Help- Trying to make a shelled object- cannot use union tool

Can someone review my file? I am trying to make a shelled object but I can’t use the union tool on my model, I used Solid Inspector and Cleanup to inspect my model and both said my model is perfect. I don’t know what is wrong. If any one can help please leave me your email I will send the file to you…Thanks a ton.

Why not?

You can upload the model to this website or to the 3D Warehouse and provide us a link or to some third-party cloud drive, again providing us a link. That way you can benefit from everyone’s opinions, and everyone (who wishes) can participate.


Here’s a breadcrumb for the upload icon.


Here…Thanks!Octagon 3.6.skp (1.2 MB)

Here is the file…Thanks!!! :blush:

You just have a group nested in another group. Explode one and you’re golden.


umm so I exploded and this is what its showing me after I selected the outer shell tool :frowning:

Hmm. I think I’ve missed something here. You’re running outer shell on a single solid?
Explain a bit more what you are trying to do please.


Yeah, I am trying to make it shelled, with a wall thickness of 5mm or so. It is going to be 3D printed as a ceramic object, so the inside’s got to be empty. Thanks :blush:

I think you misunderstand what the shell tool does

How can I make this thingy shelled?
Is there a tool I can empty the inside?

Is this what you want. I’m sure others here are more expert than me when it comes to 3d printing.


Omg!!! Thank you! I think you got it right, but the object is not sectional. I want the object as is but the inside empty, with the shell 5mm thick. Thank you so much for drawing this!

Well, you drew it, I just copied it, scaled it and moved it.


I believe you would need to reverse the faces on the inner wall of the shell. Face backs (in this case a lovely pink) should face into what can be thought of as the “solid material.” Someone trapped in the inner cavity would see face fronts.

This is more than simply an aesthetic consideration: many 3D printers use face fronts and backs to define “inside” and “outside,” or maybe “solid” and “empty.”


Also look into the plugin called JointPushPull if you plan on doing this a lot.

For a simple shape like that just use follow me on a suitable profile.

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If you print it with a ceramic material, you should have a hole in it to get the powder out of it. See the guidelines for that material at your printing provider…

Hi, yes, so that is why I am trying to make this thingy shelled/hollow, is there a tool in sketchup can help me do so? I tried using the follow me tool but it won’t let me…And I don’t feel like drawing a new one from scratch either :confused:

All needed steps and plugins are mentioned in the answers before. You can modify the simple follow me steps suggested by @Box e.g. to make a hole in that thing…

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