# Create irregular hollow spaces inside a shape

**URL:** <https://discourse.shapr3d.com/t/create-irregular-hollow-spaces-inside-a-shape/22460>\
**Category:** Modeling Questions\
**Created:** [November 13, 2022, 5:33am UTC](https://discourse.shapr3d.com/t/create-irregular-hollow-spaces-inside-a-shape/22460 "2022-11-13T05:33:50Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Iliketrains](https://avatars.discourse-cdn.com/v4/letter/i/b5ac83/32.png) [@Iliketrains](https://discourse.shapr3d.com/u/Iliketrains)\
**Post date:** [November 13, 2022, 5:33am UTC](https://discourse.shapr3d.com/t/create-irregular-hollow-spaces-inside-a-shape/22460/1 "2022-11-13T05:33:50Z")

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Simple question but I am obviously not searching the right words -

I’m making a rough wireframe of a multi level train carriage that’s going into other software for me to sketch over.

I want to carve out interior spaces inside my carriage that do not join up with the outside, and the extrude tool does not seem to let me do it (adding shapes inside the carriage, then selected them but shapr does not let me use the extrude tool in that context) and the hollow tool just hollows everything evenly which is not what I want.

I have tried several different tools and videos and cannot find this use case covered anywhere.

What am I missing?

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**Author:** ![Matt\_the-Rathje](https://avatars.discourse-cdn.com/v4/letter/m/49beb7/32.png) [@Matt\_the-Rathje](https://discourse.shapr3d.com/u/Matt_the-Rathje)\
**Post date:** [November 13, 2022, 7:42pm UTC](https://discourse.shapr3d.com/t/create-irregular-hollow-spaces-inside-a-shape/22460/2 "2022-11-13T19:42:42Z")

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Hello Iliketrains,  
Try the following:

- Hide the body you want to subtract from
- make an extruded body from your sketch
- Unhide the first body again
- select both bodies and use the subtract-command to subtract the second body from the first.  
HTH  
Cheers Matt

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<div class="post-metadata">

**Author:** ![Iliketrains](https://avatars.discourse-cdn.com/v4/letter/i/b5ac83/32.png) [@Iliketrains](https://discourse.shapr3d.com/u/Iliketrains)\
**Post date:** [November 19, 2022, 11:30pm UTC](https://discourse.shapr3d.com/t/create-irregular-hollow-spaces-inside-a-shape/22460/3 "2022-11-19T23:30:59Z")

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Thanks Matt, that works.

I haven’t done modelling or cad sketching in a few years and I know what I want to do, but shapr3d does everything slightly differently 😊

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**Author:** ![Matt\_the-Rathje](https://avatars.discourse-cdn.com/v4/letter/m/49beb7/32.png) [@Matt\_the-Rathje](https://discourse.shapr3d.com/u/Matt_the-Rathje)\
**Post date:** [November 19, 2022, 11:41pm UTC](https://discourse.shapr3d.com/t/create-irregular-hollow-spaces-inside-a-shape/22460/4 "2022-11-19T23:41:45Z")

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No problem, you are welcome!  
I am happy to know that you are back on track on your road to success with Shapr3D, again! 😉  
Do not hessitate to place your questions here - I’ll be here to help amongst all the other cool guys in the shapr-community.  
Cheers Matt