I have already been wondering at long time why gray extra cylinderic object appear into Luban when I try use right extruder for support structure or mesh painting. I have try ask at earlier how that should be carried out so that the extra object wouldn’t appear into Luban. Is it possible to use dual extruder thus, another extruder would only produce support structure. I have tested that problem on Linux and Mac. The phenomenon happen on both OS. Below there is picture, in which the extra object show.
That’s the purge/prime tower. When printing with two filaments, one nozzle is always idle. This tends to ooze and to lose pressure. The purge/prime tower is intended to wipe off oozed material and to build up nozzle pressure again after changing nozzles. It is possible to switch it off, which is OK if you can live with a few imperfections in the print. It saves a bit of plastic to switch it off, but you may either end up with wrong color specks in wrong places, or with smaller areas of underextrusion (which may be countered by modified retraction settings, i.e. “extra prim amount”).
