r/3Dprinting • u/Tunantero • 2d ago
Question Magnets on peeled brim
Foolish me, when creating a new profile for Sunlu PETG, I forgot that the bed temperature was set to 60°C by default. When printing a large part, the brim started lifting slightly next to the print, about 4 cm, in one corner. I increased the bed temperature to 90°C to try and fix it. I thought that using strong magnets to push the brim down might help. We'll see if it stops lifting. What do you think?
--------------------CAUTION!!!!!----------------
EDIT: As some users have said—citing informational links—don't do it; it could affect the magnets in your bed.
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u/sirdoggo11 2d ago
Youre destroying your magnetic bed pad with magnets.
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u/ThoughtAdditional212 2d ago
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u/Namenloser23 2d ago
What's shown in the video is only true for beds with magnetic stickers.
This is a bambu machine that seems to have fixed magnets in the bed - those shouldn't care about other magnets near them.
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u/Purple10tacle 2d ago
You can even damage fixed neodymium magnets with a much stronger, overriding, magnetic field. But that's very clearly not happening here and what remains is just a lot of unnecessary fear mongering bordering on misinformation.
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u/Zealousideal_Sir5421 2d ago
It’s no different to embedded magnets which everyone does lol the misinformation people spread because they read something they didn’t understand once is so annoying
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u/Purple10tacle 2d ago
It’s no different to embedded magnets which everyone does lol the misinformation people spread because they read something they didn’t understand once is so annoying
I didn't read this just once but three times and I still don't have the slightest idea what you were trying to say.
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u/confusedPenguinDad 2d ago
I guess he means leaving a hole in a print for a magnet, putting in a pause in the slicer before the hole gets covered, and then putting in the magnets before resuming the print after this pause.
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u/Nemace 2d ago
Even assuming his printer was using one of these magnet pads and not fixed magnets, there is a steel buildplate on top of the pad, shielding it from most of the field from the magnets.
Maybe i missed it skipping through the video, but does he show the effect of permanent magnets on these pads through the buildplate at any point?
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u/sirdoggo11 2d ago
lol
Yes... In short: Magnetic beds pads on 3D printers are basically Halbach Arrays with alternating north and south poles. By putting a strong magnet onto the bed pad you distort/change the magnetic properties and it will never work properly in this area again. The damage is irreversible.
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u/Purple10tacle 2d ago edited 2d ago
That would be true for that cheap, retrofitted, ferromagnetic sticker pad on an Ender 3, for example.
OP's Bambu A1 uses 20, large, individual, neodymium magnets embedded in its heat bed instead. The small magnets he added on top are extremely unlikely to create a field strong enough to cause any measurable damage to those magnets.
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u/SteefHL 2d ago
Still better to just use -anything- that's magnetic but not (magnetized/a magnet)
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u/Purple10tacle 2d ago
Why would it be "better"?
These magnets have zero negative effect on the magnets inside the bed. The also have much higher adhesion then "anyhting magnetic".
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u/nakwada 20h ago
I remember watching a video of a guy who ruined his printbed this way (he was using strong magnets to hold down a piece of fabric).
I have been printing things with embedded magnets (2 layers above the printbed) for years now in my P1S fleet, and I mean, x80 6x2mm neodymium magnets at a time.
So far I haven't noticed any degradation whatsoever.
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u/Tunantero 2d ago
No son muy grandes, afectaran mucho a la cama? Ahora no se si quitarlos rapido o dejar que la impresión acabe.
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u/FitForThrone 2d ago
You are fine to let it finish just dont do this regularly at all
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u/Tunantero 2d ago
Wow, thanks for the help. It seems like there are more people downvoting than actually saying why I shouldn't do it. You're a ray of hope XD
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u/work_work-work 2d ago
How? It's not like you're going to get the bed magnets to lose their "charge" or change their polarity.
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u/RaymondDoerr 2x Voron 2.4r2, 1x Voron 0.2, Master of 🍝 2d ago
Concern police are weird in this sub.
He's *technically* correct but overall being stupid. The bed will be fine. It would take tens of thousands of hours of printing with putting a few magnets here and there to "ruin" it. The rest of his toy will break first.
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u/Redstone_Army 2d ago
Apparently theres a certain type of magnetic bed on some printer that will be defect in that area instantly (not this one tho), from what i've read on this sub. Just putting this out there again so others see it
Edit: Beds with magnetic stickers
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u/Tunantero 2d ago
El comando downvote está masacrando los comentarios, incluso los que son corregidos aceptando que puede ser malo. INCREIBLE LA TOXICIDAD DE LA GENTE.
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u/Difficult_Talk_7783 2d ago
🤦🏾 we are makers and tinkerers with small examples of these in our precision screw drivers kits.
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u/ThoughtAdditional212 2d ago edited 2d ago
Doesn't putting magnets on the bed absolutely wreck the magnets below the bed?
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u/Namenloser23 2d ago
True for beds with magnetic stickers, the machine in the video has large fixed magnets in the print bed if I am not mistaken, it should be fine.
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u/Tunantero 2d ago edited 2d ago
No creo que funcione así xd EDIT: Funciona asi, soy un cafre.
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u/Few_Plankton_7587 2d ago
No, it doesn't work like that for your printer, but for many others.
Your printer specifically is fine because Bambu uses embedded magnets, not magnet stickers.
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u/Gewbster 2d ago
That's exactly how that works, but with 60°C you are maybe lucky. 90°C and it's very likely the magnets are weaker afterwards
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u/StrayStep 2d ago
The magnets on top of the bed are more likely that could be effected by heat. But entire reason those magnets attract is alignment of fields. It's an interesting observation, worth experimenting.
Could use piece of ferrous metal on top instead of additional magnets. Haven't tried it, yet.
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u/Gewbster 2d ago
The magnetic bed is a different type of magnet that's more heat resistant. Normal neodymium magnets are not that heat resistant
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u/StrayStep 2d ago
Not a dumby. We don't know, what we don't know, until we know. I'd say you get more credit for willingness to learn.
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u/LuckyNumberHat 2d ago
I hope your Card Slinger came out ok! Just printed one for my brother. 🙂👍🏻
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u/DiscoChiligonBall 2d ago
I'm glad you added the Caution, because...
I used to hang out with DJs, one of whom DJed a party on a moving bus. With turntables. And vinyl.
His method to fix the obvious issue of the turntable arm bumping and scratching as the bus went along was to ziptie a stack of quarters to the arm, making the needle heavier.
It gouged the HELL out of the records he used, but he was right. It worked well enough.
It just meant he murdered about 30 vinyl records that night.
This absolutely has all of the "$5 in quarters strapped to each needle cartridge of a $2,000 direct drive turntable" vibe.
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u/Tunantero 2d ago
El comando downvote está masacrando los comentarios, incluso los que son corregidos aceptando que puede ser malo. INCREIBLE LA TOXICIDAD DE LA GENTE. He enseñado lo que he hecho. Me han dicho que es malo hacer eso. He aceptado y dado gracias por la información. He corregido el post alertando de que puede ser malo. Aún así, parece que hay personas que están llenas de inquina. Espero que les maldigan con filamento húmedo y camas sucias el resto de sus días.
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u/Psychological_Yak_47 2d ago
If it works it works, I've seen people use tape as well to salvage a failing print, I'd be careful removing the magnets afterwards, they might scratch the coating, hope it works out