PanPan

Hello Guys, I am currently studying the relationship between the filament and over/under extrusion. So I modified the gcode (increase/decrese E-Value) on the printer job on purpose, in order to make over/under extrusion. In the preview of printer job, that looks good. But when I printed it, the result is really strange. That printed not like in Preview. And I don't know why. Do someone have any idea? Or have experience of adding over/under extrusion on purpose. Many thanks in advance! Xinjian