Zerial

Using Latest CURA, printing a polygonal beam with some holes (handguards for airsoft, in specific.) it prints OK with all the other parts, but some area shows strange outer wall behavior. Never encountered this kind of problem with any other models before... Strange wave-like patterns CURA preview of the problematic layer in between current settings GCode of the print attached. shortened version for faster print also included. The original object is in perfect straight beamlike shape. it does not show anything wrong in other parts, but only in between two screw holes, where there is no support (needed) at all. Tried re-slicing, re-printing with the other PCs, printers, but have the almost same problem... so it should be modeling problem, or a wrong slicing option choice, I suppose. Any idea removing this? 7inch mlok.gcode shortended.gcode