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Seam gaps in bigger nozzles  

New Member
Seam gaps in bigger nozzles

I have a .6 nozzle and PrusaSlicer always slices with a big gap at the layer change:

 It's big enough that it is clearly visible in the print:

I've tried everything, but i can't seem to get rid of this. Retraction, wipe, overlaps, layer changes, flow rate, pressure advance, etc.

Googling a bit, there seems to be a lot of people having this when changing to bigger nozzles, but I can't work out what it could be.

I assume it's trying to avoid blobs at layer change, but it seems it's too enthusiastic.

If anyone has any idea, I'd be extremely thankfull.

Posted : 19/06/2021 6:27 pm
Trusted Member
RE: Seam gaps in bigger nozzles

AFAIK it's normal to see this gap in the slicer and it does not indicate that there is actually a gap that's going to be voluntarily printed. It's so that you can see the seam position in the preview. It's more visible with larger nozzle sizes, but you can still see it with smaller nozzle sizes if you zoom in far enough.

I don't think it's possible to ever get rid of the z-seam entirely, although in your picture it is indeed quite visible. In addition to fine-tuning things to reduce the visibility of the seam you might also want to play with the seam position setting / seam painting feature to put in in a less conspicuous place.

According to the Prusa KB, the extrusion multiplier and linear advance are the things that affect this most. On my MINI+ the linear advance is not configurable (I think) but it might be on the MK3 series or whatever printer you might have.

Before messing with linear advance though, I'd try calibrating my filament with a procedure such as this one (says "stringing" in the title but it covers more than that, as the intro enumerates), rather than fiddling with values blindly trying to get better results. I don't know if you tried a procedure like this before or you went with the "trial and error" approach, but that link might be a good start in any case:

Another good resource to fine-tune extrusion multiplier:

I'm not an expert but that's what I'd try first! Let me know how it goes.

This post was modified 4 months ago by fortinmike
Posted : 20/06/2021 3:45 pm
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