frequent nozzle cloggs after stopping prints
Hello,
I have an mk4 and am having some strange issues with what I'm fairly sure are clogged nozzles.
First off, I am totally blind. As a result, 3d printing for me means a fair bit of trial and error. I frequently need to start prints, then pause the printer to make sure that things are printing correctly.
I'm noticing that fairly frequently, I will run into issues with the first layer not sticking to the bed. Cleaning the bed in these situations doesn't help. If I heat the nozzle to around 250 for a few minutes, then use a wire brush to clean the tip of the nozzle, I usually get a small blob of filament out. After that, the printes will stick correctly again.
This seems to happen about every 4 or 5 prints. More often if I need to frequently stop and start the printer in the middle of a print.
I'm printing with Polymaker Poly Light PETG Silver, using the Prusament PETG profile. I started off using a 0.4 nozzle, but recently switched to the 0.6 nozzle. I'm still having the same issues with the 0.6.
Does anyone have any suggestions as to what could be happening? Should I be using different temps for the Polymaker filament?
Is there some way of having the printer do a longer nozzle purge at the beginning or end of a print?
Any suggestions would be appreciated.
RE: frequent nozzle cloggs after stopping prints
I am not sure, but these clogs may occur because your printer sizzles the filament during the pauses. With the "new speeds" of MK3.5 and above come new problems. One of them is: if things go slower than expected, there will be issues with the filament (uneven prints or clogs). If the print pauses, the heat remains for some time.
I don't know how long you inspect the print, but even some seconds cooking the filament on unloved temperatures may leave residues in the nozzle.
When the issues only occur after some prints, you could try to purge the nozzle before or after every print. You can use the start or end gcode to do this. Heat the nozzle about 10-20 degree higher than your last used filament, extrude with high pressure a small amount of filament, disable the temperature and continue extruding a thin line of filament until temp reaches MK3 temps (about 20 degree lower than your temp). Then unload the filament.
You can instead frequently let the MK4 do a cold pull between your prints.
Printing PLA and PETG at the same time? See the Guide for MultiMaterialSupports ----- Ejecting Buffer cassettes is not satisfying? May the Fork be with you!
RE: frequent nozzle cloggs after stopping prints
Thanks for this. Do you have a sample gcode for this? I'm not all that familiar with the specifics of gcode yet.