Ok so i've been having this problem for about 2 months now. I've been researching, asking, and getting my hand on it trying to fix it, watching different videos and so on the internet. This is my third post about the same issue on the forums but this time im gonna explain absolutely everything ive tried and what i found out is causing the issue, and maybe with that you might help me solve it. Because i still cant.
So i have an ender 3 that i bougth about 2 months ago, first prints were ok, then ive started having underextrusion because of the "combing on skin " option on cura , i solved that and now this happens. I get extremely under extruded layers , wich look to form the exact same patterns. I've printed the same exact model twice and the under extrusion started at the same exact height for both of them. I thought it was a prpblem related with the z axis, but then i noticed something with the extruder was wrong. The extruder knob, with the motor, and everything is working, except for the feeder wheel, wich works intermintently, sometimes it moves inwards when the extruder is extruding and sometimes it just doesnt move. I've tried everything. I've loosen, thighten either the extruder arm, the spring, changed its tension by adding a 1mm print attached next to it, and nothing seemed to work.
When i adjusted the bolts of the extruder, the estepper starting slipping and missed steps, also the gear of the extruder started grinding the filament. When i loosen it , the feeder wheel worked intermintently losing extrusion for the print.
I've also dismantled it several times to see if theres any clog preventing the extruder to push the filament on the nozzle or something, lowered the heat bed and actually bought more nozzles to replace the older ones with. I've tried as well different profiles and different softwares, different temperatures, different speeds (even at 20mm/s) and about 7 different filaments. None of these worked.
I've ordered a metal extruder to replace the stock one with but i need to start printing now, and i just cant seem to make it work !
The tension on the extruder arm is driving me crazy and seems like no mechanical adjust will be capable of solving the problem.
Thank you for your time and i really hope you have an advice for me !