I have moved the stepper pots both ways with no success and. PID autotune has been performed on the hotend
Thanks
Swap your extruder driver with another axis driver. Readjust pots. If ok, swap out your extruder. If you still have problem then your extruder is fine and pots fine.
What type of control board You could always swap stepper drivers from another axis to see if it changes anything
Switch the e and z before buying and see if it helps. E is most used and z is least used. If it resolves then you know before making any purchases.
FYI there is a patent on controlling flow with temperature ( by a big company… I think…)
Try reduing the layer height and increasing the extrusion width.
Sometimes the extrusion bead will whip around if there is too much space between the nozzle and the previous layer or the substrate. The whipping tends to be effected by that which it is being deposited on which would cause the pattern you are seeing. It is a sort of positive feedback loop where the phenomena perpetuates itself. Let me know if that helps!
Maybe a resonant frequency of the 4 springs that your build plate is mounted to, if you have a mendel prusa. Go to stiffer springs.
Not sure what happened here, but I hope this won’t be the last time you’re commenting here, @! It was a good input, so it must have been a mistake. Hope to see you around here soon 
if you have a Persa Mendel like mine your Wobble might be Frame make sure your frame is true and all your Belts and Pulleys are tight and your Z axis is stable Dragging easy fix is more bolts holding the Z screw in place no oscillation.
You’re looking for something with a periodic oscillation and the extruder’s the most likely culprit. You can do a visual inspection by releasing the guidler and removing the filament so you can view the hobbed bolt/gear. Set the temp of the hot end and get the extruder to extrude 100mm (without filament). Watch the gearing for wobble and watch the hobbed bolt/gear for any unusual movement. The chances are you’re getting movement somewhere that isn’t rotational.
What kind of Mount do you have your extruder could be causing the hot end to wiggle in the Mount Or a loose bearing or rod but something that moves in a very repeatable fashion I would guess a off center gear or pulley
have you found a resolution to this problem?
having a similar problem
It is the errors in rounding of the steps in your x y steppers. My mendel does the same when setting steps x=166. Setting to 160 does fix it but my print is not to scale. I can use cura to scale up the model to make up for that.
no that is never the case. my mendelmax has 55 steps per mm and still works perfectly
I took a look at the forum post, from the pictures you seem to be having a different issue than I was having. In my case, I believe my calibration print was printing too slow (like 10mm/sec). whenever i did a regular print and printed between 30-60mm/sec the ripples were not very visible.
In your case, it looks like it is a combination of printing too fast for your particular printer and z-screw wobble.
You might want to print out some z-screw stabilizers and slow down your prints and do a quick test after you have made those modifications.
Good Luck…
Found a year old post with a similar problem of mine! did you discover anything? I’m having this issue and I found out a way to make the problem more evident: vary the extrusion multiplier by small amounts. This should give you different inclinations of the effect, from diagonal to vertical and horizontal. I initially thought I was seeing z banding, then I changed the extrusion multiplier and siddenly I got slightly inclined banding! Clearly, the extruder is oscillating proportionally to extrusion rate, creating the pattern.