pros, I need your help!

I'm generally fairly happy with the outcome of this print, but can you see those tiny blobs of plastic on the side?

It leaves those wherever it finishes a layer. I assume this got to do with Z-hop and my retraction settings, but no matter what retraction-speed or -distance I choose, I can't seem to get rid of these artifacts.

Any ideas?

@fribbledom z-seams are tricky, I don't think you can fully get rid of them. You're fiddling with the right settings though.

@fribbledom I'm not a pro, but your slicer might have an option to do that on the inside. MakersMuse might have a video on it.

@fribbledom that's the seam, where leayers start and end. Retraction is problably less of an issue here, z-hop may be (see, plus "outwer wall wipe distance" and "coasting" if you're using cura, different slicers call those things different names. Oh, and you can control where that seam is (at least in cura).


Thanks! I played with the seam position indeed, but random only made the entire print appear worse (random zits here and there). I might try coasting.

@fribbledom That's a bad part for moving the seam position, but with other parts you could move it where it's hidden or doesn't disturb a mechanical fitting.

@fribbledom Are you running perimeters before the infill?


I am, otherwise my infill shines through the outer walls. I guess I could revert that setting change and just make the walls a bit thicker?

@fribbledom Hmm… then surely it's not a z-hop since it would be on the same layer moving to the infill, rather than moving up to the next one. What slicer? (no expert here!)

@fribbledom … and I'm using the wrong terminology -- I mean inner wall not infill


Hm, watching it print it still does look like it finished the layer with the outer wall where it leaves the blob. Maybe I need to record this and watch the print in closeup.

I used Cura 3.6 for this.

@fribbledom I came across something a bit similar ages ago, and I think I fixed it by fiddling with extruder temp. I was running too hot causing ooze


That was my first guess, too, since I also started to see a tiny bit of stringing. But I'm already running it at a low 195 degrees Celsius.

Weirdly enough, I can't see any visible difference for this filament between 190 and 215 degrees anyway.

@fribbledom try reducing the extrusion factor a little bit and see if that helps.

@fribbledom Sandpaper, 400 or higher grit? (Hoping I don't sound like a smart-ass.)

I mean, . . . high-grit sandpaper will get rid of those artifacts.

Many folks have strong ideas for pre-production solutions. If those don't work, you'll want a post-production solution.

@fribbledom you mean the broken vertical row on the OD? i'm pretty sure that's the start/end point for the wall layers. are you using cura?


Yeah, it's always the end point of each layer.

Running Cura 3.6.

@fribbledom have you tried the experimental feature in 3.6 that adds noise to the outer boundary? That might, at least, conceal it a bit.

@fribbledom this video discussing stringing contained some surprises for me regarding disabling z-hop. I think there was something about blobs as well but I can't check now. Maybe you have some time to watch it

@fribbledom apart from post-production with a sharp knife or sandpaper, you could try if your slicer has a setting to raise the z height continuously for the outer perimeter. In sometimes it's called "spiral vase" or similar.

@fribbledom Maybe add a tiny coasting distance of 0.1-0.2 mm at the end of a layer, if your slicer has that option? It helped a lot with zits on my prints.

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