Ridges and stepping in my prints
From the picture, this doesn't look like an X or Y axis problem.  I wonder if it is a problem with the Z-axis positioning?
I don't have any specific suggestions, but I would start by, with the printer off and cold, manually turning the Z-axis motor(s) to assure that the movements are smooth and without any binding.  If the movement is smooth, then with the printer powered on, try some Z-axis movements, up and down, both listening and feeling for excessive vibration or jerkiness.
What may be happening is that the Z movement is binding for several layers and causing the flexure in the Z-axis to bend upward, permitting some plastic to extrude but forcing it into a wide bulge.  When the Z axis finally snaps upward, the build layer is too far below the nozzle, so the plastic does not bulge outward and necks down until it builds a base again.  This repeats.
It could be an electrical problem with the Z-axis drive rather than a mechanical sticking or interference, but you will feel that, too, by doing slow Z-axis movements and watching carefully, listening for irregularity, and feeling for any jerk or stutter.