PLA keeps breaking at the PTFE tube
PLA keeps breaking at the top of the PTFE tube after the extruder gear. This is the 3rd time it's happened and I'm using a pretty good quality PLA too. I've not had this problem with TPU or PETG.
This time I'm really stymied. I've tried to clear the blockage and have had no luck. I'm worried I might have damaged the PTFE tube and may have to disassemble the entire extruder.
I've tried pushing a needle down through the filament hole past the extruder gear and into the PTFE tube but I can't get the needle to even enter the tube. I'm hoping someone has a neat trick for me that will save me some hassle of disassembly.
RE: PLA keeps breaking at the PTFE tube
Hi Lisa,
If you remove the bondtech idler tension screw and flip the idler door out of the way. you should be able to heat the extruder (Hotter than normal) to make life easier. and push the end of the filament down into the extruder with a 1.5mm allen key fed in through the filament entry hole. once the filament is moving, you should be able to restore the tension screw, and feed new filament into the extruder gear.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: PLA keeps breaking at the PTFE tube
Is this happening when you try to unload or while printing?
If it's just happening randomly your PLA may have absorbed too much moisture and has become brittle. Take some off the spool and bend it by hand and see if it breaks easily.
The MK3 we have at work sometimes has issues unloading PLA because there would be an "elephant foot" at the bottom, found I would often have to extrude some first to get the end into the hot zone and then unload it fast. Haven't had a problem with my MK3S at home.
RE: PLA keeps breaking at the PTFE tube
@joantabb
Thank you for the tip about heating the PLA hotter than normal and for the specific allen key fit. I've still had no luck though. 🙁
RE: PLA keeps breaking at the PTFE tube
@mrschultz02
This issue is happening in the middle of a print. The PLA I'm using still has flex in it and doesn't appear to be brittle but it seems that it is not strong enough to stand up to the extrusion process of the MK3. It works great on my Tinkerine Ditto Pro. I'm thinking I won't be able to use this filament anymore with the Prusa. I have had great prints and no issues with PrusamentPLA, PETG, and TPU.
RE: PLA keeps breaking at the PTFE tube
I am dealing with a similar issue. The gears grind the filament until it is too weak and snaps. In my case, it is certainly related to friction/jam in the hotend. My PTFE tube was deformed, and thus not completely smooth inside. I haven't found what my second problem is just yet.
Are you able to print with your other material currently? That is, after you first experienced this, have you tried your PrusamentPLA successfully? If other materials are unsuccessful, I would bet on a clogged hotend.