In and Out Spiral- a K'nex Ball Machine Element

I call this element the In and Out Spiral because the ball enters close to the back bone, and as it goes down, it moves out away from the backbone but then moves in toward the backbone as it exits. Below is the parts list:

Rods:

White: 16

Yellow: 2

Red: 7

Gray: 9

Connectors:

Dark Gray: 19

White: 17

Other:

Blue Spacer: 2

Step 1: Backbone

Step 2: Outside Edge

This part gives the spiral its shape.