Creating Spirals

The Spiral tool draws an Archimedes spiral. The number of turns, distance per turn, start radius and thickness can be specified, as well as the number of points used to define the curve. Use the alignment modes on the Tool bar to temporarily override the insertion point. These modes change the alignment of the insertion point along the X axis of the bounding box surrounding the spiral.

 

Spiral Alignment Mode	Description
Align Object Left	Moves the insertion point to the left edge of the spirals’s bounding box, along the original X axis
Align Object Center	Moves the insertion point to the center of the spiral’s bounding box, along the original X axis
Align Object Right	Moves the insertion point to the right edge of the spiral’s bounding box, along the original X axis
Align Object Origin	Leaves the insertion point at the actual or original position

For information on using the Offset Insertion and Wall Insertion modes, see Offset Symbol Insertion Mode and Wall Insertion Mode.

 

To draw a spiral:

1.	Click the Spiral tool from the Basic palette.

2.	Select the insertion type and alignment from the Tool bar.

3.	Click to define the center of the spiral.

If this is the first time a spiral is placed in this session, the Spiral Properties dialog box opens. These parameters apply to subsequently created spirals; they can be changed later by accessing them from the Object Info palette.

4.	Specify the spiral properties.

Parameter	Description
Distance per Turn	Enter the distance between the outer edges of each turn in the spiral
Number of Turns	Specify the number of turns which determine the total sweep angle of the spiral; one turn equals 360 degrees
Start Radius	Enter the distance from the center to the beginning of the spiral
Increment (deg)	Specify the number of points used to define the curve; the higher the increment, the fewer the number of points (for example, an increment of five degrees means 360/5=72 points per turn)
Thickness	Specify the thickness value of the area between the outer and inner edge of the turn

5.

Click OK.

A spiral with the specified parameters is placed on the drawing.

To create a 3D spiral, see Creating Helix-Spirals.