Nozzle clean fails every time, using PLA
Hi all:
After many hours of building, getting X and Y to finally pass calibration, I can't get the printer to print anything. The printer always fails to clean the nozzle.
I'm trying a print in very fine detail (I don't recall the wording) in Prusaslicer.
What exactly is the printer trying to do when it's trying to clean the nozzle? I see the z axis moving up and down and tapping the printer bed then moving over slightly and doing this again a number of times before it fails. I also see that the printer head assembly moves left and "bangs" the left side of the printer a number of times before it tries the nozzle cleaning process.
Any clues anyone has would be very helpful. Is my layer height too low, are the thumb screws holding the nozzle assembly to the printer too loose, is there something else I should be looking at?
Thanks in advance.
RE: Nozzle clean fails every time, using PLA
the printer is trying to get consistent responses from the automatic levelling load cell in the middle of the hot end heatsink
to the best of my knowledge the tapping is to displace any filament crud under the nozzle, before mapping the build plate surface
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Nozzle clean fails every time, using PLA
That's very helpful.
Any idea how much difference is allowed for this process to pass?
Should I try re-calibrating the load cell again? The instructions say to tap the tip of the nozzle, should that be a soft tap, a hard tap? I often fail the tap by missing the nozzle or by not being quick enough.
How tight should my thumb screws be to keep the shaft to the nozzle from moving just enough to cause this to fail? I worry that if I over tighten the thumb screws I'll damage the hollow shaft.
RE: Nozzle clean fails every time, using PLA
Hi James,
I just tightened the thumb screws firmly, with my fingers, no tools.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
I begin to suspect that most cleaning fails are caused by oozing filament which in turn is caused by damp - the moisture boils and expands the filament inside the nozzle. Manually cleaning the nozzle first *might* help.
Cheerio,
RE: Nozzle clean fails every time, using PLA
Could it be a sensitivity issue with my load cell sensor? I've had trouble with the tap feature to calibrate it only working sometimes.
My nozzle is clean, no "bumps" on the print bed, I've tried two different rolls of PLA, I've even performed the sensor tap using my print bed instead of my finger.
I noticed when I tap the nozzle on setting up the load cell that the graphic bar on top of the screen only moves part way.
RE: Nozzle clean fails every time, using PLA
After spending time in chat with Prusa tech support it was discovered that during fractional rotations the left z stepper just sits and stutters.
Prusa is sending me out a replacement left z stepper motor. This is probably why I can't get the printer to pass the nozzle clean step, at least I hope so.
RE: Nozzle clean fails every time, using PLA
I'm a happy guy.
My left z stepper motor arrived this morning. I did the swap right after work, took me about 35 minutes. The printer is now printing!
I guess it pays to pay attention to what the stepper motors are up to.