# Subtract spiral of ring

**URL:** <https://discourse.shapr3d.com/t/subtract-spiral-of-ring/13082>\
**Category:** Modeling Questions\
**Created:** [May 31, 2021, 12:22am UTC](https://discourse.shapr3d.com/t/subtract-spiral-of-ring/13082 "2021-05-31T00:22:10Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![lukasf](https://avatars.discourse-cdn.com/v4/letter/l/57b2e6/32.png) [@lukasf](https://discourse.shapr3d.com/u/lukasf)\
**Post date:** [May 31, 2021, 12:22am UTC](https://discourse.shapr3d.com/t/subtract-spiral-of-ring/13082/1 "2021-05-31T00:22:10Z")

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hey there,

I’m trying to subtract a spiral out of a ring but somehow the done button won’t appear. With a closed ring its possible. Has anybody an idea why?

 ![Screenshot 2021-05-31 at 02.15.50](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/b/b03e6d857f140ea22bafa9eeef11b2c077a6febb.jpeg)

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**Author:** ![TigerMike](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/tigermike/32/32650_2.png) [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)\
**Post date:** [May 31, 2021, 12:51am UTC](https://discourse.shapr3d.com/t/subtract-spiral-of-ring/13082/2 "2021-05-31T00:51:33Z")

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I have come across this anomaly before. By chance, do you have more than one body occupying the same space? In other words, do you two spirals or two rings? Is it possible that you already subtracted the spiral in which case the spiral and ring are not intersecting therefore the Done button will not appear.  
Just trying to offer some troubleshooting here.

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**Author:** ![lukasf](https://avatars.discourse-cdn.com/v4/letter/l/57b2e6/32.png) [@lukasf](https://discourse.shapr3d.com/u/lukasf)\
**Post date:** [May 31, 2021, 8:38am UTC](https://discourse.shapr3d.com/t/subtract-spiral-of-ring/13082/3 "2021-05-31T08:38:27Z")

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ok, got it. I had to increase the diameter of the spiral because it touched the inner surface of the ring. the subtraction would have produced a line on that surface, that is probably not allowed.

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**Author:** ![TigerMike](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/tigermike/32/32650_2.png) [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)\
**Post date:** [May 31, 2021, 4:37pm UTC](https://discourse.shapr3d.com/t/subtract-spiral-of-ring/13082/4 "2021-05-31T16:37:35Z")

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Is this what you are trying to achieve?

[https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/b/b586cdd7565a84ae64983c8e0a53f35a8f8eb7ce.MOV](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/b/b586cdd7565a84ae64983c8e0a53f35a8f8eb7ce.MOV)