what is causing this mistake?

[spiruline 2]

Hello,

I am giving my first steps with my new Ultimaker, and I am trying to learn from all you.

I have noticed this pattern alway in the same area of different parts:

http://cl.ly/image/1j181E383x12

I am using PLA and Cura with the following parameters:

Layer height 0.2

Wall thickness 0.8

Enable retraction: yes

Density 60

Print speed 80

Printing temperature 230

All parts have about the same diameter and are printed in the same area of the platform, I am not sure if that has something to do..

Any hints will be helpful

Thank you in advance

[tomnagel 80]

I'd say there's not enough plastic coming from your nozzle.

What filament drive mechanism do you have? Maybe it slips. have you tried tightening it?

I think your temperature is rather high, most values I see here in this forum are between 200 and 220.

[spiruline 2]

Thank you for the answer.

I have the latest (as from last week) Ultimaker, so I assume it comes with the latests dive filament. I'll try to tighten a little bit and print at 200-220.

Most of the times the walls are pretty smooth. What surprises me, is that the mistake always happens in the same area.