Black blobs
Can anyone tell me how to stop the black blobs that like to appear in a print. Usually happens when I print with the PRUSA orange PETG. I have 2 MK3S and only one of the printers does this. The printer has a brand new 0.40 nozzle. Left several black places throughout a 5 hour print.
RE: Black blobs
Black filament is usually burnt blobs that have sat on the hotend for awhile and then drop off onto your print.
usually 2 possible things -
With petg liking to stick so much you might just have a bit stuck to the nozzle during printing which drops off later. Clean your nozzle before printing and if over extruding slightly might cause a buildup, so check your extrusion calibration for the filament you are printing.
The other possibility is you mention it has a brand new nozzle fitted, was this a replacement nozzle that you have fitted ? If so then it is possible that it isn't properly sealed against the heatbreak. This leads to molten plastic seeping through the threads until it exits, both at the nozzle and also upwards at the top of the heater block too. Check your hot end with a flashlight to see if you have any accumulated petg (might need to move the fan shroud to inspect). Lokks at both the top of the nozzle where it screws into the heat block and also on top of the heat block itself.