Gaps under thin features

[simonBR]

I'm having problems with slicing objects with thin features (ribs for example) on top of flat layers.

S3D slices the object in a way that under the rib there is an empty space. This issue does not occur in Cura.
This problem makes parts much weaker, as I use ribs for making the part more rigid an the bond between flat surface and the rib is weak.

My setting are (relevant ones):
-Infill 100%, rectilinear, 40% overlap, print every layer, minimum length 0
-Layer .1 mm
-Outline 2
-Extrusion width .4 mm

Why is this happening? How is this 100% infill if there are gaps in the worst possible places? Did I miss some important setting?

[dkightley]

Looks as if you have interleaved meshes....something I get all the time with my CAD package.

On the Mesh dropdown there's an option Separate Connected Surfaces. Click this.....and the number of entries in the model list will multiply. Now re-try the preview....and it will look better.

[simonBR]

Separate Connected Surfaces did not do anything.
I use Solid Works and the model is single body. This command should separate multi-body parts, so that each can be moved/modified separately.

The problem is that all of the top layers sections are split by the rib. The space between the top sections is then too thin to fit in the infill. Infill is generated properly where the thickness is increased (round section).

[billyd]

Try changing your layer height a little. For example if it is .2 change it to .19 and see what happens. I think there is a round off problem in this current S3D version that causes problems depending on feature dimensions and the layer height you select. At least that's what I've seen in many models. I can correct a lot of these slicing issues by going to an oddball layer height. I have no idea if this is what is causing your problem, just a hunch.

[smartavionics]

Hi,

I have already raised this with the s3d tech support some time ago and it has also been mentioned a few times on this forum.

The problem is simply that they don't run the top solid layers sufficiently far enough under the perimeters of features that are above the solid layer. If they only did what, say, slic3r does in this regard, the prints would be a) stronger, and b) have nicer quality top surfaces.

I have now gone back to using slic3r for those prints where this is a problem.

Cheers,

Mark

[dkightley]

The problem is simply that they don't run the top solid layers sufficiently far enough under the perimeters of features that are above the solid layer.

This thread discusses this issue:
viewtopic.php?f=9&t=3822
It was partially addressed in v3....but needs more work doing on it!