Print: banding every 5 layers

[animetown9]

Hi

Does anyone have this problem.
i3 pro with sangupolol 1.3. repetier, windows 7.
Nozzle 0.4mm, layer height 02.m speed set to 30mm/s for all.

Every print I do, and every 5 layers I have banding on the object.
I double check the banding is about the same size aas the Z-rode thread.
Is it because the z-rod thread is to big, or the firmware is not setting right.


Anyone has similar problem if yes, how did you fix it.

Thank

[zhangxueyou]

Could you please take a photo?