japs

Hello, I'm currently printing on a (sigh) Geeetech A20 using (yey) Cura software. I've been experiencing these lines in the outer walls of my prints for some days now, and i've tried to tweak almost every parameter to non avail. It looks like some layers are under extruding while others pop out; doesn't seem to happen in a cyclical manner, just an indented line every now and then. Retraction and coasting are activated since i'm printing 2 parts at the same time, although the same thing happens in a single piece print (with these switched off) If anyone has had this issue before can please give me a hint on what to look for? checked bowen extruder calibration keeping the printer safe from environement changes and on firm surface Using Geeetech black PLA bed temp. 55° nozzle 190° (best results so far) print speed 80 mms wall speed 40 mms layer height 0.15 in. layer heigh 0.15 retraction 3.5 mm ret. speed 65 mms coasting volume 0.08 min. ammount 0.8 coast speed 100% compensate wall overlaps (inner + outer) true all of above been tested in a ±5 range (or in small values for millimeters) Thankyou in advance CFFFP_divano 2.gcode