On my latest print, which is basically a simple cylinder, an odd blob has appeared. I'm using an i3 with PLA 1.75mm, 0.4mm nozzle printing at 185 C. Layer height is 0.25. Printer has recently had calibration checked and all appears fine. Cylinder wall varies between 1.37 and 1.45 in thickness. The blob is 2.0mm diameter, and penetrates right through the wall. It is well clear of the layer transition.
