 and press Enter or Space. You now have a 1000 mm line.
Keyboard Operations
You can type commands directly on the keyboard anytime.
You can use either the full name or the abbreviation.
Space and Enter work the same. Both execute the command.
To repeat the last command, just press Space.
Mouse Operations
Left click selects or confirms.
Right click confirms during a command, or ends continuous operations. It works like the Space key but offers shortcuts. If no command is running, right click shows a menu. By default, it repeats the last command.
Scroll wheel zooms in and out. Double-click the wheel to fit all drawings on the screen. Hold down the wheel to pan the screen.
If you flip the mouse over, the laser or wheel faces up. Then the mouse will stop working.
II. Shortcut Keys and Drawing Preparation
F8 – Orthogonal Mode
F8 turns orthogonal mode on or off. When it is on, you can only draw horizontal or vertical lines. When you move or copy objects, you can only move horizontally or vertically. This is very useful for straight lines. Get used to F8 early.
F3 – Object Snap
F3 turns autosnap on or off. When it is on, yellow symbols appear when you hover over objects. “口” marks an endpoint. “^” marks a midpoint. Learn these symbols well.
Snap Settings
At the bottom of the screen, find “Object Snap.” Right-click it and choose “Settings.” A list of symbols will appear. Select the ones you need or select all. Click “OK” to finish. Left-clicking the snap button works the same as pressing F3.
Shortcut Buttons
Sometimes another computer may not show shortcut buttons or the dimension menu. You can fix it yourself. Right-click in the gray area outside the drawing space. A long list of ACAD menus appears. Items with a √ show on screen. If “Dimension” is missing, click it to enable. Then drag it where you like.
CTRL+S – Save
Press CTRL+S often to save your work. Hold CTRL with your left pinky and press S with another finger. Always save after each step. Computers may crash, power may fail, or CAD may show a “fatal error.” If you don’t save, you may lose a lot of work. Saving should become a habit.
Customize Commands
You can create custom shortcuts. First, remember the basic commands. Then go to Tools > Customize > Edit Custom File > Program Parameters (acad.pgp). Commands with “;” are comments. The first line without “;” starts the command section. For example:
3A, *3DARRAY
Here, “3A” is the shortcut. “3DARRAY” is the full command. Typing “3A” runs the same command as typing “3DARRAY.” Save the file, close CAD, and reopen it. The new shortcut will work.
ESC – Cancel
Press ESC anytime to cancel the current command.