Regional Blob on Seam

Hi!

I'm wondering about this printing issue I get.
Below is a pict of my print focusing on seam.

I'm using slic3r and set the seam to aligned. It's understandable that the seam is not perfectly aligned for the entire print, but what I wonder is why the behaviour is quite different for different area.
The far side of the picture is the first layer.

This part of seam is quite good. Just a little bulge, still smooth.

This part, on the lower layers, is worse. The bulge is quite blobbing, even the perimeter got pushed for a while along the line.


I'm using prusa i3 model printer btw, with a bowden extruder. My retraction setting is 4.5mm, 60mm/s. The perimeter speed is 80mm/s with acc of 1500mm/s2 and max jerk of 5mm/s

The problem is the pressure stored in the long bowden cable when doing infill, is transferring to the extruder when doing perimeters.

Set your infill speed and extrusion width to be the same as your perimeter speed and extrusion width.

That looks like the Z scar you get when the layers change in the same XY location every time. I have problems with this... Try either enabling or disabling the "retract on layer change" option. Also speed up retract length / speeds, or Z acceleration / speed. I guess the trick is to get the Z axis to move as quick as possible so there is no time for the nozzle to leak.

Edited 1 time(s). Last edit at 01/14/2016 02:27PM by Montiey.

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Master Tinkerer

Also there is a way to get it to change layers on an inside part that is not visible, but I can't remember how.