In this autocad tutorial you’ll learn how to draw slot.
1. Open a new drawing. Click New 
2. Make sure Ortho mode is ON, (it ON when it glow in blue)
click the icon to turn it ON or OFF. (or press F8 to toggle)
3. Make sure Object Tracking Snap also ON and make sure snap to Quadrant is active too.
4. Type z [Space bar], e [Space bar]. This will zoom extents your drawing area.
5. Click Circle,
specify center at 0,0. Type 0,0 [Enter].
6. Specify circle radius to 1, Type 1 [Enter].
7. Click Copy to copy this circle 3 unit apart.
select the circle as object to copy. Press [Enter].
Specify base point of the copy. In this case center of the first circle. Click at center.
Move your cursor to right side and type 3 [Enter].
8. Press [Esc] few times to end copy command.
9. From the ribbon tools, click LINE
snap first point of the line at top quadrant of the first circle
and second point of the line at top quadrant of the second circle.
Press [Esc] few times to end line command.
10. Repeat step 9 for the bottom line of the slot.
Press [Esc] few times to end line command.
11. Click Trim,
select both horizontal line for trimming edge. Press [Enter].
12. Select object to trim, click on both inner circle edge.
Press [Esc] few times to end trim command and your slot is done.
