Inconsistent vertical walls on a Robo 3D R1+ I'm trying to troubleshoot an issue with my 3D printer (Robo 3D R1+). It cannot print vertical walls well any more. Here is a picture of what it looks like:



The walls are very inconsistent. To correct this issue, I've tried:


Changing the nozzle
Tightening the hotend (to remove wobble)
Dehydrating the filament
Using brand new (good quality) filament
Printing faster &amp; slower
Printing hotter &amp; cooler
Trying different slicers (Ultimaker Cura &amp; Simplify3D)
Putting on a belt tightener


The 5 motor drivers are all new as well, but this was already happening before I changed them.
Mmm... you've tried lots of obvious things. I don't have a printer the same as yours, so my help is generic. 

How about a thorough check of extruder and filament path, since it may be just inconsistent filament feed? I've seen something similar happen when the filament reel was not rolling freely. Less likely, but also check that the frame is still solid and nothing has come loose.