Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
Hi there,
hoping someone may have some insight with this. I've modeled a building in 3D (free online SketchUp in browser) and brought it into Prusa Slicer to export the gcode so I can print. However when I press 'slice now' big horizontal gaps appear in the model, this happens regardless of whether there is supports or not.
I have tried adapting the model and creating new files, but the same issue keeps happening. On some occasions, I have rotated the model on the plate and the gaps move around the model. I'm not sure what the issue is. It has only happened recently and not sure if it has anything to do with the upgrade to Prusa Slicer (2.8.1+MacOS-x64). Attached are some photos to show the model and what happens when I hit 'slice now' in Prusa Slicer.
Any help is much appreciated!
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
It's very difficult trying to diagnose from screen grabs, zip the stl and 3mf files into a single zip file and attach here, I'll try and have a look to figure out what the problem is and others more knowledgeable than me might also be able to have a look
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
Well you can see from the screen grabs that there is a yellow warning triangle next to the model indicating it has issues. If you hover your mouse over it the pop up should tell you how many and of what type. You can also see purple edges and dark green surfaces on the model. Purple edges are a visual indication of mon manifold edges and the dark green surfaces usually indicate a problem with the normals.
Basically your model is broken.
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
Yes, there have been notifications that say things like 'layers between 12 and 25 have issues' but no more detail than that or how to resolve them. I've rebuilt areas and created new files but it doesn't seem to make a difference.
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
Hey thanks! I can't export 3mf from SketchUp online but here's the STL
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
Ah SketchUp. Notorious for not generating manifold models. If you hover over the yellow triangle to the left of the model in the tree list view (don't even need to slice it), the pop up will tell you that Prusa Slicer has repaired 406 reversed facets and 268 backwards edges.
However the model still has 379 open edges. An open edge means a non manifold model. If you don't know what that means then you have much to learn 🙂 Basically no manifold models are difficult for the slicer to slice. Essentially every edge coloured in purple is open, not joined to the edges next to it. And the really dark green areas are also broken such as half the top feature (which 'Im guessing you used some sort of mirror function on to get one half which is why one side the normals are wrong). All the little windows are open, the 'walkway' outside has no surface, you have some zero thickness surfaces etc.
If you were using the windows version of PS you would have access to the right click option of Fix by Windows repair Algorithm. Unfortunately you are on MAC and that's not an option. I've attached a fixed version for you but you need to either figure out how to generate a watertight model in SketchUp or drop it.
Personally I would drop SketchUp as a design option as its not very good at producing models for 3d printing.
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
thanks for all that! Ye for example on the top of the model, that small section on the roof was copied and mirrored. Is there another free program you could suggest that is better than SketchUp for doing this kind of work?
RE: Prusa Slicer (2.8.1+MacOS-x64) Big Gaps in 3D model when I attempt to 'slice' model
I use Fusion 360. Free version limits you to 10 active models but you can switch between active and inactive anytime so I just switch off the ones I am not using at the moment. There is a bit of a learning curve but it is worth it