What would make a 3D printer suddenly start clogging repeatedly? (CR-10)

[J.Emmett Turner]

What would make a 3D printer suddenly start clogging repeatedly? (CR-10)

My brother and I recently got a CR-10 and went through two full rolls of filament and the original small roll without any clogging or filament issues. Suddenly, it's clogging every other print. We are using cheap Inland PLA but the first half of the roll worked great. We were running it a few degrees over the high end of the recommend temperature range, as suggested by other CR-10 users who had trouble without doing this.

When it first started we were hearing a "click" sound as the gear feeding the filament would slip/skip. Sure enough, the extruder nozzle was badly clogged. The "Atomic" method for clearing it did not work. We cleared the clog but it happened again in the first layer or two. We cleared it again, thoroughly disassembling the extruder and trying again with a higher temperature but it clogged almost immediately again. The next time we cleared it spotlessly and replaced the original cotton + kapton insulation pieces with equivalents from Amazon. We upped the temps about 5 more degrees and it printed several more items without issue before it inexplicably clogged again. ARGH!

It's almost like the first half of the spool was good filament and the second half is contaminated/bad somehow. Is that known to happen? Could it be related to humidity? The outdoor temps have changed a lot since our trouble-free days but temperature indoors is controlled. Humidity, on the other hand, has fluctuated. If anything it should be LOWER but if the filament absorbs it over time perhaps that doesn't matter? Should I build a dry box or is that only for specialty humidity-sensitive filaments? Should I generally remove and store it between prints?

We've been out of commission for almost 2 weeks now so any advice is appreciated!

 

[FryingSaucer]

Have you only used the one make of filament? If so why not try a different one. If it's still clogging it's likely not to be the filament. I use Real Filament and have never had any problems.

 

[Redbrickman]

I'm still awaiting the arrival of my first 3D printer so just a beginner, but I would check the diameter of the filament in case part of the roll is not dimensionally accurate. People have had problems with cheap rolls where the filament diameter has been way off in places.

 

[J.Emmett Turner]

Have you only used the one make of filament? If so why not try a different one. If it's still clogging it's likely not to be the filament. I use Real Filament and have never had any problems.

It's the only make I've used other than the small sample spool it included but I have successfully used a spool and a half of the current stuff without issue before my problems suddenly started mid-spool.

I'm still awaiting the arrival of my first 3D printer so just a beginner, but I would check the diameter of the filament in case part of the roll is not dimensionally accurate. People have had problems with cheap rolls where the filament diameter has been way off in places.

I'll break out the digital calipers and check that. Thanks!

 

[The Hat]

@J.Emmett Turner, I’d guess that the PTFE lining in the throat has been damaged or twisted and the filament is jamming on, the click click you hear is the extruder not been able to feed any more filament into the head, maybe you were running the nozzle to hot.

You’ll need to completely dissemble the hot-end and use something very small to push through to clear it from any old filament, best to do this when hot, a quicker method would be to install a new throat...

 

[Nifty]

I heard recently that there can sometimes be gaps between the PTFE tube and the hot-end. Over time melted plastic gets stuck in there and causes problems.

I've also heard that the PTFE tube isn't going to last forever and sometimes they even break down into the hot-end and can gum things up.

Of course, it could be a ton of other things, like bad filament, some other obstruction, etc.

Good luck, and please keep us posted with what you try!

 

[guymark]

PLA (and to a much lesser degree ABS) do absorb moisture and if the spool has been open for a while and especially if the humidity has increased this to me seems the most probable cause for the failure. Much more likely than the spool being half good and half bad. Not impossible of course, but I think very much less likely.

If you have another spool of PLA which is unopened, it might be worth loading that moments before you want to do a print - and then putting it back inside an airtight jar (along with a few sachets of silica gel). I am guessing "dry" filament might sort the problem out quite quickly - and yes, it does tend to "keep on absorbing" over time given half a chance.

Storing filament (especially PLA) in an airtight pack along with silica gel sachets really is worth doing unless you print HEAVILY and tend to get through a spool within a very short time of opening it.

As others have said, please let us know what it was when you hit on the problem - as it may be something we can all learn from

 

[J.Emmett Turner]

@J.Emmett Turner, I’d guess that the PTFE lining in the throat has been damaged or twisted and the filament is jamming on, the click click you hear is the extruder not been able to feed any more filament into the head, maybe you were running the nozzle to hot.

You’ll need to completely dissemble the hot-end and use something very small to push through to clear it from any old filament, best to do this when hot, a quicker method would be to install a new throat...

It did get damaged when trying to clear the first clog but we trimmed it back. worried that we damaged it by reinstalling improperly, we trimmed it back again and it has been perfect ever since.

I heard recently that there can sometimes be gaps between the PTFE tube and the hot-end. Over time melted plastic gets stuck in there and causes problems.

I've also heard that the PTFE tube isn't going to last forever and sometimes they even break down into the hot-end and can gum things up.

Of course, it could be a ton of other things, like bad filament, some other obstruction, etc.

Good luck, and please keep us posted with what you try!

Yes. When we cleared our first clog we didn't fully reinsert it, which caused this exact issue. We trimmed it back and ensured it was fully seated so the tube hasn't been a problem since. Clogs, unfortunately, continued. The CR-10 also includes a spare PTFE tube but we haven't needed it yet.

PLA (and to a much lesser degree ABS) do absorb moisture and if the spool has been open for a while and especially if the humidity has increased this to me seems the most probable cause for the failure. Much more likely than the spool being half good and half bad. Not impossible of course, but I think very much less likely.

If you have another spool of PLA which is unopened, it might be worth loading that moments before you want to do a print - and then putting it back inside an airtight jar (along with a few sachets of silica gel). I am guessing "dry" filament might sort the problem out quite quickly - and yes, it does tend to "keep on absorbing" over time given half a chance.

Storing filament (especially PLA) in an airtight pack along with silica gel sachets really is worth doing unless you print HEAVILY and tend to get through a spool within a very short time of opening it.

As others have said, please let us know what it was when you hit on the problem - as it may be something we can all learn from

Will do! Thanks for the info/advice. I'll definitely put it into practice. I believe I went through my first roll of this much faster and had no issues so you're probably onto something.

I completely disassembled the extruder again to completely clear out the obstruction and replaced the cotton/kapton with a fresh piece again last night. A couple hours later and about half-way through the next print I heard a few of the same clicks that I hear when it's jammed but it recovered and the print finished with no major issues. Using up the rest of this roll is going to be a nightmare so I might as well switch now and see if I get better results with a fresh "dry" roll. Thanks!

 

[The Hat]

A couple hours later and about half-way through the next print I heard a few of the same clicks that I hear when it's jammed but it recovered and the print finished with no major issues.

Try slowing down the feed rate of your extruder, try 98% to start with...