SketchUp - Non-manifold object

Hi,

I've just received my Robo3D and successfully printed a test-print from thingiverse. I've now designed my first (very simple) object in SketchUp that I'd like to print, but Repetier says that it's "non-manifold", and the Slic3r-result consequently looks nothing like my original SketchUp-model ...

The model *looks* fine in Sketchup, i.e. there are no visible open surfaces. I've tested the model with the checks of the "3D-printing-tools" extension in Blender and it also tells me that there are some non-manifold faces, but doesn't highlight the issues in the model. I used the push/pull tool to create a raised surface in SketchUp, maybe that's an issue? I'm usure how to solve this, some advice would be much appreciated !

Thanks,
Nick

 

It may not be an issue with faces being too close. It is complaining that there are faces inside fully enclosed spaces (from my understanding of the term). And where this isn't an issue in a normal model it has been known to confuse slicers and 3d printers.

You may want to look at Netfabb Basic (free, nag version). It has done a nice job of fixing a lot of issues that even Blender fails to point out or fix right.

 

Yes looking at the part. You are placing two objects overtop of each other without doing a boolean union. So between the Lock in the cylinder on top and the cylinder below you have two faces that are considered "inside faces."

This is causing your issue.

 

Hi Ben,

thank you very much for your answers! I had already tried Netfabb Basic yesterday but the "auto-repair"-feature didn't actually do anything, the error persisted. I thought non-manifold faces were equal to "holes" in the model, but with your explanation, it makes much more sense (faces in enclosed spaces). I've since recreated the model from scratch in SketchUp without inside faces and this time, it worked perfectly, I've already printed the model successfully !

Thanks again for your help and for taking a look at the file!

Nick

 

In blender use the 3d printing tools to check the model. If you switch to edit mode then the list of errors will turn into buttons that can be used to select the problem objects and fix them.

 

Have to try the 3d printing tools in Blender. Haven't made it that far. I've personally been just using it as a box/geometric modeling tool myself. Then bring it into Netfabb basic and doing repairs.

 

Blender has a very steep learning curve, but is exceptionally powerful. It is not a dedicated cad tool so has some weaknesses compared to them. One area I've found it weak is measuring dimensions on a model. However I'm sure there is a plugin for it somewhere. Is is free and a great tool for rendering and animation.

 

This is the only discussion I've found on it: http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Modeling/PrintToolbox and http://vdorchester.hubpages.com/hub/How-To-Make-Models-For-3D-Printing

Not seen anyone do a video on it.

 

The first link is the blender web site and about all the formal documentation I could find as well. I had to start even more basic and get an understanding of what a normal is ( the direction of a face) and understanding what is a non manifold edge. There are some good sites for this , just do a web search.
I would suggest others get a grip of these concepts early as it will make modeling easier and understand why things might not be printing properly.

The Boolean functions provide the ability to manipulate objects with intersection, difference and union function. I had to drag out some of my high school math learnings to remember. They can get a bit out of whack in blender if the normals are not correct.

My son and I just finished modeling the assassins creed game apple of Eden. Took some effort to learn the program. We printed it on the schools makerbot. I am eagerly looking forward to being able to print at home.

 

Another tool (forgot until I was using it again) that is helpful in cases like this is the "Mesh Lint" plugin. You can check out the video at: http://cgcookie.com/blender/2013/07/23/addon-mesh-lint/

It has an option to show you manifold edges, tris, star joins, etc. Which may cause oddities in some surfaces. The two of them together make a nice error checking system in Blender, and it goes a long ways from skipping Netfabb as a generalized workflow step.

 

This post explains all about non-manifolds and how to fix them. Check them out:
http://3dprintingninja.blogspot.com/2014/07/non-manifolds-your-worst-nightmare.html

 

New software coming out to help.

http://3dprintingindustry.us6.list-...a38ff902659605b718&id=394dbc7129&e=1c6f3185d0