Clogged nozzle

[usarmyaircav]

Somehow I clogged the nozzle of my Hexagon 1.75mm. What is the best way to get it cleaned out. I had finally gotten my printer to work thanks to prinbus helping me with a pebkac issue. I had 3/4 printed the test cube, and all of a sudden the printer was still moving but no filament was coming out.

Todd

[AbuMaia]

If you're using ABS, drop the Hexagon into some acetone. Or, for any plastic, heat up your Hexagon and feed a length of guitar string up through the nozzle to clear it out.

[printbus]

Have you already tried to remove the filament from the extruder, cut off the end and re-feed it? There's a lot of things that can cause the filament to stop extruding, with the nozzle not being clogged. Examples -

• Bulges in the filament that get caught at the top of the hot end (my *favorite*; dark filaments are prone to do this)
• Excessive spring pressure on the guidler causing deep cuts in the filament that causes it to catch on the hot end (I haven't seen this, but I've read about it and it makes sense, but I don't recall anyone proving spring pressure was a direct cause of extrusion problems)
• The filament spool not rotating freely enough (multiple people have seen this happen with the stock spool mount)
• Overzealous retraction leading to the hobbed bolt rotating back and forth over the same length of filament, carving away at it
• Too low of a nozzle temperature (leading to the hobbed bolt having to apply a lot of pressure to force the extrusion)
• Too fast of a print speed (hot end can't keep up with the flow volume)
• hobbed bolt teeth contaminated with filament shavings or other material
• filament shavings falling onto the top of the hot end where they migrate into the feed tube of the hot end, increasing resistance to filament movement (makes sense, but also unproven)
• combinations of the above
• filament actually only fed down to the top of the hot end, and not actually into the tube of the hot end (1.75mm filament in the 3mm-capable wades base is real prone to this)
• trying to use a soft or flexible filament in the wades extruder that has a large gap between hobbed bolt and top of the hot end

EDIT: I've probably had the extrusion stop over a hundred times, and only once or twice has it been due to an issue with the nozzle. Of course, I do pass the filament through a felt pad at the top of the extruder to wipe off the plethora of cat and dog fur in my work area. (see the white spot above the extruder in my avatar - that's the felt disk) That could be wiping off dust and who knows what else from the filament that could end up forming a clog.

[usarmyaircav]

Thanks, I am using ABS, I am on my way out so will pickup some acetone. I am sure I have old guitar strings too so will look for one of those. Thank you!!!!

[usarmyaircav]

I took the hexagon all apart and can feel filament down to the nozzle, so took the tip off and can see there was filament coming out of the tip, like it broke off and got stuck. When I tried to print again, it didn't do a thing, not even any ooze.

[AbuMaia]

Bulges in the filament that get caught at the top of the hot end (my *favorite*; dark filaments are prone to do this)

I've had this happen at the tail end of a spool of MakerFarm clear ABS. It's got bulges about every meter or so. I don't know how many prints were ruined before I found them and tried sanding them down. Even still I miss some and ruin a print. Glad this spool is almost finished.

[usarmyaircav]

Here is what the nozzle looks like.

[printbus]

The picture's pretty blurry, and we don't know what color ABS you were printing. Perhaps someone will argue otherwise, but I wouldn't jump to conclusions by seeing the nozzle "plugged" after you've pulled the filament out of the extruder and then removed the nozzle. I think finding filament remaining in the nozzle is pretty typical - it has been for me. I still think that the only way you can really say it is clogged is if you've tried to re-feed the filament through at least one more time if not a couple of times. If it still doesn't work, then it's time to try pushing into the hot nozzle with fine wire or soaking the nozzle in acetone overnight if it was printing ABS.

[Schnupp]

Im also currently having the no extrusion issue however mine is probably due to the fact that ive been experimenting with a new hot end (Prometheus). My filament looks like its being chewed up pretty good no matter the spring pressure. Im going to play with the temperature and see if that makes a difference. Im currently at 230 for ABS 1.75 filament

[printbus]

I've had this happen at the tail end of a spool of MakerFarm clear ABS. It's got bulges about every meter or so. I don't know how many prints were ruined before I found them and tried sanding them down. Even still I miss some and ruin a print. Glad this spool is almost finished.

It's interesting that you see that on clear, and on your E3Dv6 hot end no less. The argument I hear about is the bulges are the heavy amount of dye used on dark filaments coagulating on the outside of the extruder forming the filament, especially if they are made from remixing other filament scraps and enough dye has to be added to overcome the underlying colors. So far I know I have had two spools with bulges (one TonerPlastics black PLA from MicroCenter and a new MakerFarm blue PLA) and one that I suspected before returning (TonerPlastics clear PLA).

I've been seriously considering moving to the E3D, in part because as I understand it, the E3D has a wider feed hole than the hex and is slightly more tolerant of the bulges.

If you follow my build thread, you may have noticed that I've separated my filament spool from the printer. A main reason why I did this is because I envision feeding the filament through a tipping plate mechanism that trips an alarm if a bulge won't pass through it. I figure that may give me some time to remove some of the bulge with a dremel tool or something if I'm in the area, and somehow terminate the print if I'm not.

I can't over-emphasize to new people that IMO, a truly clogged nozzle is probably the last reason why extrusion stops on you. It's also the hardest reason to verify, so eliminate all the easy possibilities first.