Nozzle cleaning failed?  

RE: Nozzle cleaning failed?

Printer Settings->Custom G-code->Start Gcode. Look for 

M104 T0 S{((filament_type[0] == "PC" or filament_type[0] == "PA") ? (first_layer_temperature[0] - 25) : (filament_type[0] == "FLEX" ? 210 : (filament_type[0]=~/.*PET.*/ ? 195 : 170)))} ; set extruder temp for bed leveling
M109 T0 R{((filament_type[0] == "PC" or filament_type[0] == "PA") ? (first_layer_temperature[0] - 25) : (filament_type[0] == "FLEX" ? 210 : (filament_type[0]=~/.*PET.*/ ? 195 : 170)))} ; wait for temp

You can change the 195 to something more suitable for your needs.

I actually changed my startup code to

M104 T0 S{first_layer_temperature[0] - 40} ; set extruder temp for bed leveling
M109 T0 R{first_layer_temperature[0] - 40} ; wait for temp

to set the temp to 40 degrees less than the target temperature, regardless of filament type. I've used this on my old Mk3s forever, with no issues, so I just moved it over to my Mk4s. 

Nozzle cleaning failed

Posted by: @tom-horsley

Just got some new Hatchbox PETG, and fairly frequently when I start a print, it will heat up the nozzle to 195, then poke the front left corner to do nozzle cleaning, but it will keep poking for a long time then say nozzle cleaning failed. If I raise the nozzle enough to see under it, I'll find a perfect little ring of PETG around the end of the nozzle, pull it off with tweezers and retry the print and it works fine.

Should I make a new profile for this filament with a higher or lower temperature setting for it to use during cleaning (where would I find that in the profile, I wonder)?

I also have lately the error "Nozzle cleaning failed" while printing PETG on the textured sheet.
Also I noticed during first layer calibration, some times a measuring point is repeated. It is not measuring on exactly the same  point but very close. But during calibration  no error message came.

I found the cause to be very small dots left behind on the print sheet during nozzle cleaning and calibration.
They are very difficult to see. I detect them by going over the print sheet with the spatula. You feel that something is still on the sheet.

Very careful cleaning, especially in the nozzle cleaning area of the sheet, so far prevented this error to happen again.

RE: Nozzle cleaning failed?

There is a Firmware Update today...

CHANGES IN 6.0.1

Japanese language support (MK4, MK3.9, MK3.5, XL)

Phase stepping fixes (XL)

Nozzle cleaning repaired (MK4, MK3.9, XL)

Stealth mode corrected (MK4, MK3.9, MK3.5, XL)