Slicer reports 1000s of errors not seen in Cura; Render is missing big chunks


Brand new to Slic3r, I've been using Cura for a while, so not sure is happening. I tried to load this Knight model into Slic3er (v1.2.9 running on OS X), and it's reporting "Manifold: auto-repaired (11430 errors)", and the model looks incomplete. Hovering the model with the mouse shows more details:

Slic3r Screenshot

Preview mode shows supports holding up the head, so I don't think it's just a screen rendering issue. But I loaded this same model into Cura earlier today, and it worked just fine; I've printed the resulting GCode. So I believe the model is fine. I wanted to print using Slic3r and compare the results.

Is this a known issue with certain types of models? Not sure what to try next.

Jason Clark

Posted 2017-01-29T00:21:44.513

Reputation: 243

3The model is not fine. If it was "fine", Slic3r would not have this issue. Cura does some magic to fix it. Try running it through an STL repair program. – Tom van der Zanden – 2017-01-29T08:02:20.173



Cura and Slic3r are very different programs. You will not get the exact same print between the two. I find that of late slic3r will try to fill holes when older versions do not. So even versions will not behave the same. I will say I have less issues with simplify 3d, but the price is very high.

Following. When this happens I attempt to repair the model. There is obviously some unresolved issues in the model. I use Netfabb which has been exported to this online tool.

Really though. I would ask for my money back ;-)


Posted 2017-01-29T00:21:44.513

Reputation: 2 913

Actually, that model author only charges for printed models - if you log in to Shapeways, you can download his STLs for free (and some others, but not all). So, I got what I paid for :D Will check out Netfabb, thanks! – Jason Clark – 2017-01-29T18:12:11.217

-1 for Netfabb; it outputs 3mf, not stl. 3mf not yet supported by slic3r. – Jason Clark – 2017-01-29T18:28:20.623

@JasonClark Netfabb will export STL. Lots of people use it without problems. – Sean Houlihane – 2017-01-29T20:11:32.953

@SeanHoulihane perhaps it's only the hosted version at Could not find any options, only a Download icon upon completion that produced 3mf. Will check into other versions, thanks!

– Jason Clark – 2017-01-29T20:15:49.957

The full software Will export as stl. Not saying that it's default format is stl but will export as. Also Unless I did the wrong link the online toolshould be stl format only. – StarWind0 – 2017-01-30T04:49:34.377


The problem with the model is that of the basic elements that make up the model (fundamentally these are triangles), you'll find some that either cross over, or some that don't touch. This is called non manifold geometry.

The way this comes about is often by the designer dragging part of a model (to re-size it) in a way that one face of the model crosses into or out of another face. It is very common, and some of the slicers handle it better than others. Sometimes a tool can make a good job of repairing the model, sometimes it has to be fixed manually.

In fixing the model, a tool will be able to ignore small gaps and overlaps (which is fine, they are often below the print resolution anyway). Different tools will be more or less successful, it looks like your model here is a bit borderline for automated fixing.

Sean Houlihane

Posted 2017-01-29T00:21:44.513

Reputation: 3 622