You can control pitch values along the length of the profile and you can control the profile shape. Both of these options are valuable when you want to create a nontraditional spring.
You control the pitch along the profile by placing Sketcher points at the locations you want the pitch to be different. When you specify a variable pitch for the helical sweep, you must first specify the pitch at both the start and end of the trajectory. You can then select additional Sketcher points and specify the pitch at that location.
As you specify the pitch at the various Sketcher points, the system builds a pitch graph so that you can view the pitch specified at each point. In the left image of the lower figure, the pitch begins at a value of 1, increases to 4, and then decreases back to 1. This is in contrast to the left image of the upper figure, where the pitch is a constant value of 1 along the entire profile.
You can control the profile shape based on how you sketch it. The following are examples of the resulting spring shape for a given sketched section:
To use the Norm to Traj option, the profile entities must be tangent to each other.