Top infill has gaps

  • Printer Name: Prusa MK3
  • Pathio Version: 0.5.0 Beta 3
  • Filament Type: Prusament PLA

Important Slicing Settings: Default

Top infill has gaps.

Hi Jasper,
My best guess offhand is that your “Shell fill and perimeter overlap” is a little low. Try bumping it up a tad and see if your print tracks merge better with your perimeters.


Also, these kinds of curvy surfaces can be tricky for slicers to fill perfectly with rectilinear shell fill. Our work on dynamic tracking should solve this nicely (but that is a bit of a ways off).

Seeing this also with default Ender 3 profile/config. I will try adjusting shell overlap as instructed to see if it makes a difference.

Speaking of the Ender 3 config, I did some tests before launch and noticed some small gaps in top surfaces that weren’t obvious in Cura. I’m looking to do some more exploration to see if there’s something more systemic that we can fix, or if there’s just some slicing settings that need tweaking. We’d appreciate if you find anything out to let us know!

Same gaps on my Flashforge Creator pro, the rest looks excellent

Gabe, did another print with it bumped up to .7. Definitely headed in the right direction but still gaps on a couple walls. I’ll keep playing with it but I think this is the correct setting to be manipulating. Might just want to adjust the default setting for better results OOB.

Cool. Looking forward to hearing more from your experiments. The default is what we expect should be right, based off how we calculate where to physically draw the tracks, so I am hesitant to simply bump it up by default (though not opposed to if it seems like the right thing)

Seeing similar slicing issues but not quite the same. From what I can tell there is simply no gap fill. If this is known then I apologize.


Upping the overlap to 0.7 results in this.

As you can sort of see, this simply results in the solid top fill being laid down in these gaps, rectilinear. Given the very tight spacing however I would hazard a guess this would not print sufficiently, or at the very least, it would print very inefficiently. Given the rapid reverses in direction, it would likely over-extrude the top layers, compounded by the fact its also overlapping more with perimeters.

I’ve yet to fully setup the slicer for my machine and so have not printed a slice yet to confirm this.

You’re absolutely right that gap fill is a big issue with Pathio at the moment. Due to the way 3D offsetting works there are several small changes in the shell thickness, and these need to be filled up. These little holes don’t always fit a normal track in them, so sometimes they don’t get filled at all, which is very bad.

We’re working on a comprehensive solution called Dynamic Tracking, which will let us vary the width of extruded tracks (within acceptable bounds) so we can resize perimeters to fill in these holes automatically, or efficiently fill them with new tracks (as few new tracks as possible). For now, bumping up the overlap value is a good way to force shell-fill to work in these gaps.

But yes, it is a known problem and appreciate you pointing it out so we could explain where we’re at with it.