Hello All, Long time reader, first time posting, so thanks for all of the information that has been gathered here already! I have been having a troubling issue with my Ultibots D300VS+ that I think I have finally narrowed down to the Titan Aero extruder having a repeating pulse causing a visible defect in the print surface. If you are interested in the long version of how I came to believe the extruder is the source of the problem, see the link below to the thread on the Duet forum where they helped me narrow it down: https://forum.duet3d.com/topic/7135/help-with-strange-diagonal-banding-on-ultibots-d300vs/15 That thread can be summarized by the picture attached showing the distance between the print defects changing with layer height, leaving everything else the same. My theory is that there must be some repeating mechanical issue in the extruder causing a slight pulse at a constant volume of extrusion and creating the artifacts you see below. I have already checked the bearings (although I ordered some new ones to be safe), hob alignment, and gear mesh (including lubricating the gears with some heavy grease) and everything is in order. I have also tried different stepper motors, micro-step settings, temperatures, nozzles, and filaments but the defect remains constant. Oh, and before you ask, the extrusion width is within 0.01mm of what is requested by the slicer (Simplify3D) no matter what I ask for, so I am pretty sure it is not an extrusion rate calibration issue. If anyone has any ideas about what I should try next, I would greatly appreciate the guidance! Happy printing.