Begin with a Helix along the Z axis. Make a sketch on the end of the helix and Swept along the helix with the Orientation along the Z axis. Create a path from the end of the Helix to the sketch origin. Tube the path. The Pattern Geometry the Tube along a Helix pattern with the same settings as the original helix. Then Pattern Geometry the entire model in a circle around the Z axis at 180°.