Hot End Clogged with eSun PLA

My hot end is hopelessly clogged with eSun 3mm PLA. When I tried to remove the filament it broke off at the entrance point so your online solutions won’t work. I’ve tried raising the temp and pushing it through with the pointed end of the metal rasp but it’s hopelessly stuck.This is the second time this has happened with this type of filament. The first time I luckily had an extra hot end so I replaced it. At that time, I had been having issues with filament sticking to the heated bed. When I replaced the hot end, I found that the funnel shaped piece on the larger fan was cracked and broken in several places. Since my other Mini has a flexy-struder head I was able to replace that piece. The quality of the print was very poor - something I’ve noticed with other Lulzbot 3D printed components. I can’t just reprint it because it has several screw sockets embedded in it.

In the meantime, I need to know how to remove this filament because I can’t afford to keep replacing the hot end and you’re out of them anyway. I had issues with the hot end on my first Mini and broke it trying to fix it. That’s how I ended up with the Flexy print head - it was all that was available and I have a small education business that relies on these printers! The lack of replacement parts is alarming and can put a small operator like me in real trouble.

So, we have several issues here. The most urgent is

  1. The clogged hot end. I have several student prints that I need to get out by Tuesday and will have to pay for access somewhere else to print them.

  2. I still need to replace the fan funnel piece for my now spare print head but am not sure how to proceed. I will have to buy yet another hot end for that print head, which I’m not happy about. These printers are both fairly new.

  3. The clogged head is a recurring issue and the fact that I can’t replace the hot end implies that many others are having the same problem. It’s like buying a car and the steering wheel breaks and the car maker says ,“Sorry, we’re out of replacement steering wheels.”

The machine is under warranty. How can you help me with this clogged hot end asap.
Thank you,

My advice to you is to buy a few E3D V6 nozzles in the size you currently have on the Lulzbot machine and replace the standard Hexagon nozzle with the E3D unit. The E3D nozzle is a little longer, allowing you to tighten it against the heat brake in the Hexagon the same way you would on the E3D V6. That eliminates the need for all the nozzle torquing nonsense Lulzbot recommends for the Hexagon nozzles.

Locate the proper wrenches, one for the heater block and one for the nozzle.
Heat the hot end to 160C and turn off the nozzle heater.
Use the wrenches to hold the heater block in place and remove the nozzle.
Start the new nozzle in the heater block threads. Make sure you don’t cross thread.
Reheat the hot end to 160C and turn off the nozzle heater.
Finish threading in the new nozzle until it contacts the heat brake. The flange of the new nozzle will be held away from the heater block.
Snug the nozzle up. Not too tight.
Heat the hot end to 240C, turn off the nozzle heater and retighten the nozzle. Just snug. It doesn’t need to be very tight.

On my mini, I didn’t need to make any other changes. The wipe and probe functions work fine.

Remember to turn off the hot end heater before going to work with the wrenches to avoid shorting out any electronics.

Thank you for the information. Will this work?

That is it but the price will be much less at filastruder or MatterHackers. I personally use filastruder.

If you are running a stock Taz, with 3mm filament, you will want the 3mm nozzle. The link you posted was a 1.75mm nozzle.

Have you tried removing the extruder body (plastic piece with the gears and motor) to reach the filament before the actual hotend?

Next time get some pliers or locking forceps to pull the filament out… :slight_smile:

I did use pliers. The filament broke off right at the entry point to the metal hot end so I can’t get to it. I’ve read online about someone removing the hot end and torching the filament to melt it. I’m not sure if that’s a good idea or not. I have a very small jewelry torch.

I have had that problem with esun. It is super brittle compared to other PLA I have used.

Torching never ended well for me back in the Budaschnozzle days of my Taz 2.

If things are really bad, you can disassemble the hot end and dissolve the PLA by soaking it in Scigrip 4. My bottle of Scigrip has saved over $100 worth of nozzles.

Thanks. This seems like something I’ll do a number of times as well. The brittle filament is probably why Lulzbot is discontinuing eSun PLA but instead of just discontinuing it, they sold their inventory at a steep discount on Black Friday. Sounds like everyone just got a clogged hot end at a really great price. I’ll try the solvent. Thank you again for the help.

One thing to remember about PLA is that it does not like to sit in the nozzle at printing temps for long periods of time. It will crystallize and possibly char if the temps are high enough. Make sure you are cooling the nozzle when prints end and are not warming it to print temps too long before the print begins.

As much as I can bash esun for being brittle, I have had really good print quality from it without any real clogging issues.

Thanks, this is good information. I try to follow those guidelines and believe that the previous print had finished and cooled. This happened during a print that had multiple separate pieces. It started printing as usual, then stopped extruding.

I clean out the hot end regularly with a cleaning filament to pickup any debris so I’m not sure what more I can do other than learn how to clean the thing out. I guess I should only print one piece at a time with PLA. Have you ever multiple pieces to be an issue with PLA? Thank you again for your responses. They’ve been helpful.

If this is a mini with the small squirrel cage hot end fan, I wonder if you actually having some heat creep related filament swelling causing a jam in the cold section of the hot end rather than a nozzle clog. A filament stoppage due to heat creep can cause a clog in the nozzle if the print is allowed to finish without any filament being extruded. The PLA crystallizes.

You could try directing a small fan at the printer during a print that would normally fail and see if that helps. Those squirrel cage fans are barely adequate for PLA when they are running at 100% but they have a nasty habit of partially failing and causing problems with PLA prints. They will still spin but not enough to prevent heat creep.

If you are printing thin layers or thin walled parts that have low filament flow, the problem is worse due to the low amount of filament movement through the hot end. In that case, printing the thickest layer you can might help a little.

I’m with nopick on this one… a new hotend is probably the easiest solution.

If you want to try and salvage the existing hexagon, it can be disassembled. Try removing the heat block by reversing the assembly found here. If you’re lucky, removing the heat block should pull the filament out out of the heatsink. At that point, put the heat block in a vise, heat the nozzle with a torch and simultaneously pull on the filament.

Good luck!

Another thing you can do if you still have some filament to grab is remove the cooling fan from the hotend and set the hotend to printing temperature. While it is warming up, pull on the filament. It will usually soften enough to stretch and come out. That’s the last resort before disassembly for me.