Perimeters dependant Banding

[PicoTreed]

Hi All,
I'm experimenting a strange banding behaviour.

In the attached image is showed 15x15x5 mm cube printed with a white TPU.
From left to right you can see print results from same print parameters, except for setting 1, 2 and 3 perimeters.
The print with just 1 perimeters is almost perfect, while setting 2 or 3 perimeters lead to a variable banding artifacts.

Well, does anyone have any ideas?
Could it be related to the this? -> viewtopic.php?f=9&t=14038

I exclude the hypothesis about some hardware Z problem, due to the perfect print on the left.

Thank you!

[S3D-Alex]

Could you post a Factory File for this? It seems unlikely that the other issue you link to is related to this but I would be happy to take a look and give my opinion. There are a lot of physical and material dependent factors that are more than likely affecting your prints here. The bulges appear to be where the start and stop points are so my immediate guess would be the excess heat here is causing the deformations.

[PicoTreed]

Thnak you Alex for your quick reply!
Here you can find the factory file.

[S3D-Alex]

Thanks for the File! You said this was TPU right? If so I would suggest turning retraction off completely for this part. There are no open spaces or islands it should need to travel across and elastic filaments usually do not retract and prime very well. Alternatively, you could also go to the Advanced tab and turn off 'Force retraction between layers'.

Not allowing the retractions here should hopefully allow the extruder to not dwell at the start/stop points very long. It would also probably be helpful to switch from using Optimized start points to random. This should spread out these points a bit more which again will hopefully help distribute the heat build up around the part more.