Hello,
I have a prusa i3 pro b from geeetech. I have some quality problems with it. You can have a look on the below pictures and let me know what do you think it is the problem:
https://www.dropbox.com/s/hewpedzapw..._3723.jpg?dl=0
https://www.dropbox.com/s/2srwazvspd..._3724.jpg?dl=0
https://www.dropbox.com/s/k90njujdxl..._3725.jpg?dl=0

I know that nozzles temperature does not fluctuate for more than 2 degrees Celcius. The Z axis are also calibrated. The filament that I currently use is Esun PLA but the issue occurs with almost any filament.