Editing stl issues

[pseudotheist 0]

I am trying to edit an stl file.  If I import it into blender and re-export it the object image looks o.k. in cura, but when sliced (at 65%) generates extrusions and voids where they did not exist in the original stl.  In the attached images, you can see some of the added material right in front of the fins. Any ideas on how to fix or prevent this corruption, or editing software alternatives to blender for linux which would inport STLs more reliably?

Reinforced_Shark_v2.0_A.stl BlenderTest.stl

[Slashee_the_Cow 267]

Working backwards from an STL isn't a great choice (if you have a choice). Blender is also notorious for putting out poor quality STLs (since it's not designed for that sort of thing).

 

In Cura, you could try going to Mesh Fixes > Maximum Resolution and setting it to something low (like 0.1) to see if that helps.

 

FreeCAD can import STL files and turn them into editable objects, but without knowing what you're trying to do, I'm not sure how good it would be at it (plus it has a learning curve nearly as vertical as GIMP).

[jaysenodell 13]

Hey now… some of us think FreeCAD isn’t that hard. 

 

FreeCAD can make an editable object from an STL, but you’ll need lots of memory and ram. Especially if it’s a large or complex STL. I would say you have both. Expect it to run an hour (or multiple hours) on the various import and transformation steps. Save after each (to a new file) and expect crashes due to out of memory conditions. Increase swap save when that happens. You’ll have the same problem with any effort to go “backwards” from STL to planar solid. 

Edited January 16 by jaysenodell

[pseudotheist 0]

Thank you!  I've muddled through GIMP, and was muddling through Blender anyway, so more than happy to muddle through FreeCAD.  It has certainly turned out that the way to do things in FreeCAD was very different than the way I expected to do them, but so far it appears to be able to do what I want it to do, and saved me hours of headaches w/ corrupted Blender STL exports.

 

I did have some processes crash on my little 2-in1, but it turns out those weren't the processes I needed to run anyway.