I managed to clean the noozle of my RepMan 3d-printer.
* manual move -> get the bed down
* tool setup -> heat to 250°C to get the plastic to liquify (press button "up" serveral times)
* hold a needle with some pliers and poke into the 0.5mm hole in the toolhead
* start extrusion (press button "right" serveral times)
(I guess either the noozle was too high or too much plastic pushed out the noozle,
so it curled up in zig-zag -lines.)
I increased the temperature and extrusion-rate and got the bed higher during the print as the lines of plastic seemed to fall down from the noozle onto the object. Too thin and too cooled down when they hit the layer below to form a
After the first 2 layers of the round part the X-movement stopped. It seems that the
X-belt was too loose.