after checking almost all settings, voltages, after cleaning the extruder gear (some amount of abs grinded in the teeths)… after changing both peek isolators and nozzles (I was in despair) I tried a thing I read on another post (not my idea): I freed both ptfe tubes from the printer (1st and 2nd extruders) and let inside them some drops of rice bran oil via push/pulling in their holes a wet abs 1.75 wire piece. The general idea was to add some lubrication.
AND IT WORKED!
The original post told to use something like canola or canoila oil… after a little search I realized it was not toxic having an high “smoke point”; keeping this in mind I found rice bran oil has one of the highest smoke point temperature: by far more safer for my purpose. I found this oil in the food store among other food cooking (or dressing or frying) oils. It is very good to: it avoids cholesterol buildup, it’s tasty but “light” and very good to fry your favorite dishes…
This is my ricostruction of the phoenomena:
After long periods of work (plus long periods of inactivity I add) the inside of PTFE tubes keep some spot of ABS dirt: this ABS traces help to stick to the ABS wire adding friction distributed forces: the extruder push the wire in the curved PTFE tube but this friction eats literally almost all the push effort from the wire insert side up to the hotend: there in the nozzle the push force becomes too small and the nozzle clogs (not really being clogged)
Now the clicks are very very very (help me to say very) rare. I didnt’ change any firmware or Cura Repetier nor Simplify3d setting.
I add this thing too: to free the “not really clogged” nozzles frome the excess of material I do not dismount them from the printer: I take out only the top connection of the PTFE tube and preheat the nozzle; as soon as it’s hot i push a calibrated pin (d 1.7 mm) from top to down pushing out abs.
You can find them from moldmaker friends or buy it on internet: search for “ejector pin” diameter 1.7 mm. It seems to me much simple than dismounting the nozzle each time to clean it with a torch.
It worked (for me)
My actual problem is: how to dual color extrude with simplify3d? See you in the right post.