Hole in object slicing as solid?

[jamsessionein]

I have an object with two holes through the parts that were created the same way in 3d Studio Max. I'm amateurish at best with modelling, so I'm sure this is my fault, but I don't know how to fix it or to get Simplify3d to cooperate.

This is the part's .stl:

http://www.fusedcreations.com/adam/barrelplug2.STL

This is the model when loaded in Simplify3d:



This is the model after slicing. What? What happened to that second hole? Why is it getting filled in?

[TenKOhms]

I have an object with two holes through the parts that were created the same way in 3d Studio Max. I'm amateurish at best with modelling, so I'm sure this is my fault, but I don't know how to fix it or to get Simplify3d to cooperate.

This is the part's .stl:

http://www.fusedcreations.com/adam/barrelplug2.STL

This is the model when loaded in Simplify3d:



This is the model after slicing. What? What happened to that second hole? Why is it getting filled in?

Seems there are some missing triangles or surfaces on the part. If you do a cross section view of the object along the X-Axis then turn on the wire frame view, you can see that the left hole has an inner ring with wireframes whereass the one on the right is missing them.

Anytime the output seems funky and not what it should be, it's almost always likely that theres a problem with the STL file itself.

[Festus440]

Well I can tell you that it's a problem with the model.
It looks like many of the normals are flipped, maybe more problems.

I mostly just use 3d Studio for rendering so I'm afraid I can't tell you what went wrong.
Tried Netfabb and it just plugs the hole too.

[reddadsteve]

I use Blender for my 3D modeling and loaded your file. Blender has an option to look for non-manifold edges and it highlighted that there are three circle loops in the hole that you are having an issue with. On closer inspection it is fairly obvious that you wanted these loops connected but left them without connecting faces along the z-axis.

3D Studio Max should have an option for determining if an object is 'manifold' or 'watertight'. I'd suggest that as a beginner that you search their boards/help desk on that topic to learn how to clean up the model as you will undoubtedly need to learn this going forward.

Steve