Filament Simply Not Working

[Zulfe]

My extruder will not, under any circumstances, extrude filament. I've tried adjusting to different tensions, spun the spool to give it more available filament, and waited to make sure everything at the bottom of the hot end is gooey. Nothing.

I, if you've seen my earlier post you'd already know this, tried some filament I purchased from MakerGeeks (cheap Chinese bullshit that, in my opinion, makes MakerGeeks look cheap) and had a ton of issues with it clogging up my hot end. In my numerous test extrudes, I've cleaned out all the green filament that was previously being run in there, so now it's all white.

When I try to extruder, I get about 5mm, then the filament makes a clicking noise, and twitches from the top of the extruder to the spool. When I open it up, the filament is heavily chewed and has no possibility of moving. Nothing I seem to do fixes this. I'm using MakerFarm filament, and the spool is 5/6 used up, as I've used it before. When I set it up the first time, it was easy. I had the tension right as soon as I loaded it in. Now, no matter what I do, I can't fix it.

I'm extremely frustrated, so if anyone can help, that'd be awesome.

[clough42]

You didn't say whether you're using PLA or ABS.

I had a similar problem early on with my Hexagon 3mm/.4mm hot end. It would extrude a bit, then clog and strip the filament. I think I had a particle of something down in the melt chamber that kept blocking the outlet. When I pulled the filament back, it moved and I could extrude a little more before it moved back down and clogged the opening.

I disassembled the hot end and soaked it in acetone to clean it out. I repeatedly soaked it to soften the ABS, picked what I could out with tweezers and soaked it again. I pushed a small guitar string into the nozzle from the output side and cleared out the hole. Once I had all the plastic out, I wiped out the inside with paper towels, tweezers and more acetone until it was spotless.

After that, I reassembled it and it's worked flawlessly. I've run several kilograms of MakerFarm ABS through it since.

Acetone won't work on PLA, though.

[Mjolinor]

Reading through the posts on here one of the members reported having to replace a nozzle even though it was thoroughly cleaned out it would still jam. This I took with a pinch of salt believing that he must not have cleaned it out right. I can now confirm this is the case, I have just replaced both my nozzles because they would not stop jamming and I know they were clean.

The only reason I can see for this is that the inside of the nozzle gets scratched and caused the filament to be harder to push out or the thermal conductivity of the nozzle changes with time.

Either road up the conclusion is that the nozzles do go knackered even though they seem to be OK to look at.

[gmay3]

Zulfe,

Here's something to try for a sanity check to make sure the nozzle isn't clogged. Get your hotend up to full temp and then loosen the tension of your extruder's bearing guide and manually push the filament down with your hand into the hotend. You should easily be able to extrude this way.

If your able to manually extrude filament then it means there's something wrong with your extruder assembly and your hot end is probably fine. I would take apart/clean out your extruder and see if there are any mechanical flaws preventing extrusion. Check the bearings and check the mechanical integrity of your printed parts.

[Zulfe]

Thanks for the replies, everyone.

I finally fixed it by taking the hot end off the extruder block, holding it with a pair of pliers, heating it up to ABS printing temp, and using an allen key to push a chipped part of filament through the nozzle. When there was nothing coming out, I cooled it and shook it. A small, green and black beady thing fell out, then it worked fine. Chinese filament, eh?

[gmay3]

Man that is textbook! I've seen a picture of the beady thing your talking about before on the reprap wiki. I don't know where all these beads are coming from but I guess it's good luck to break a necklace or two above the filament hopper at the ol' filament factory.