PVA extrusion issue

Hi everyone,

Is going wrong with PVA in dual extrusion
After one minute printing first layer, PVA filament slips out from the extruder
I noticed (before filament slip out) the hobbed gear partially strip the filament

1.75 PVA - 200/205° (in slic3r settings I used 1.77mm, multiplier extruder at 0.8)




Please help me!!

II had to design an extruder from scratch for my printer to solve that problem. I shared the design here, maybe you can find some cue to fix your extruder too.