Little blobs forming during solid infill

I don't know if it's clear from the picture, but this just started happening and I have no idea why!
This little blobs that starts to form during solid infill, some just get kicked out but others stays on the way and when the nozzle starts the next layer it bumps on it and ruin the whole print.
I took a long time watching the process and it's like the nozzle is dragging over the previously printed line and eventually the "extra" plastic starts rolling, getting bigger and bigger.

I'm printing with ABS at 220º, heated bed is leveled and printer is supposed to be calibrated. Although I always had some issues with solid infill in large or very small surfaces and was correcting it in Slic3r advanced settings with no extra problems as this one

Anyone ever had this problem before and can explain what is going on???

You need to check your extruder calibration. If the steps per mm are correct, then lower your feedrate, you are overextruding.

Increase some the temperature because in the picture there is evidence of bad interlayer adhesion.

Yes, the extruder is calibrated and I used to print at 230º but the nozzle was scorching the previous printed line.

It was my understanding that the feed rate regulated "how fast" things works. So I can get over extrusion symptoms due to too high a feed rate on E???
It would explain a lot.....

This is my current settings on Marlin:
DEFAULT_MAX_FEEDRATE {500, 500, 3, 25}
I'm using a Greg Wade extruder, what would be a better value?

Well, 25 sounds right.... What's your acceleration and retraction acceleration settings and what's the print speed?. If your settings are right, the next thing to look at will be the Z axis.

Well....I lowered it to 20 and it's so much better that I'm actually impressed.
I'll try to go lower and see what happens. I'll also have to reset all the extrusion values on Slic3r too

Thanks a lot Sir.

When you ask for printing speed what exactly do you mean?? I read people talking about it, but never found it as a value on Marlin or a field on Slic3r.
These are my complete setting as you asked for. Had to slow down quite a lot the acceleration and jerk, but I intend to raise it up slowly after fixing all this quality issues.

#define DEFAULT_AXIS_STEPS_PER_UNIT {79.3, 79.3, 4000, 1050}
#define DEFAULT_MAX_FEEDRATE {500, 500, 3, 20}
#define DEFAULT_MAX_ACCELERATION {2000, 2000, 100, 700}

#define DEFAULT_ACCELERATION 1300
#define DEFAULT_RETRACT_ACCELERATION 300

#define DEFAULT_XYJERK 10.0
#define DEFAULT_ZJERK 0.4
#define DEFAULT_EJERK 1.0


[manual.slic3r.org]

I get the image from Google since I don't use that slicer. The top portion is the printing speed setting in the slicer.

All your firmware settings look perfect, I'm surprised that you have quite conservative values. Most of the people that have issues printing have way too high settings.

Keep the jerk at 10 or max 15. The standard 20 reduce a lot the print quality.

Edited 1 time(s). Last edit at 05/13/2015 01:37AM by ggherbaz.

Thanks, lets see how close I can get from those values.