The UP 3D Printer extruder is notoriously known for getting very hot around the extruder gear. This heat softens the filament and the gear begins to chew out the material causing a nozzle jam. For the best results we recommend printing PolySmooth using the ‘Fast’ setting in UP Studio with 0.15mm layer height.
While not necessary we have also been testing an UP Mini 2 mod which will redirect the model part cooling fan towards the extruder gear. When completed we will release the file on Thingiverse.