Guys,
When making springs a couple of us here will create them using a excel worksheet to close the ends. The problem with the 3 helix idea is that the changeover creates a sharp edge. This sharp edge also creates confusion on drawings.
The helix is created in excel to output a set of x,y,z points, which are then imported into SW. The spring is partially parametric, in that you can respecify the file you want to use the points from.
With the new design binder you can also save the excel sheet with the model.
A little helper for this:
6 points per rotation minimum to get a smooth curve.
Create a extra point very close to the ends of the curves to get near continuous curvature. (haven't yet tested 2005 on this to see if it fixes it)
File size can be larger using this method, but if the spring is important, then it helps.
Craig