From bad to worse - troubleshooting extruder loading
Up until a couple of months ago, the Mini was my most reliable printer (in some cases more than my MKS3+). Then after one print, it refused to load filament. I played with it for a little while, resolved to come back to it and then couldn't find the time until today. Previously I checked the tightness of the extruder screw, checked for filament lodged in the chamber and watched the gears. I repeated these steps today, but wasn't able to get it to pull filament into the extruder.
I opened the extruder, made sure there were no clogs, used a can of air to clean it and proded the gears to make sure nothing was there. I then retightened the idler and tried again. This time, the extruder pulled filament in and then popped open the flip lid over the gear and started feeding material into the air. I stopped this and it pulled the filament back through. I again checked for a clog or filament shavings, but didn't find any. Multiple attempts got the same result, though when I made the idler too tight it wouldn't feed or would actually making a grinding/screaming noise when the filament would load. On the last attempt, the filament feed in on itself before I could catch it and then back into the gear. I cleared it, but some of it appeared to stay trapped in the channel. I went to release the idler to clear it, but now the idler screw just turns but never loosens. Does anyone have any suggestions what I can do here? I can't even get the idler to release so I can clear the trapped filament.
It's super frustrating. I don't understand why it stopped working properly and now I can't even do the maintenance steps to address it. 🙁
RE: From bad to worse - troubleshooting extruder loading
I have not taken the extruder apart, but have you checked for a clogged hot end or bad hot end PTFE tube? That seems to be a wear item and when it goes bad, it is difficult to push filament into the hot end, backing up into the extruder.
If you take off the Bowden tube and push filament into the hot end by hand such as doing a cold pull, you can feel the difference.
Regards,
Mark
RE: From bad to worse - troubleshooting extruder loading
WizarDru
When my Mini makes the clicking noise and screeching noise it is a clog that i found in the extruder. on my Mini extruder there is a small piece of ptfe tube under the brass fitting on the discharge side of the extruder, i thought it was the hot end at first because there was still filament in all of the bowden tubes. but taking it apart and pushing filament through the hot end worked so i went back to the extruder. take out the brass fitting on the discharge port of the extruder an look at this short ptfe tube i have had this plug up a few times when i use cheap PLA. you should be able to get the remainder of the filament out of the extruder using the steps in the users manual. I hope this helps, may not be the case but it won't hurt to look into it.
"WizarDru
I again checked for a clog or filament shavings, but didn't find any. Multiple attempts got the same result, though when I made the idler too tight it wouldn't feed or would actually making a grinding/screaming noise when the filament would load."
Master of Wood DisasterCharter member of the woodturners funnel club
RE: From bad to worse - troubleshooting extruder loading
Thanks, I'll give that a shot. I'm hoping to avoid removing the extruder and taking it apart. I'm not sure why it's having this problem, but I have to assume something is jammed in there. The problem is definitely not a clog on the hot end. I'm just hoping I haven't stripped the screw or something. I'll work on it more again tomorrow.
RE: From bad to worse - troubleshooting extruder loading
So, the primary issue I need to resolve now is the idler screw. Before I can figure out why the extruder isn't feeding into the PTFE that leads to the hot-end, I need to be able to remove the screw (the one with the spring) that secures the idler. The screw head is NOT stripped. I can put an allen wrench into it and it turns (and I can feel the screw turning on the other side). The issue is that the screw doesn't appear to be moving when I do so. It turns forever, never loosening.
Does anyone have any suggestions how I can extract the screw?
In terms of what's happening with the extruder itself, it will feed the filament, but it ends up coming out of the top of the extruder. I assume this is because it's so tight now that it cannot feed into the PTFE tube and has to go somewhere. It was experimenting with the idler tension that lead to me (I assume) over-tightening the screw. But now I can't adjust or remove it. This has made the printer completely non-functional.
RE: From bad to worse - troubleshooting extruder loading
Oh, and this is the issue I’m trying to resolve once I figure out the screw: