Blocked nozzle somewhere above hot end - any tips for clearing, or just buy another?
Hi
Printing white PETG I've had a blockage causing the printer to through the motions and thought it finished fine, but the top half of the job was missing.
The filament was jammed and unable to unload. I had to take the front off the nextruder to remove the filament and get the small pieces cleaned out. When I heat the nozzle I can get a needle up it a long way, and liquid plastic coats the needle, but I can't feed anything in to force that old filament through. The attached photo shows the filament is the full length of the nozzle, flush with the end. This is the standard 0.4 CHT nozzle that shipped on the Core One.
I was thinking of putting the nozzle in a vice and put a flame onto it to try to push this filament through manually, but wonder if the normally cold end is up to that heat? Or is this simply a lost case and just get another nozzle?
Very happy to hear other suggestions.
Cheers ! Geoff
White and pastel filaments are often tricky to print as they contain so much pigment that the melt can become a non-Newtonian fluid.
Open the extruder idler - you are going to feed directly to the print head ...
Heat the nozzle to at least 10° above the hottest printing filament you use.
Take 50cm or so of PLA and, by hand, push it down through the nozzle - it may take some force at first - if it does feed push the filament slowly at first then accelerate to as fast as it will go - finish by pulling the last few cm back out as fast as you can.
If it doesn't feed, you have a ruined nozzle.
Cheerio,
RE: Blocked nozzle somewhere above hot end - any tips for clearing, or just buy another?
I have the exact same issue with some white PLA stuck in a .4 hardened nozzle. Simply won't budge.
RE: Blocked nozzle somewhere above hot end - any tips for clearing, or just buy another?
Thanks @Diem - that's pretty much what I was trying last night and I couldn't get it to budge. The material in the hot end being so cooperative gave me hope I could maybe push some of the solid filament into the heat, but it's rock solid.
I've ordered a new nozzle, but since I have nothing to lose I will still try the idea of putting this in a vice and gently waving a butane flame over it to see if I can soften the blockage and nudge it further down with the blunt end of a 1.5mm drill bit. If whatever alloy the filament guide is made of doesn't survive the process, the whole thing was going in the recycling bin anyway so nothing lost 😀
White and pastel filaments are often tricky to print as they contain so much pigment that the melt can become a non-Newtonian fluid.
Thanks for confirming this. I wondered why I have challenges with white PETG I don't often see with the other colours, and wasn't shocked it was the white that played up this time. The datasheets don't show different settings so I'd thought it was all me!
Cheers, Geoff