“Virtual ignore” works just as well.
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Inconvenient truths don’t warrant such animosity.
Well, I’m waiting to hear back from my friend at Thermo-Fisher, I think he ought to be able to shoot a sample for me. Perhaps next week. I will of course post what he finds (assuming he can do it for me).
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Bizar! Only the 30% iron filled pla i have does that!
I tested it with a 12kg magnet on my BL PETG-CF and its not magnetic. But my BL PAHT-CF is.
I tested some BL PA-CF that I had printed 9+ months ago. It was the one included in the KS. It’s not magnetic. Some batches might have iron filings in them? Someone mixed up carbon fiber powder with iron powder is my best guess.
Wouldn’t it be easiest just to dissolve some of the filament and see what is in it? The iron isn’t going to be dissolved in the plastic, it’s going to be a powder or filings. At the same time you’d get to see if there is any CF in it. DMF should work, I’m guessing it won’t attack the iron.
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Dissolving the filament is easy. But how would you “see” what’s in the resultant blob of goop?
I think powdered metal, or filings, would be unlikely since particulate large enough to see with the naked eye will be particulate large enough to plug the nozzle and make it impossible to print. Assuming the culprit is Iron, I suspect it’s going to be “nano” particulate. I don’t think anything would be distinguishable to the naked eye.
My friend said he could get a SEM done for me. But it’s kind of a PITA for him so I’m undecided on whether or not to take him up on the offer. Still thinking about it…
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I would have loved to test this, but I don’t have any PA-CF. I have access to a lab and a Xray machine that’s capable of finding all the elements in a peculiar sample.
If people have access to some chemistry equipment, they could try dissolving the filament in some solvent. They could add muriatic acid and titrate the potential Fe2+ using potassium permanganate. We could know exactly how much is in there !
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Fortunately there is a device which can attract and aggregate ferrous particles that are suspended in a liquid, even if they are nano sized.
Where are you located? Someone can send you some, if you are in the US I will.
I’m in the EU, so it wont be possible 
Is it magnetic when its on the spool? Maybe the nozzle is depositing metal
Already discussed.
Short version: Yes it is, and no it isn’t. 
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I have some Polymaker PA-CF I can try as well.
Will it set off customs alarms? I dont want a team looking up my bum because i made a plant pot for my Nan
Well that seems to dismiss the print bed aligning the polymers theory then?
Going with my gut here, this is a result of the manufacturing process. Something is either being added to the mixture with ferrous properties deliberately as part of the recipe, or introduced unintentionally as a byproduct of whatever process BBL is using.
I just checked a roll of Polymaker PA12-CF and PA612-CF and my two magnet stack did not stick to either one, not even the slightest hint of attraction.
I think so. The print i made where i discovered this was tall, 200mm or so. It was just as magnetic at the top.
It’s almost certainly “doped”, the questions are “with what” and “why”.
I’ll probably send a sample to my friend to have it run through SEM. Just likely to be a few weeks before i get results back. That’ll give us the “with what” part anyway.
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It might be worth testing a piece cut from the roll and a sample that has been printed to compare.
Based on my observations, as well as feedback from others, I don’t think there’s any doubt that it’s coming off the spool this way, vs. being transformed somehow when it’s printed. But I can include a piece off a print run, some support material or even some poop, along with a piece of filament when I send the sample out…
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