I had been printing quite nicely with colourfab filament then changed to another filament . the filament then was not extruding enough and some prints failed . i tried changing the tension on the feed wheel at the back but it didnt help so much . i tryed upping the material flow which seemed to help to some degree , 0.1 prints where easier than 0.06 on the 0.06 prints i upped the material flow to something like 300 % material flow .
i noticed the feed wheel would slip backwards when the prints failed , it looked like a retraction but at a place on the print where there was not a retraction .