Cleaning up a model

I have a 3D print model that I can’t make manifold. It is basically a hollow ball with internal structure.
I have used SU Solid Pro, Solid Inspector, and Cleanup3 but I still have 2 pieces with 3 faces (yellow) and I cannot find them. Obviously, VERY short lines. I also have lots of blue (extra lines) and distorted faces that neither extension will fix. Sometimes multi colors exist on top of one another making life more unbearable.
I tried fixing the STL in Repetier, but it eliminated my internal structures and made it so that the slicer would fill the inside. Solid Inspector wants to do the same thing - make the inside internal faces so the slicer fills it. Netfabb did the same thing.

How do I find the 3 or more faced lines (yellow)? (only 2 of them left)
How do I fix the blue lines?
The distorted faces do not create a manifold problem.

I have a previous version that was successfully printed but I had to add more internal support structure.

We really can’t answer your question unless you upload a file showing the issues! Too many possibilities of what is wrong.

OK, but I didn’t upload because I wnat a general answer I can use on other models - as I have this problem regularly. Sometimes it works itself out, sometimes not.

name build exploded top (2.5 MB)

sorry, I guess you need the SKP.

name build exploded top (2.3 MB)

The general answer is to not build models with issues that prevent them from being manifold solids. As you can see, that answer isn’t worth much!

what about now ?name build exploded top (2.1 MB)

You have some impossible juxtapositions of outside (i.e. front) and inside (i.e. back) faces. See the attached, where I have set an obnoxious green shade to the back face color. In the top wall, there are inside faces and outside faces toward the interior of the same wall (look at the underside of the letters vs the inner face of the wall and the struts)! SketchUp (and the slicer) can’t figure out what is interior vs exterior!

08 AM

Edit: ON revisiting this model, I didn’t see the same reversals as in my screenshot. Then I remembered that I had run SolidInspector 2 before creating the section and taking the screenshot. It found about 12k faces it says are reversed, so I let if fix them. That caused the specific case I showed in the screenshot. But that was the only problem SI2 found, and after letting it fix that it says the model is ok even though SketchUp still does not believe it is manifold. That leads me to think that there is a small flaw somewhere - most likely a self-intersection or a place where a lot of faces meet - that is causing SketchUp and the slicer to be unable to decide what is inside vs outside. I’ll look again…


that isn’t the problem with the letters. I don’t know why si2 thinks all those lines are redundant but if I try to delete them it breaks the model. If I ignore them, as I did in my first iteration, it eventually gave me a purple image and printed almost fine. It needed a little more support inside. That is what this version has but I can’t get it to complete. I posted another issue that may be effecting this regarding follow me. It doesn’t want to build with the expected diameter.

If you fix the reversed faces with si2, it becomes a solid and the slicer fills the whole inside - not good. The inside of the walls are the only inside faces. I don’t know how to create it so it won’t do that but it seems I had the same issue previously with another model. I don’t remember how I fixed that one.

SUCCESS. it was the way I built the bottom.
see this assoc. issue.


What is the print technology you plan to ues? What you see on the PC is virtual but what you print makes it physical and of course gravity now comes into play and reason for this question.?
How much has the item already been scaled- up,? I measure the base thickness BIG!
The way you model the item is prone to the small segment size issue at the pole on the " lid" . Suggest you reduce the segment count drastically and consider flat on lid like bottom to avoid trying to inter face with a sphere if possible.
I would be tempted to model and print seperately but, since it appears to be some type of pressure vessel that may be incorrect.
When asking for help it is good idea to state if possible what the ultimate use is.

thanks for the feedback.
it is scaled x1000.
The issue was mating the top and bottom. I modeled each separately - not a good plan. But I am not a SU expert (yet).
I finally realized follow me was a lot better plan. It came out perfect. I probably could have used fewer segments given that it is x1000, but it was an arbitrary decision.
It has supports inside. The goal was to make it print well but be a light as possible. It is printing now - for the 4th time. I guess I can use the fails for storage bowls. Total filament @ 1.75 is a hair over 25M.
Now the support printing is the issue. It was almost OK with fewer supports, but I had to watch it. Not for 6 hours…Getting the supports as small as possible makes it sloppy to print. But as long as they do their job, I don’t care what the inside looks like.
It started out in 3 pieces that required post process glue. I figured a one piece print would make it structurally sounder and more water proof. It is a float for a Drone.
The bowls hold water with no leaks, so this should be perfect if the supports work.
Total weight will be 75.25g. I would like it less but that should be float-able. Now if it will fly.

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