Prints on an Ender 3 Pro using a standard printing profile results in layer shifting or over extrusion. I can’t figure out what the problem is. I tried reducing the flow as well as print speed but nothing really changes. Any thoughts on the XYZ cube test print below?
This isn't what folks usually refer to as "layer shifts" - those are generally permanent (for the rest of the print) and don't correct unless you get an equal opposite-direction shift, and are caused by things like a stepper motor skipping a step, a belt skipping a tooth, or the print surface shifting on the bed.
Your problem looks more like excess play in the positioning, particularly on the X axis, likely due to a very loose belt. If so, it will manifest differently in different layers due to the geometry and the last direction of motion.
It's also possible that it's Z wobble, where the toolhead experiences a Z-coordinate-dependent displacement in the X and Y directions due to irregularities in the Z motion system. This could be a bent or nicked lead screw or nut, flat spots or other damage to the V roller wheels, or debris on the aluminum V slot extrusions that the V wheels are rolling on.
The fact that the top layer came out very clean and consistent makes me actually suspect it's the latter - some sort of Z wobble.
