... depending on mechanical properties this could be "normal" ... you'll need a pretty stiff and accurate mechanical setup and superior extruder-controlling to get it "smooth" without lines or ringing.
Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]