# Union doesn't work

**URL:** <https://discourse.shapr3d.com/t/union-doesnt-work/33502>\
**Category:** Modeling Questions\
**Created:** [August 30, 2024, 4:45pm UTC](https://discourse.shapr3d.com/t/union-doesnt-work/33502 "2024-08-30T16:45:27Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Xeni](https://avatars.discourse-cdn.com/v4/letter/x/2acd7d/32.png) [@Xeni](https://discourse.shapr3d.com/u/Xeni)\
**Post date:** [August 30, 2024, 4:45pm UTC](https://discourse.shapr3d.com/t/union-doesnt-work/33502/1 "2024-08-30T16:45:27Z")

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Hi!  
I’m overall a very happy user, but today I stumbled upon an issue that I can’t resolve.  
I’m using Shapr3D on Mac and have multiple objects. I need to union everything into one but it just doesn’t work.

Please check the video:

https://www.loom.com/embed/984a8c869bc944508983ad71e8c80b23?sid=c1c8fca1-cbd7-4d68-8cea-98d6f6af7b36

The lower “platform” is intersected with the upper “boxes” because I’ve read that intersection actually helps with the Union operation. And I’ve had other projects before where it really did help. However, in this instance it does not.

Please help!  
Thanks.

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**Author:** ![pHp](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@pHp](https://discourse.shapr3d.com/u/pHp)\
**Post date:** [August 30, 2024, 5:48pm UTC](https://discourse.shapr3d.com/t/union-doesnt-work/33502/2 "2024-08-30T17:48:54Z")

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Can you share a shapr3d file for further inspection?

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**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [August 30, 2024, 6:47pm UTC](https://discourse.shapr3d.com/t/union-doesnt-work/33502/3 "2024-08-30T18:47:55Z")

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He Xeni,

It looks like many of the objects share an edge with another object. That won’t union because you would be making a non-manifold body, and Shapr3D is preventing that from happening. If you make the cubes (and other) just a tiny bit larger without moving their centers, I think you’ll have success. You can’t simply scale everything, as that will keep those shared edges. Does this work for you?

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**Author:** ![Xeni](https://avatars.discourse-cdn.com/v4/letter/x/2acd7d/32.png) [@Xeni](https://discourse.shapr3d.com/u/Xeni)\
**Post date:** [September 1, 2024, 1:31pm UTC](https://discourse.shapr3d.com/t/union-doesnt-work/33502/4 "2024-09-01T13:31:24Z")

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Hi Bob,  
Thanks, that actually worked! I see the logics now.  
Really appreciate your answer! I will keep this in mind further.

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**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [September 1, 2024, 1:56pm UTC](https://discourse.shapr3d.com/t/union-doesnt-work/33502/5 "2024-09-01T13:56:23Z")

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You’re welcome, glad it worked out for you!