slicing issue

[Bigred 0]

I'm new to cura and I've been printing for about 3 months with it and I've recently come across an issue when slicing a model, its seems to remove/ delete parts of the outer area of parts of the print on one file but then on a more complex version of the file it doesn't and the sizes are the same, its stumping me why it is doing it. sorry if not clear from the images. 

[gr5 2,170]

Your model is probably not manifold.  Are you willing to publish the STL file here?  if not there are lots of model services on the internet that check your model. Also what CAD are you using?  Different types of CAD result in different solutions.

 

Cura has an amazing plugin to test your model to see if something is wrong with it and can repair a very few of the many potential problems:
In the upper right corner of Cura click "marketplace" and make sure you are on the "plugins" tab and install "Mesh Tools".  Then restart Cura.  Now right click on your model, choose "mesh tools" and first choose
"check mesh", then "fix model normals" and "fix simple holes" to see if that helps.  Cura doesn't fix most issues so...

 

Also it might be that you have walls that are too thin.  As a general rule, walls must be 2X your line width.  But there are tricks to get around this if this is the issue.

 

[Bigred 0]

im using blender, and it is non manifold but the area it shows isnt where the errors occur.

ill try the plugins and i wouldnt think it the walls are to thin as the cannon prints fine in the first image.

thanks for the help and advice.

 

 es cannon part.stl

[Bigred 0]

the plugin and repairs worked cheers gr5

[gr5 2,170]

Blender!  @Bigred try this - the first thing fixes normals, not manifoldness.  Normals tell cura which side of every triangle faces air versus plastic.

 

Quote

if using blender - here's how to fix the normals in your model
I went into edit mode with the object in Blender 2.83 and pressed "a" which selects all faces / vertices / edges, depending on what select mode you are in. The entire object should be highlighted. I then went to "Mesh" (see images), went to the "Normals" section, and selected "Recalculate Outside". This probably will not fix any edges that are not merged, but it will fix the faces that are inverted on the object. 

More about creating printable files with blender:
https://www.sculpteo.com/en/tutorial/prepare-your-model-3d-printing-blender/