Solved Bad day - clogged Hexagon hot end

Today is just not my day. After finding a bent Z screw and chips on my heated bed, I have now managed to clog my hot end up with ABS. I was printing overnight and the print failed due to lack of proper support. When I restarted the print, nothing was coming out of the nozzle and upon further inspection, I found that the hobbed bolt ate away at the filament. I heated the extruder up to 235 and then tried to GENTLY work the filament that was sticking out below the bolt, but it ended up finally breaking off.

Per previous instructions from Robo support, I removed the hot end using the quick release and set the Hexagon upside down in a loose vise. I then heated the hot end up again to 235 and watched for ABS to run out of the hot end. So much for that. I just ran to my local music store and bought a pack of guitar strings to now try to heat up the hot end and stick the guitar string through, but the string won't get into the hole. It is definitely heating up, so not sure what is up with that.

So I read something about soaking the hot end in acetone, but I noted a red flexible material at the top of the hot end and didn't feel comfortable with this process without asking you guys what this is. Here is a photo of my clogged hot end:



So, any suggestions? Do I give it the acetone dunk overnight and pray this clears the ABS? Or does this red material mean something significant and I should find another method? I really don't want to buy another hot end.

 

OK, I will give that a try - thanks!

 

You also may be able to remove the brass inert at the top of the hot end (the brass thing around the filament in your picture)

You should be able to unscrew that with a flat head, then get some needle nose pliers to grip the filament inside and pull out after heated to temp. If you don't have a fan cooling the heatsink don't wait too long after it reaches temp because that will keep getting hotter

 

OK, it took quite a while, but I was finally able to get the filament out! The heat block loosened up, so I took advantage and removed it. Heated up the small allen wrench that comes in the tool kit and kept shoving it in until it popped out. Nozzle is soaking in acetone overnight and then I will put this all back together (hopefully correctly). Then I get to do a Skype session with Robo to replace my right Z screw. And why did I decide to get into this hobby? LOL

Thanks Mark and Mike! You guys truly are the best!

 

I had the same problem today (must be that time of the year). Found the simplest solution was to separate the hot end from the heat dissipater (use the supplied mini wrench to unscrew the two. Remove the thermistor, heater element, and rubber cover from the hot end. Then submerge both metal parts in Jasco Paint and Epoxy remover for about 15 to 30 minutes. Then use a small item that just fits the hole in the heat dissipater to push out the offending clog and a strand from a copper wire to push out any offending material in the hot end. Then rinse with water, re-assemble the parts, re-season the extruder, and you are good to go. The whole process took me 1/2 hour and was totally successful.