CIM

Using Cura 4.0 with an ANET A8, uprated to Marlin. I noticed the same problem on recent prints. I was printing a 28 mm diam disk, 3 mm base thickness, using 0.2 mm layers (later 1.5 mm, but fault still present). The part ended up 3.5 mm thick, with the lower side being a 1 mm disk of reduced diam (by 1.2 mm) and of much lower infill resolution than the rest of the layers. I have recently performed a full levelling / alignment process, and am happy that the problem is not mechanical. Material flow is smooth, temperatures at 200C (extruder) and 60C (bed). The workpiece is sticking nicely to the bed. I can't see anything in the (Cura-produced) GCODE which is an obvious cause. I have tried tinkering with the profile to see if there is an easy cause, but nothing obvious. The only other clue is that the 3 mm base is supposed to have absolutely vertical edges, but examination shows the part growing in diameter slightly as each layer is printed. By the time it reaches the top surface of the disk, it has crept up to 28.4 mm. Does this sound familiar to anyone? CIM QLS50b.stl