AutoCAD is the world's best selling Computer Aided Drafting program. It is available in two versions, AutoCAD LT which draws only in 2D and AutoCAD which is 2D and 3D capable. For this project you will need AutoCAD.
A coil is known in AutoCAD as a Helix and as such there is a specific tool in the program to draw such objects. This command can be used to draw springs and screw threads as well as coils.
Open AutoCAD. Click on the Draw menu and select the Helix tool
Place the centre point of the base as prompted by the command line. Do this by either left clicking with your mouse or entering a coordinate.
Specify the radius of the coil's base, This can be done by left clicking with your mouse or typing a distance and hitting Enter.
Specify the Coil's radius at the top. If it is the same as the base radius you can just press Enter again. Otherwise left click or type the distance.
Input the height of the coil. This can only be done using a distance. Hit Enter, then go to the View menu, pick 3D views and choose an Isometric view. You will now see your coil
There are several other parameters to explore before inputting the height when creating your coil. These are accessed using the options shown at the command line; Turn allows you to define the number of turns in the height you define Turn Height sets the height of each turn and therefore the number of turns that will appear once you define the overall height Twist sets which way the coil turn; Clockwise or Counter Clockwise