How to turn a spiral coil (helix) into a hollow tube

[Rtfm00]

I have a spiral wrapped around a central stem. I need to hollow out the spiral into a tube with a 1.5mm wall thicjness.

When I select the spiral, and choose “Shell” it SEEMS to do so, except that the far enf of the tube is blocked off.

Any idea what I might be doing wrong?

[SCALEMODEL]

If you select both sides when you shell, you will create a hole.

If you only selected one side you can add more sides in the history panel.

Top and bottom

[Rtfm00]

So simple. Thank you.