Clogged Hot End?

[JeremyAgost]

So my cat attacked my printer today and I came home to find the nozzle buried in a blob of ABS. Now it seems to not be printing correctly anymore. When I bring it up to 230ºC and run the extruder manually it barely extrudes anything. I can feel the filament going thru extremely slowly, it's definitely blocked up somehow. I tried increasing the temp to 250º and extruding more but it didn't seem to help. Anyone have any suggestions for clearing it out? I was thinking maybe a drill bit, if I can find a small enough diameter.

[bubbasnow]

im asuming you have a stock nozzle?

take it out in the shop, hit it with a flame and pick the plastic out with a paper clip until you can see inside and its clean. stick the pfte tubes back in the nozzle and shove it back in there after it cools you should be ready to go.

[JeremyAgost]

Thanks! That sounds like it just might work. I ordered myself an E3D v5 hot end, just gotta get this thing back in service in the meantime. Especially since I planned on printing some adapter parts

[lordbinky]

For ABS you can let the nozzle soak in some acetone and then use a small wire ( I use a single strand from a piece of stranded wire) to clear the gunk. PLA is more of a pain since you can't dissolve it like that.

[Batteau62]

For ABS you can let the nozzle soak in some acetone and then use a small wire ( I use a single strand from a piece of stranded wire) to clear the gunk. PLA is more of a pain since you can't dissolve it like that.

I agree with lordbinky, soak it in acetone, I use the first E string of a guitar it's .o12" spec just happens to fit nicely into a .5mm nozzle. They are extremely stiff(but can be bent) which helps in poking at blockages between cuss words and when you get it unblocked, you just re-string, tune and play a happy little printing ditty

[MSURunner]

For the PLA jams I got when I was using the stock hotend, I removed the liners, placed them on the build platform and heated it up to like 70* and ran a paperclip through the liner after the PLA had softened. Might help you if the clog is somewhere in the PFTE barrel liners...

[Nylocke]

To clean out the nozzle when it jammed from PLA, I took a butane soldering iron and removed the tip so it was a jet of flame and burned the PLA out. That should also work nicely with a blowtorch, Bunsen burner, etc. just be careful not to burn yourself.

[626Pilot]

To clean out the nozzle when it jammed from PLA, I took a butane soldering iron and removed the tip so it was a jet of flame and burned the PLA out. That should also work nicely with a blowtorch, Bunsen burner, etc. just be careful not to burn yourself.

I use the biggest "sealed burner" on my stove. If I take off the metal disc on top of the burner after it's lit, it gives me a good 16" jet of blue flame. I bet a lot of people have stoves like that. Requires some caution and risk tolerance though

[Mechman]

I've just finally fitted my PEEK fan and first run up the PLA has frozen inside.. even at 220 deg i cant get it to budge... so I need to take it apart and take a flame to it?

I cant believe there's not a better way....

[MSURunner]

Where is the jam located? If it's in the nozzle, then I would suggest heating it to 250/260 for about 5 minutes to "liquefy" the PLA and you should be able to extrude again. If it's in the barrel liners, more likely, then, yes you need to pull them out and clear the jam. I find it very rare that you should have to a torch to a nozzle to clear a PLA jam, usually just a heat soak is enough to clear PLA unless there's a contaminant in there.

[Mechman]

Where is the jam located? If it's in the nozzle, then I would suggest heating it to 250/260 for about 5 minutes to "liquefy" the PLA and you should be able to extrude again. If it's in the barrel liners, more likely, then, yes you need to pull them out and clear the jam. I find it very rare that you should have to a torch to a nozzle to clear a PLA jam, usually just a heat soak is enough to clear PLA unless there's a contaminant in there.

Am still very green around the gills with these machines. I didnt build this one, so I am still finding my way around. I have no idea where the blockage is, how would I tell the difference? I am concerned about damaging the thermisters stuck on the side of the hot end.

appreciate your help here mate

[626Pilot]

If your hot end jams, disconnect the Bowden tube from it. You will find a swelling at the end of the filament. That's what causes the jam. Cut it off and reinstall.

Also, don't set your hot end to 250 degrees to liquefy the PLA unless you are using an all-metal hot end. The PEEK will soften and begin to melt even with the cooling fan on.

[Mechman]

If your hot end jams, disconnect the Bowden tube from it. You will find a swelling at the end of the filament. That's what causes the jam. Cut it off and reinstall.

Also, don't set your hot end to 250 degrees to liquefy the PLA unless you are using an all-metal hot end. The PEEK will soften and begin to melt even with the cooling fan on.

Yikes, now ya say lol.
It was definitely in the nozzle, the heak soak at 260 worked a treat. Guess I was lucky this time.

thanks guys

[Mechman]

ok at the risk of hijacking this thread, I have fitted a 25mm PEEK fan and now i am struggling to get any PLA out of the nozzle. Even with the temp set to 220 its not extruding at all. I assumed I would have to alter the material setting for temp once this was fitted, but what am I doing wrong?
The fan seems to be working independently of Repetire as in, the fan control on the manual page does nothing (am assuming that is for the part cooling fan?). I have the fan plugged in to HEAT 1?

confused....

[626Pilot]

The cooling fan is plugged into the port right next to the hot end heat. If Repetier isn't turning it on and off when you press the Fan button you may need to hit the reset button. I've noticed that Repetier sometimes gets buggy when I have it extrude filament - it will stop responding to commands after that, and the only fix is to reset the RAMBo.

Your cooling fan should be installed with the printable shroud. After that, my recommendation would be to heat the hot end to 170. After it gets up to temp, set the temp to 220 and begin immediately feeding PLA through by hand. As you feed it through and the temperature climbs, you should notice the resistance dropping. Maybe it will flow easiest at 180, or 205, or somewhere else. As soon as it starts getting more resistant, you know the current temp is just a little too hot and you need to select a slightly lower one. Try different temps around that point, five degrees apart, until you find the right one.

[Mechman]

Ah ok, have swapped the plug to the correct one and now, after restarting Repetier it dose indeed control this fan Progress lol
I have done as you suggested and it seems that i have to run the fan at 50% or the temp needs to be around the 230 mark to get anything repeatable from the nozzle, does this sound right? Not seen it posted that the fan isnt going at full tilt. Temp seems to have settled at 195.
Am printing the 40 x 40 hollow box for a test now.

thanks again for your help. Would be lost without this forum! lol

[626Pilot]

I usually run the fan at 100%.

[Mechman]

I wonder what your ambient temp is where you are? its about 12 C in my offce at the moment. wonder if that's making a difference perhaps?

[MSURunner]

If your hot end jams, disconnect the Bowden tube from it. You will find a swelling at the end of the filament. That's what causes the jam. Cut it off and reinstall.

Also, don't set your hot end to 250 degrees to liquefy the PLA unless you are using an all-metal hot end. The PEEK will soften and begin to melt even with the cooling fan on.

Really? I've NEVER had a problem with PEEK until I had a heater run away that took the temp to burning PEEK. In fact, Ultimaker recommends a 260 heat soak as the first step for clearing a jam. I've left the Ultimaker on without a cooling fan for several hours at 240 on accident and never had a problem. I can't imagine anyone having PEEK soften at 260 when it's melting point is over 340. Not a worry of mine or Ultimaker's at 260...

[Lochemage]

So, you hadn't really mentioned this at all, and no replies seem to be mentioning it either, but... Are you sure your problem isn't that the cold end drive gear just dug a big groove in your filament? have you actually pulled the filament out of the extruder completely and inspected the filament yet? If your extruder jams or clogs enough, the drive gear will end up acting like sandpaper and will just sand a large groove into the filament where the drive gear teeth are supposed to grip; Without any grip, you have no extrusion power.