8
$\begingroup$

I've just tried to make some small labels with embossed lettering. Base is 1.5 mm, with letters and a perimeter protruding by another 1 mm. After printing, I realised that Cura is not giving me a top layer, all I get is an inner and outer wall for the perimeter and the lettering:

Screenshot showing missing infill in top layer

The base is OK, with 4 layers, but there is no infill at the top. Presumably there is a setting that I've missed (I can appreciate that maybe this is a detail to the slicing which is model dependant). Layers are 0.2 mm, top and bottom set to 4 layers.

I had walls set to 1.6 mm, (4 layers) and the wall features here are 1 mm (i.e. 2.5x the nozzle). The features are solid so far as I know, not drawn as a hollow.

I found a relevant bug for Cura: https://github.com/Ultimaker/Cura/issues/1303 (and I also understand a workaround now, just need to write up an answer).

$\endgroup$
  • 1
    $\begingroup$ Did you activate "vase mode" or something similar? $\endgroup$ – Tom van der Zanden Dec 2 '16 at 22:41
  • $\begingroup$ Not seen any options looking like that. Other prints are OK, it's just narrow walls. $\endgroup$ – Sean Houlihane Dec 3 '16 at 0:00
3
$\begingroup$

What is your source model? Typically this "missing layer" effect happens if the source has a wall thickness less than the size of the extruder nozzle selected. Cura will view that part of the model as non-printable.

Meshmixer and TinkerCad (among many others) will allow you to set and change thicknesses in the model.

|improve this answer|||||
$\endgroup$
  • 1
    $\begingroup$ It came from TinkerCad, its just solid letters, and a solid base with a cutout (to get the perimeter wall). So I'm expecting a wall thickness of 1mm (and a 0.4mm nozzle). So, yes, I guess the question is if I want 0.8mm+0.2mm void, or a 50% over-filled centre. $\endgroup$ – Sean Houlihane Dec 2 '16 at 14:23
2
$\begingroup$

What is happening here is that Cura is struggling with the quantised extrusion width. This behaviour can be improved in the slicer, they have a issue tracked here https://github.com/Ultimaker/Cura/issues/1303 and 2.4 beta has improved it.

There are some pictures in this answer which show how Cura 2.3 slices a rectangle of increasing width. I got nothing at the nozzle width, then a pair of overlapping lines up to twice the width (which I assume will be over-extruded due to the overlap). For anything wider than simply two sides, the result depends on the number of walls requested.

  • One wall results in 100% infill for small regions (regardless of the infill setting). This is good, but maybe 1 wall is not apropriate for the whole model.
  • Multiple walls seem to prevent the infill untill there is space for pairs of walls. So width of 3x nozzle has a gap. Small tweeks to the nozzle size can maybe push this quantisation point about, if 1 wall is not a good workaround.

For rectangular geometry, it's worth trying to quantize small parts in 0.8mm increments. For curves, setting 1 wall shell might be better.

|improve this answer|||||
$\endgroup$
1
$\begingroup$

Try Cura 2.4.0-beta2: there is option named "Fill Gaps Between Walls" under "Shell" settings, set it to "everywhere". In stable Cura 2.3.1 this option is missing.

|improve this answer|||||
$\endgroup$
  • $\begingroup$ Yes, I already noted that 2.4 beta gives some improvements in my answer... $\endgroup$ – Sean Houlihane Feb 21 '17 at 13:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.