# Part of design will not subtract

**URL:** <https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185>\
**Category:** Modeling Questions\
**Created:** [April 12, 2020, 7:46pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185 "2020-04-12T19:46:00Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![NetWhiz](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@NetWhiz](https://discourse.shapr3d.com/u/NetWhiz)\
**Post date:** [April 12, 2020, 7:46pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/1 "2020-04-12T19:46:00Z")

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Can someone explain and show me why the missing eyelashes do not want to extrude and subtract from the cap? I had several and was able to cope ones that did work and subtract with this (not a real solution). No matter what I do I can not get it to remove the last few eyelashes from the cap.[Mask Cap - Optometrist.shapr](https://discourse.shapr3d.com/uploads/short-url/6UMfCkNyRLfHZM2akNipdgTHcjs.shapr) (6.6 MB)

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**Author:** ![JasonBelec](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@JasonBelec](https://discourse.shapr3d.com/u/JasonBelec)\
**Post date:** [April 12, 2020, 8:10pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/2 "2020-04-12T20:10:19Z")

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Looks like a normals issue. Not sure if Shapr3d handles that.

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**Author:** ![NetWhiz](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@NetWhiz](https://discourse.shapr3d.com/u/NetWhiz)\
**Post date:** [April 12, 2020, 8:31pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/3 "2020-04-12T20:31:59Z")

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A what issue?

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**Author:** ![JasonBelec](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@JasonBelec](https://discourse.shapr3d.com/u/JasonBelec)\
**Post date:** [April 12, 2020, 8:36pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/4 "2020-04-12T20:36:32Z")

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Normals, face out from surfaces in 3d. Allows visualization and rendering. Could be something else. I was able to do a quick test in another app, bring into Shapr3D and had the exact same error so it easily repeatable. Hopefully the powers that be will address it.

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**Author:** ![Victor\_Shapr3D](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/victor_shapr3d/32/3502_2.png) [@Victor\_Shapr3D](https://discourse.shapr3d.com/u/Victor_Shapr3D)\
**Post date:** [April 13, 2020, 9:41pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/5 "2020-04-13T21:41:51Z")

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Hi, we are looking into this, seems like an issue with the patched STL body. I will get back to you as soon we find a way around it

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**Author:** ![NetWhiz](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@NetWhiz](https://discourse.shapr3d.com/u/NetWhiz)\
**Post date:** [April 15, 2020, 5:18am UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/6 "2020-04-15T05:18:48Z")

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Well, after is remade the cap I tried again. The lashes did not all want to subtract. Now, with a simpler design, I can not get it to subtract still. Are there error logs with more detail as to what the problem is? [https://www.dropbox.com/s/6217sfdyt0thgg9/Eye%20Take%202.shapr?dl=0](https://www.dropbox.com/s/6217sfdyt0thgg9/Eye%20Take%202.shapr?dl=0)

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**Author:** ![Victor\_Shapr3D](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/victor_shapr3d/32/3502_2.png) [@Victor\_Shapr3D](https://discourse.shapr3d.com/u/Victor_Shapr3D)\
**Post date:** [April 15, 2020, 12:06pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/7 "2020-04-15T12:06:12Z")

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Every workaround we tried is not working and this seems to be associated with the Imported STL file.  
For future designs I will recomend that you import parts in STEP, IGES OR X\_T format.

STL format is not the best for further design editing, it’s more of an output file format.

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<div class="post-metadata">

**Author:** ![NetWhiz](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@NetWhiz](https://discourse.shapr3d.com/u/NetWhiz)\
**Post date:** [April 15, 2020, 1:59pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/8 "2020-04-15T13:59:58Z")

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If I had the choice, I would have. Unfortunately, all that was available was STL files. What about the latest version I uploaded?

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**Author:** ![MatDemers](https://avatars.discourse-cdn.com/v4/letter/m/3ec8ea/32.png) [@MatDemers](https://discourse.shapr3d.com/u/MatDemers)\
**Post date:** [April 15, 2020, 2:23pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/9 "2020-04-15T14:23:03Z")

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In your most recent version, there is a sketch plane with what looks like an eye. What are you trying to accomplish with that? Is that what you are trying to subtract from the mask cap? Not sure what the end objective is here.

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<div class="post-metadata">

**Author:** ![NetWhiz](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@NetWhiz](https://discourse.shapr3d.com/u/NetWhiz)\
**Post date:** [April 15, 2020, 5:00pm UTC](https://discourse.shapr3d.com/t/part-of-design-will-not-subtract/7185/10 "2020-04-15T17:00:53Z")

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Correct. Trying to subtract part of the image from the cap.