A "wound" on surface

I noticed this "wound" on the side of round objects (I'm printing my first experiments, not an expert) and I can't imagine what is causing it. Maybe calibration, but where/what?

I'm sure you may help me better :-)

It seems to be on every round object and always on the same side, let's say between hour 7 and hour 8 on a clock if you watch the printing surface from above.

I can't see anything similar on square objects.

Thanks

Zzzz might need to Randomize Z start points (layer change), but even that can produce undeZirable Z artifacts.

Edited 1 time(s). Last edit at 06/26/2016 10:43AM by MechaBits.

It's probably subtler on square objects because it's starting the perimeters at a corner. You may be able to tune this some with coast settings depending on your slicer and firmware, you can change its appearance by switching between inside-first perimeters and outside-first perimeters, and you can make it a series of points rather than a line by switching to random perimeter start points, but the nature of FFF is that there will generally be some kind of evidence where the extrusion starts and stops.

As above, it's the seam where the head starts and finishes each line. It's normal, and yours isn't particularly bad - actually, pretty good.

Single line would be better, I'd be more interested as to why the stair step was coming from, Software or Z, or elsewhere?

I use simplify 3D and I've been trying to minimize z scar recently using the settings coast, retract, extra distance on restart and wipe nozzle. I have next to no Z scar anymore.

The Z scar is essentially the pressure that has built up in the nozzle being released, even if you are not doing a printing move. Coasting in S3D (not sure on other slicers) stops the extrusion before the end of the line so the pressure releases the filament.

What are your coasting - retraction - wipe settings in Simplify3D?

Try upping your Z jerk and acceleration in firmware. This will help make the layer change much faster, and reduce the scar.

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Master Tinkerer