Filament broke

[terrypin]

My 1.75mm PLA filament broke during a print with my Ender 3 V2. The remaining amount on the 1kg reel was then difficult to insert. I thought this was because it was brittle and stiff, like a coiled spring. Instead of going into the bowden tube it was coming out sideways from the pulley/gear section.

But on thinking further I guess this was actually because there would have been filament remaining, blocking the upper end of the tubing? Does the springiness of the filament matter once it's safely into the tube?

Meanwhile I've started a fresh reel, but there's still about 25% left on the first one, so I need to be confident I can use it.

Are breakages like this rare? This reel came with the printer in early March. What is a typical lifetime on the reel holder in my home office?

Terry

 

[andy_mk3]

It usually breaks if it's been left out in the open and has absorbed moisture, they should always be stored in a dry place when not in use. You can dry it out in a food dehydrator or similar and will be able to use it again.

 

[terrypin]

Thanks Andy. But I don't think that can be the cause in this case. As mentioned, it's lived in the corner of my office for four months.

 

[andy_mk3]

OK.

 

[Cadder]

How are your reels mounted? Could it be that the nozzle direction is not tangential to the filament reel?

Or might the feeder head be struggling to grip and the filament just popped out? I had to clean the gripping rollers on mine as they collected material over time.

I could be way off.

 

[Haze]

Thanks Andy. But I don't think that can be the cause in this case. As mentioned, it's lived in the corner of my office for four months.

If it's going brittle, then it's either age, moisture, or poor quality filament

If you left the filament loaded on your printer for 4 months, then this is why it has gone brittle

 

[terrypin]

How are your reels mounted? Could it be that the nozzle direction is not tangential to the filament reel?

Or might the feeder head be struggling to grip and the filament just popped out? I had to clean the gripping rollers on mine as they collected material over time.

I could be way off.

Thanks, but reel is mounted correctly (although not ideally on the Ender 3 V2 IMO, as it passes close to the vertical Z thread). Rollers also seem OK.

 

[terrypin]

If it's going brittle, then it's either age, moisture, or poor quality filament

If you left the filament loaded on your printer for 4 months, then this is why it has gone brittle

It does seem to come down to the brittleness, but I'm surprised to hear that it should deteriorate like that, kept indoors, in as little as 5 months (installed early March).

Can I restore its condition by warming in the kitchen oven? If so, what temperature and for how long? Or what about unwinding and stretching sections of say 5m between two securing points for a few hours, repeating until end is reached, then rewinding?

 

[Haze]

You have nearly finished the spool, I would not bother, learn by your mistakes and don't leave it on the printer, you should remove when you have finished and store it properly

 

[andy_mk3]

So after dismissing my idea turns out I was right

 

[terrypin]

You have nearly finished the spool, I would not bother, learn by your mistakes and don't leave it on the printer, you should remove when you have finished and store it properly

Can you clarify your recommendation please? Are you saying that experienced users (I'm only 5 months into the hobby) withdraw the filament after every print? Or only if it's not expected to do another print for a 'long' time? What, a day? A week? A month? And then what do you mean by "store it properly"? Would a sealed plastic kitchen bin bag be OK?

My estimate (from weighing) was that there's about 25% or so left, so I'm reluctant to bin it.

No observations from anyone on my other questions please?

"Can I restore its condition by warming in the kitchen oven? If so, what temperature and for how long? Or what about unwinding and stretching sections of say 5m between two securing points for a few hours, repeating until end is reached, then rewinding?"

 

[Haze]

I leave mine on the printer for a few days at the most, needs to go in to a sealable bag, with desiccant bags inside

Would not really try baking it, but have a look on Google for information on how other people do it

 

[terrypin]

Thanks understood. I suppose I’ll have to get into a similar habit then, removing the reel whenever I have no imminent intention of another print.

In a spirit of experiment I think I’ll risk carefully trying say 40 C for an hour in the electric fan kitchen oven. Sounds like my only hope of recovering such a significant length of this brittle PLA.

Presumably no one has come up with a ‘softening’ liquid or spray of some sort? A wilder thought: what about a DC or AC voltage applied across across each end with croc clips? If there really is a significant water content, that could theoretically warm it and therefore dry it out? Hmm, accessing the inner end without unwinding the entire 25% might be tricky.

Looking at some of the commercial ‘dry boxes’ etc, but most seem very expensive and presumably targeted at professionals rather than hobbyist beginners like me. I’ll try a plastic bag on this new reel and see how it goes. Printing frequency should be higher over next few months so that may help.

 

[mikedigitales]

I don't print super frequently, and found a filament drier really useful. I picked up a sunlu filament drier from Amazon when it was on sale for £40 and moded a fan to sit inside it.
For example I went back to use a roll of silk PLA that I'd put away in a resealable bag a few month back. It was printing bad, and not sticking properly to the bed on first layer. Gave it 6 hours or so in the filament drier, and it's printing perfectly again. I suspect most of the time you hear people moaning about bad batches of filament, all it needs is a decent dry.
Be careful if using an oven, the temperature control at low temps (e.g. 50 C) is normally pretty bad, and you might end up with a plastic blob on the bottom of the oven.

 

[terrypin]

Thanks, I'll explore that approach. Yes, my fan oven's first number on the temperature knob is 50 C. With it barely off its zero point, an external digital thermometer's probe near the reel is currently displaying a steady 38.8 C. Bit low so I'll nudge it up a bit.

Couldn't access the inner end but the resistance of about 20cm gave no reading under 2M ohms, so I'm not hopeful about that line of pursuit.

 

[bulb66]

Filament dryers are a con, the eSun and Sunlu ones don't get hot enough to do the job. Get a food dehydrator much better and that's what I use.

And yes I remove filament from the printer after use unless I'm printing less than 24hrs later. I use sous vide cooking bags with a hand pump to store my filament.

 

[terrypin]

Looking at many dehydrators. Those I’ve seen appear to have shallow shelves arranged vertically. Could you name or link the one you use please?

 

[terrypin]

I don't print super frequently, and found a filament drier really useful. I picked up a sunlu filament drier from Amazon when it was on sale for £40 and moded a fan to sit inside it.

I like the sunlu dryer, but as you and bulb66 point out the uneven temperature seems a serious flaw. Could you identify the fan you used please, which I assume is very small?

 

[mikedigitales]

I like the sunlu dryer, but as you and bulb66 point out the uneven temperature seems a serious flaw. Could you identify the fan you used please, which I assume is very small?

Sure I used this design https://www.thingiverse.com/thing:4729474 as a starter for the corner mounted fan - but modified it a bit as I decided to use a 24v fan - so didn't use a buck converter. From memory I opened up the casing and added some cabling to tap into the power coming into the drier (for the fan) and while I was at it moved the temperature sensor from it position under the heating elements to nearer the fan. Just means it can move the heat around the box properly, and the whole box reaches the displayed temperature, not just the bottom bit. It wasn't too difficult to do, and I chose to take it on this way as I didn't have much space for one of the big round dehydrators in my work area.

 

[terrypin]

Thanks, I’ll take a close look at that.