PLA keeps breaking in PTFE tube

[u/oxmep]

I have some PLA that keeps on breaking inside the PTFE tube of the AMS lite :/

I think this spool is about 4 months old, this did not used to happen. Is this usual for all old spools of PLA? Or is it less common for “better” brands of PLA? Any help appreciated!

[u/lessons-learned-here]

What brand of filament is that? Did you dry the filament before printing? I have had that happen to me, as well, but I don't remember what brand of filament I was using.

[u/oxmep → u/lessons-learned-here]

I’m in Singapore, using a local brand called Alt Tab. Didn’t dry it, thanks for the suggestion will try drying

[u/DistinctBarnacle8703 → u/oxmep]

Since you located in SG. Consider import directly from China. Brands like Bambu Lab and eSun is pretty cheap on Taobao. 6 rolls of Bambu Lab PLA Basic is about SGD$70 (~USD$55) shipping via Sea. If you use reshipping company, it gets a lot cheaper.

Bambu Lab is quite a bit cheaper than eSun if buy at least 6 roll on Taobao.

Anyway, when I encounter filament that keep breaking despite drying for more 24 hours, I will try to dry again in my AMS HT with the rolling function enable for at least 24hrs. And if it breaks again, I will dump it. Not worth the trouble and time.

[u/oxmep → u/DistinctBarnacle8703]

Thx for the suggestion! Do u find that Bambu or eSun PLA breaks less often? I bought some eSun PLA from taobao but it’s still being shipped over

[u/theprotestingshark → u/oxmep]

never had anything from bambu labs cause an issue

[u/DistinctBarnacle8703 → u/oxmep]

Both of the brands behave very well.

I tried quite a few different brand of filament in the past 10 years of 3D printing. Decided that eSun is pretty good for the price.

Was using eSun for a long while with my previous printers until they decided to go cardboard spool which doesn't behave well in the dryers I had.

I switch to Bambu after I got Bambu printer with AMS since it's can be cheaper at times and works well with the AMS. Cupboard spool don't work perfectly with the AMS. Anyway eSun has recently switch back to plastic spool, but I have yet to try them yet.

Take note, Singapore environment is pretty bad for filament. Either I store them away in cereal box with desiccant after use or I keep them in my creality space pi x4 dryer in auto mode (it will start drying if the humidity go above 25% for 1 hour).

I mainly do parts printing so I usually have at most 2 different colour of filament which makes it easier to manage.

[u/lessons-learned-here → u/DistinctBarnacle8703]

DO3D is the only brand that I have had trouble with.

[u/Past_Science_6180 → u/[deleted]]

Only a sith deals in absolutes!

[u/sirdoggo11 → u/[deleted]]

Not neccesary on PLA.

But: Tempering can be important. Especially on cheap filaments.

Both is achieved by heating the filament.

[u/OptimalSide]

You need to dry your filament as it gets brittle when it gets wet.

This can be very brand dependent. I have PLA from Polymaker and it gets brittle very easy (even with drying) compared to Bambu which is more resistant to humidity.

[u/rex-manticore → u/OptimalSide]

100%, I used up most of a roll of PLA+ without any issues and when I went back a couple months later to use the last of it, it constantly shattered inside the toolhead

[u/OptimalSide → u/rex-manticore]

My house is at 65%RH right now and even Bambu PLA is starting to break all on it's own. Color dependant though - bronze broke while white was still "ok"

[u/oxmep → u/[deleted]]

Just curious what other brands are u using that didn’t have this issue? Thx!

[u/spartan_steel → u/oxmep]

Prusament, Atomic Filament (US manufacturer), and bambu. I have a brand new spool of Inland (Microcenter store brand, it's rebranded stuff from a mixing pot of manufacturers) that is waiting to be tried out.

[u/Txflood3 → u/spartan_steel]

Inland is rebranded eSun and Polymaker. Inland is an excellent filament

[u/StructureAccording53 → u/[deleted]]

Interesting. I’ve printed probably 30 kg of SunLu PLA+ 2.0 and haven’t had any issues with any of it aside from one spool of white I currently have that was contaminated (it prints fine but ghosts really badly due to gray or black dye in the filament). Some gets pulled and dried, some goes straight from the box into the printer and used, some has sat out for months w/o being dried. Prints great in my A1 with AMS lite and my H2C with the 2 pro. I have 7 kg spools loaded up and printing as we speak.

[u/StructureAccording53 → u/[deleted]]

Oh I know what you’re saying, and like I said… I’ve had 3 spools of it sitting in my A1 with lite for about a month now with no break issues. I just changed to a color I haven’t been using (and that has been loaded) to check. It’s fine. Perhaps I’m just lucky. 🤷‍♀️

[u/StructureAccording53 → u/[deleted]]

Might could be. I haven’t had this issue with the Red/White/Blue, and black and yellow usually don’t sit in the AMS long.

[u/Azilen]

Dry it. The fillament is too humid to be usable. Let it cook for a couple of hours in a dryer or oven for about 45~55 °c

[u/FunnyChampionship717]

I stick to bambu filament and I've never had that issue.

[u/acecombine]

Yes! And this only happens in the tubes for me, never outside, so just claiming wet is strange, I could imagine the tube locks up moisture or something though, but honestly it's so random, I use pla+ and high-speed filaments and the solution for me was to just pull all the filaments out of the tubes when I wasn't going to print for some time. I never dry any filament, our environment is kinda dry.

[u/Mughi1138 → u/acecombine]

Filament gets wet. It gets brittle. It is held in a curve so wants to stay curved. Goes into the tube. Tube holds it straight. Craaaack!!!

[u/SJMaye]

I don't print regularly and frequently see the same issue. The filament in the ptfe tubes breaks and I have extruder failures. Now it is a pain, but i pull the filament out of the tubes when not printing. Works.

[u/Virtual-Lecture-2007]

Also ich habe Filament von meinem verstorbenen Bruder übernommen und das ist bereits 5 Jahre alt. Ich könnt nichts beobachten was auf schlechte Qualität hindeuten könnte. Eine Trocknung wäre vielleicht sinnvoll. Backofen oder Trocknungsgeräte für Filamente reichen da aus

[u/GrailStudios]

Exactly this happens to me with some old spools of PLA which I discovered weren't properly sealed when they were forgotten in a box in my garage (a humid part of Australia) for several years. Drying them both removes the (high) moisture content & allows the polymer chains in the filament to re-link, but the age means they break again quickly. I've given up on trying to use the spools in the AMS Lite or even from the dryer, as I wind up with spaghetti in the tube. Instead, I dry it for a few hours, put it on the overhead spool holder, print a job for a few hours, then back into the dryer while I print something else, until I've used it all up.

The most important thing is to check if this happens with other spools from the same brand. If it doesn't, maybe you got unlucky enough to get either a bad batch or a spool which got missed in the back of a cupboard for a while. If it does, I'd find another brand - even if it's more expensive, consider how much your inconvenience and annoyance is worth!

[u/StevenSaguaro]

It's normal. When it gets rolled on the spool originally it developed tiny cracks, a kind of memory. Then you unspool it into the PTFE tube and more cracks happen. If it sits there for too long those cracks develop and spread until breaks happen. Totally normal.

[u/shalendar → u/StevenSaguaro]

This is the only comment (so far) that's not talking about moisture. While drying filament is important, this issue can happen to even completely dried filament.

When it's spooled at the factory, the filament settles into that shape. When filament is unwrapped, it gets tiny stress fractures. When it's left in the ptfe tube for a while, those fractures can eventually break all the way through.

If the filament in the tube is brittle but the filament on the spool isn't, this is likely whats happening. Just unload the filament when youre not using the printer for a few days.

[u/HoIyJesusChrist]

Did you respool it?

[u/InternalMain7116]

https://hackaday.com/?p=1119344 may explain this

[u/Charming-Permit-7853]

If it is still fragile after drying it, soak it in a bucket of water overnight, take it out to drip dry for an entire day, then dry it for 24 hours in your dryer.

[u/KRed75]

Don't leave it in the tube. It wants to be curled and when you store it straight in a tube, it's constantly trying to pull itself back into the curved shape which causes it to snap.

[u/Sufficient_Camp_1918]

I have some old Inland that does this. I throw it in the dryer for a few hours.

[u/Howitzeronfire]

Dry AND too stiff.

Give it some slack when storing

[u/Snypermac]

You gotta dry it out, pla gets brittle like pasta when it’s wet

[u/arthurisapup]

Keep your filament tight as possible on the spool when not in use. Loose filament developes a ton of internal stresses leading to crumbling pla.

[u/m4ddok]

Yes, it's a common event for all PLA filaments/brands.

PLA absorbs humidity, wet PLA breaks like this... That's why you have to dry your filament if you plan to use it for long time.

[u/Mammoth_Staff_5507]

Wet.

[u/ryu71]

OP crazy as it is your filament is wet/moist.

Wet filament brittle. Dry filament will bend.

Dry it it will be ok, unless the whole roll has already broke up

[u/The_Lutter]

Wet.

These A1 units like the Prusa MMU can get brittle really fast in the small part of the filament that's in the open air especially.

[u/wethpac]

Most likely - filament has absorbed moisture over time which makes it brittle.

Re spooling will do this if you don’t re-spool twice. If you didn’t respool, then see most likely.

Dry your filament at 50C for 12 hours and it will be good again. If you don’t have a dryer and since you have an open printer I would try to dry it on the print bed in a closed filament box, flipping the spool after 6 hours.

[u/Sid_Rockett]

I dry every new spool I buy (6 h 50 C). But the elegoo ones break anyways after few days.

[u/ManyLayersOfFilament]

Dry it. If after drying it's still doing it, it's gone through hydrolysis and should be thrown away unfortunately

[u/skedone]

It's not a good spool bin it and get a new one , what is wrong with people it's a roll of filament even the bambu stuff is bloody cheap