3D MINI: Extrude Curve Along Path

 Extrude_Curve4
Make an unusual closed curve shape with the EP Curve Tool with Curve Degree set to 1 Linear. (in the top view?)
Curve
To close curve: Select curve and then Curves > Open/Close *Note, if you select it twice, it will open again.
Curve-OpenClose
Adjust your curve.
Curve-Move
Activate the Move Tool to determine where the manipulator is located.  The location of the Manipulator is the point where the curve follows along the path.
Curve-pivot
Make sure it is centered or in a location suitable for extrusion.  A quick way would be to center the manipulator.   Modify > Center Pivot
Curve-pivot-center
To manually move the manipulator press {Insert} on the keyboard and then manually move it.
Curve-pivot-manual

Now make a fun curve to be used as a path for extrusion with the EP Curve Tool with Curve Dergree set to 3 Cubic.  Basically reset the tool.  (in the front view?)


Select the curved curve shape that you want to extrude and then {Shift} select the path.
Perspective_Window2
Open the Extrude menu option box Surfaces > Extrude ❑


Extrude_Curve_Settings  
SETTINGS:
  • Style: Tube
  • Result Position: Path
  • Orientation: Path Direction
  • Output Geometry: Polygons
  • Type: Quads
  • Tessellation Method: Count
  • Count: 200 – 500?

Now hit Extrude . . . and it should look something like this.
 Side2 

*If it doesn't look like this, you might have drawn your curve in a reverse direction, which makes the extrusion turn black.  Basically, a polygon has a front and a back and you want the sides receiving light on the outside.  If it is back on the outside either reverse the base curve direction, select the base curve and Curves > Reverse Curve Direction  OR select the output mesh and Mesh Display > Reverse. 
Side1
Extrude Settings:
Extrude_Curve5
Scale: This will adjust the scale of the closed curve along the path.
Rotation: Rotates the closed curve shape along the path
Change the Scale percentage under extrude setting to something like  0.1 to 0.01 .  Your extrusion should scale down to a point.
Side3
Press {3} to show the mesh with a smooth preview.
Side4
Assign a new material, that shows a specular highlight like Blin.
Side5
Perspective_Window3

Or this . . .
Extrude_Curve


Finally, repeat and make a second curve and intertwine with the first curve.
curved