Suggested Technique for Creating a Helical Spring Around a Non-Linear
This technique will go through the steps for creating a helical shaped solid
using a variable section sweep, a sketcher relation that makes use of the
trajpar parameter and a swept protrusion. This technique does not use the actual
#Helical Sweep feature.
- Sketch a curve that defines the trajectory (shape) of the spring. Then
create another curve parallel to the original by selecting #Feature, #Copy,
selecting on the original curve and using the #Translate option to create a
copy that is parallel to the original curve.
- Create a surface using a variable section sweep: Select #Feature, #Create,
#Advanced, #Done, #Var Sec Sweep, #Done. Select the default options for the
feature, select one curve for the Origin Trajectory and the other curve for
the X-Vector trajectory. Then sketch the section below. Note: Actual
dimensions may vary.
Before completing the section, write the following sketcher relation: sd#
= trajpar*360*N, where sd# is the symbol of the angular dimension in
the sketch and N is the number of coils.
- Next create a swept protrusion using the outside edge of the surface as
your trajectory: Select #Feature, #Create, #Protrusion, #Sweep, #Solid and #Done.
Use the default options for the feature and when selecting the trajectory,
use #Tangent Chain and select the outside edge of the surface. Now sketch
your desired section on the cross-hairs (centerlines) as seen below.
- Finally, the surface and datum curves may be placed on a layer and blanked
to show the resulting helical coil.