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

**URL:** <https://discourse.shapr3d.com/t/how-to-turn-a-spiral-coil-helix-into-a-hollow-tube/36519>\
**Category:** Modeling Questions\
**Created:** [February 14, 2025, 2:14am UTC](https://discourse.shapr3d.com/t/how-to-turn-a-spiral-coil-helix-into-a-hollow-tube/36519 "2025-02-14T02:14:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Rtfm00](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/rtfm00/32/21887_2.png) [@Rtfm00](https://discourse.shapr3d.com/u/Rtfm00)\
**Post date:** [February 14, 2025, 2:14am UTC](https://discourse.shapr3d.com/t/how-to-turn-a-spiral-coil-helix-into-a-hollow-tube/36519/1 "2025-02-14T02:14:32Z")

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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?

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**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 14, 2025, 5:16am UTC](https://discourse.shapr3d.com/t/how-to-turn-a-spiral-coil-helix-into-a-hollow-tube/36519/2 "2025-02-14T05:16:57Z")

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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.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/7/4/749ef0e93f7ea145169f73567e6d7ca60c364728.jpeg)

Top and bottom

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/a/9/a969e52b1e61755cce335202a5fcd7356275d8d2.jpeg)

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<div class="post-metadata">

**Author:** ![Rtfm00](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/rtfm00/32/21887_2.png) [@Rtfm00](https://discourse.shapr3d.com/u/Rtfm00)\
**Post date:** [February 14, 2025, 5:43am UTC](https://discourse.shapr3d.com/t/how-to-turn-a-spiral-coil-helix-into-a-hollow-tube/36519/3 "2025-02-14T05:43:42Z")

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So simple. Thank you.