I have been using my Ultimaker 2 for about a year now, but I have recently been having trouble with prints that have hollow interiors such as pipe or tube shapes. When printing, the object starts to have an odd spiral lip that forms. It looks like the part just doesn't stop or start properly causing this issue to form on each layer. There are usually 4 to 5 spiral spaced out evenly rising together through the part. This only seems to happen internally, but there is a little bit happening external to the part. In addition to this spiralling, the prints have become hairy. I have tried changing plastics to see if that was the problem. I also regreased the rods and relubed the z screw as well as tightened the pullies. I have not started printing with any new settings that I wasn't using before. I am printing with ABS at the following settings (I will post more details if needed): Nozzle Temperature 248C Layer height 0.1 mm Shell thickness 0.8 mm Nozzle Size 0.4 mm Travel speed 220 mm/s Bottom Layer speed 40 mm/s Infill speed 50 mm/s top/bottom 35 mm/s Outer 35 mm/s Inner 45 mm/s Cooling fan 50% The parts I am printing have a 2.5 mm wall thickness.