Good old 20mm test cube.
Still getting Z banding, better though.
Myself, and other Mendel90 owners, have observed that Bang-bang style heated bed temperature control can produce Z-related artifacts. We are switching to low-frequency PID temperature control and getting better results.
I have also noticed that using an enclosure reduced my banding as well. It might be a similar issue…
@Neil_Darlow does the bang bang method work by increasing the bed temp when the perimeter is laid down?
@cosimo_de_santis Well still having tightening the X & Y cables and printing isolators for the Z has help a lot. I am using a E3D with the 0.4mm nozzle on a @Maker_s_Tool_Works Mendel Max 2.0
@Neil_Darlow I am using PID control for the Bed, never drifts more than 1C, interesting thought, though not sure I personally understand the link there.
Oh and Printing in PLA, if that makes any difference.
Does this happen with all filaments? Would also help identifying if perimeter starts would be all in same place.
Z-Banding - that is banding caused by over constrained or misaligned Z screws - is most easily seen as “in” on one side of the print and “out” on the other side on the same layer. If you hold hte print up to your leadscrew, they should align nicely with the threads.
The “bang-bang” bed expansion caused banding dates back to at least the Mendel Max, and causes “bulges” that are “out” on all sides of the print.
@Jonathan_Haberman Bang-bang control is simple on-off control. It can lead to some flexing of the heated-bed PCB during the heating and cooling periods. This can show as thinning of some layers at intervals. PID control is more complex and results in near zero PCB flexing at working temperature.