Bad printing - extruder issue?
My 3+ years Prusa Mini was working perfectly until lately.
First layer calibration works well, the printing seems to be good, then it looks like purging is stopping for while - take a look at the pictures.
I cleaned the printing head, re-calibrated and it happened again.
I start suspecting the extruder: firstly because Prusa support guided me to tighten the screw, and also because the problem is bigger with certain filaments.
1- what do you think? Any ides?
2- How to calibrate the screw? The manual states it has to be flush with the plastic, but nothing is said about fine tuning.
3- What is the effect over tightening? less purge?
4- what is the effect of loose tightening/no tightening at all? I am not sure I understand the role of the screw.
5- Should I replace the extruder? Any recommendation for a non-Prusa better extruder? (perhaps with built in sensor?)
Thank you
RE: Bad printing - extruder issue?
Go with the Bondtech IFS extruder or the aTrianglelab clone. The only update I wholeheartedly recommend for the Mini. I have it on my two Minis, and never had to change the tension of the extruder screw again, which was a constant with the stock extruder.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Bad printing - extruder issue?
Go with the Bondtech IFS extruder or the aTrianglelab clone. The only update I wholeheartedly recommend for the Mini. I have it on my two Minis, and never had to change the tension of the extruder screw again, which was a constant with the stock extruder.
Sounds good, yet I wonder about the "again" - so you had to tune the tension once? I am concerned about the tuning.
RE:
"Tune" is giving it too much credit. I just screwed the screw in and backed it off a couple of turns or so as per the Bondtech instructions. It's been years but I know I didn't go through any tuning process.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Bad printing - extruder issue?
The problem was solved by tightening the idler screw.
Although the online database ( https://help.prusa3d.com/article/idler-screw-tension_177367 ) states to align the screw with the surface, I had to tighten it more. I guess it needs more pressure on the filament (is it so?).
The user guide doesn't state how to calibrate it, or what are the tradeoffs of the different tightening options.