I try to describe the problem better. I'm using:
- UM2 with firmware 14.01.2
- Windows 7 with Cura 14:01
A lot of layers are printed normally. At irregular intervals, the following happens:
The print head stops very short, the extruder motor clacks in rapid sequence 3-4 times. It sounds like normal under-extrusion due to too low temperature for example.
But that's not it.
Under-extrusion clacks each 1x in relatively regular intervals.
Here it only happens as described above and the extruder jumps within 1 second 3-4 times back. Then as normal printed with missing material. A gap in pressure occurs.
The best way to imagine it so:
There is a normal "retract", but the extruder motor does not pull back rather pushes front. That would be a possible explanation, and describes the effect at best.
This happens quite sporadically. Anyway, I can not detect a pattern.
Does anyone have a similar behavior observed?
The bad news: this effect i can see under 13.12 too :(