3d Printing slicer fills needed holes

Hi, I’ve been designing a thing that has to circles that you can twist together. Everything looks good to me, but whenever i try to print it, my slicer fills in the holes at the bottom. I’ve tried using the solid inspector but it says its not valid for inspection. Can anyone help?

The holes it fills in are the ones in the picture of the bottom of it

For one thing you have faces reversed. You should not see any blue back faces on the outside of your model.

How about uploading the .skp file so we can take a look?

@DaveR improvedinsert.skp (199.4 KB)

Fixing the face orientation should take care of it. Try this.

improvedinsert fixed.skp (192.7 KB)

It worked! Thanks a ton!

You’re welcome. For your future projects make sure you have the face orientation correct. The white front faces should face air and the blue back faces should face the printing media.