Extruder Problem
Hello,
I am having trouble extruding filament to complete prints. https://imgur.com/a/TmYFcsa . So I took a needle and put that through the nozzle while it was heated up and it seemed to clear up the issue for a couple prints but then the issue returned worse than before. I am currently able to unload the filament without issue through the Prusa menu on the LCD. I have tried cleaning the nozzle with a brass brush in case a stray piece of filament was stuck. I have heated up the nozzle to 260 C as per recommendations on the support site but now I am at a loss of what to do next since nothing has fixed it.
As a side note I did notice some "powder" residue, not sure if it was powder, on the wheel that loads the filament. I cleaned that off and still nothing. There does seem to be a little friction when I insert the needle into the extruder hole but again, a thin bit of filament will extrude out when I load filament.
I have been printing without issue for almost a month and this is the first time I have hit a snag I couldn't really fix. Any help would be much appreciated
Re: Extruder Problem
Time to learn how to do a COLD PULL ...
With filament already in ...
Let the printer cool down (extruder temp should be less than 40c).
Open the Bondtech Gear door.
Set the nozzle temp to 85c ...
-- keep a steady upwards tension on the filament until it releases from the nozzle.
Trim the filament; reload normally.
Sometimes more than one cold pull is needed to clean the nozzle. Also, sometimes filament fragments fall down the PFTE tube and jam inside the heat break. Only a thorough air out of the extruder will help this. A can of air, and after a cold pull stick the air nozzle into and around the PTFE and blow for a bit. Sometimes you'll need to pull the nozzle do clean dust from the PTFE. Carefully follow the manual to do a nozzle removal. Heating is required - and you must loosen and tighten the nozzle at temp.
Re: Extruder Problem
You mention a thin powder near the hobbed bolt drive. Are the teeth partly blocked? This happens when the temperature in the hot end is too low and the filament is not melting. The drive turns and chews the stuck filament. Clean with a toothpick or similar.
To reduce the chances of it happening again, raise your printing temperatures for that filament by 5 to 10 degrees in the slic3r profile and re-slice your model(s).
Bill
Tagaytay City, Philippines
Founder member of Philippines Prusa Printer Owners FB Group
Sponsor Pillars of God Academy in Bacoor
Re: Extruder Problem
I just looked at the images ... the brim is okay, yet the body of the print shows signs of extreme under-extrusion. A plugged nozzle won't do both.
What slicer are you using? Where did you get the profiles?
Re: Extruder Problem
I just looked at the images ... the brim is okay, yet the body of the print shows signs of extreme under-extrusion. A plugged nozzle won't do both.
What slicer are you using? Where did you get the profiles?
The brim is still very brittle even though it looks normal compared to previous prints of the same STL. It is a printable scenery STL dungeon wall tile that I have printed multiple times without issue. This occured after I changed out a filament spool so I assumed this was the problem. Additionally, when the filament extrudes it is in a very thing amount and curls upward or gets tangled at the end before dropping down to the bed after extruding a bit
Re: Extruder Problem
Time to learn how to do a COLD PULL ...
With filament already in ...
Let the printer cool down (extruder temp should be less than 40c).
Open the Bondtech Gear door.
Set the nozzle temp to 85c ...
-- keep a steady upwards tension on the filament until it releases from the nozzle.
Trim the filament; reload normally.
Sometimes more than one cold pull is needed to clean the nozzle. Also, sometimes filament fragments fall down the PFTE tube and jam inside the heat break. Only a thorough air out of the extruder will help this. A can of air, and after a cold pull stick the air nozzle into and around the PTFE and blow for a bit. Sometimes you'll need to pull the nozzle do clean dust from the PTFE. Carefully follow the manual to do a nozzle removal. Heating is required - and you must loosen and tighten the nozzle at temp.
Is there a video or step by step instructions on how to do the PFTE tube cleaning? I thought a cold pull was only needed when the filament was stuck and you can't unload through the LCD screen. I am able to unload the filament although it usually has a very fine Stringy bit attached when I pull it out.
Re: Extruder Problem
You mention a thin powder near the hobbed bolt drive. Are the teeth partly blocked? This happens when the temperature in the hot end is too low and the filament is not melting. The drive turns and chews the stuck filament. Clean with a toothpick or similar.
To reduce the chances of it happening again, raise your printing temperatures for that filament by 5 to 10 degrees in the slic3r profile and re-slice your model(s).
It did look like the "powder" was caking the teeth and I cleaned it out. I use the slic3r Prusa program using PLA. I only print with PLA. Is that still something I should be doing? Won't that cause the first layers to be "Squished" down and effect print quality?
Re: Extruder Problem
Yes it is still something to do, even with just PLA.
Not all PLA extrudes at exactly the same temperature. The best temperature for each Manufacturer's roll depends on additives and colouring agents as much as base material and age. It is actually recommended to print calibrations including a temperature tower for the first roll of each Manufacturer and each colour from that Manufacturer and if necessary make a new Filament AND a new Print profile for that combination in Slic3r.
Far from causing a problem, finding and applying the best printing temperatures and speeds is the key to improving print quality.
Bill
Tagaytay City, Philippines
Founder member of Philippines Prusa Printer Owners FB Group
Sponsor Pillars of God Academy in Bacoor
Re: Extruder Problem
Every once in a while you'll need to do a cold pull mid roll of perfectly good PLA or other filament. Whether it's a foreign particle of something left from a higher temp filament, cold pulls are something you need to learn. It is very simple after you've done it once.
The powder on the teeth is filament dust. Usually the cause is a partial or complete plug and the motor keeps grinding even though the filament isn't moving. First thing is to open the door and clean out the dust. Then do a cold pull. That should bring up whatever is plugging the nozzle. Then you can use canned air to blow dust out of the PTFE tube. This is usually enough: just stick the red straw into the PTFE and blow. Any fragments will usually come up. Once you've blown the dust from the gear area and filament sensor, close the door and reset tension on the two screws (spin screws in until the just touch the springs, then add a couple turns. The ends of the screws should not extend above the door surface.
Then trim off a couple inches of the old filament to remove the damaged segment, and reload normally.