3D Printing Magnetically Conductive PLA?

[verhoevenc]

Just saw this stuff and was wondering if it's worth trying out to have a little fun:
https://www.proto-pasta.com/collecti...ant=1265208548
They have permeability values on the page. I was wondering if that's enough to 3D print, say, some functioning horseshoes to throw a magnet between.
If the stuff magnetizes well enough I think one could get pretty creative in pickup designs?
Throw in that they have electrically conductive PLA too, which could print some interesting shielding/covers... and I really want to experiment!
Thoughts?
Chris

[ken]

I'm curious. Does the electrically conductive material come in useful colors for, say a white Strat pickup cover? Does paint stick to the finished part well, or just chip off?

I think this could make some fun pickup designs... say a bobbin and magnet all in one.

Very interesting

Ken

[verhoevenc]

I'm yet to mess with these materials personally... but they're why I bought my machine hahaha. But from what I know the conductive one is graphene and is black. The magnetic iron is iron colored. I don't know about these materials specifically. It there are numerous articles on sanding, priming, and painting your prints to finalize them.
One of the cool things about these two is they're PLA based, which is what printers that don't even sport a heated bed are capable of printing.
I always have a million projects at once so who knows when I'll get around to this one... but it's in the backlog.

Here's another question though: the material isn't cheap! Printers will print with a certain percentage of 'infill' to save on material and cost... in wondering how a non-solid iron object oriented it's magnetic field when up against a magnet?
Best,
Chris

[rjb]

If the stuff magnetizes well enough I think one could get pretty creative in pickup designs?

Ignorant question from one with little knowledge of 3D printing:
Might it be possible to produce permanently magnetized objects by printing in a strong magnetic field?

-rb

[David King]

rjb, that makes sense to me but what if that field just pulls the ink off target and makes a big mess as a result?
OK it's not ink, it's a thick ooze of plastic with iron particles embedded in it so probably not easy to swing those particles around into a regular orientation in the molten state. I'd also bet that they are not going to stay magnetized since they will probably be a "soft" magnet material being iron. They might make a useful comb type field-focusing core/bobbin/keeper.

[ken]

I was giving this a lot of thought. You don't have to orient an Alnico magnet while it's cooling from a molten state, do you? Perhaps this material will magnetize with a couple of big neos like an Alnico magnet would. Is it possible to get a sample of these materials, say a small cube of this to 'play' with?

BTW... has anyone seen a 3D printer with enough 'resolution' to be useful for making pickup bobbins and covers? I'd love to find one

Ken

[Jason Rodgers]

I was giving this a lot of thought. You don't have to orient an Alnico magnet while it's cooling from a molten state, do you? Perhaps this material will magnetize with a couple of big neos like an Alnico magnet would. Is it possible to get a sample of these materials, say a small cube of this to 'play' with?

BTW... has anyone seen a 3D printer with enough 'resolution' to be useful for making pickup bobbins and covers? I'd love to find one

Ken

My neighbor has a 3D printer that he built (actually, that he and his brother built and had plans to make and sell as kits, but the rest of the 3D printer world moved too quickly around them). He said that most printers aren't fine enough to give a surface that can be considered smooth, requiring sanding to level and polish. But for pickup covers, he said that you'd need to print face down, which could be done on a very smooth or patterned surface, so that might be something you could work with.

[verhoevenc]

What Jason said about facedown being better for "show surfaces" is spot on! Still may require some sanding, etc.

As for samples of this material, absolutely they do. It's not free... but it's also not dropping a ton of cash on a full spool.
Ken, I'd be happy to print out whatever shapes you're curious to play with (cube, rod, etc.) as it will help me learn too. Ship the $4 sample pack Proto-pasta sells, in whatever material you were thinking of, and we can go from there. PM me for details if you wanna try this. I'll likely be playing with these materials, but not in the 'magnetize it' WAY you want to. I also don't own a gauss meter so I'd be useless there too hahahah.
Chris

[David King]

Ken,
The alnico we use mostly is oriented during the cooling phase. The "unoriented" stuff that some like to use in humbucker bar magnets presumably isn't. I don't see any reference on the proto pasta site to magnetizable material just magnetically and electrically conductive.

[Joe Gwinn]

This is finely powdered pure iron in a plastic matrix, with a net magnetic permeability of 5 to 8. In other words, it's more matrix than iron.

Ordinary solid mild steel has a permeability of around 1000. This is a big difference. Don't expect the Composite PLA - Rustable Magnetic Iron to work like solid mild steel.

[verhoevenc]

That's the sort of info I was looking for Joe! I tried reading permeability tables but, admittedly, got pretty lost pretty quick. This is perhaps why they suggest it's use in conjunction with strong neo magnets?
I still think it could be fun though to do things like a horseshoe, claw, etc. that change the shape of the magnetic field a bit... even if not to the same degree as solid metal pieces of the same shape would.
Best,
Chris

[ken]

In other words... any magnetizability it may have is not enough to be useful.

Bummer.

ken

[Joe Gwinn]

That's the sort of info I was looking for Joe! I tried reading permeability tables but, admittedly, got pretty lost pretty quick. This is perhaps why they suggest its use in conjunction with strong neo magnets?

Sounds plausible.

I still think it could be fun though to do things like a horseshoe, claw, etc. that change the shape of the magnetic field a bit... even if not to the same degree as solid metal pieces of the same shape would.

This iron dust in plastic will have one advantage - increases permeability over air without significant eddy-current effects. Soft ferrites also do this.

[verhoevenc]

I noticed these videos on my phone and wondered if I ever posted them. I believe the answer is "no." So here are the results of my 3D printed iron-dust PLA horseshoe pickup experiment. Fair warning, the result is "a bunch of nothing useful." But in case people like that sort of thing... enjoy!
http://www.raygunengineering.com/pic...A/IMG_8596.MOV
http://www.raygunengineering.com/pic...A/IMG_8598.MOV
http://www.raygunengineering.com/pic...A/IMG_8599.MOV
http://www.raygunengineering.com/pic...A/IMG_8600.MOV
http://www.raygunengineering.com/pic...A/IMG_8601.MOV
http://www.raygunengineering.com/pic...A/IMG_8603.MOV
Love how I sat on these for over 4 years hahahaha.
Chris

[verhoevenc]

So the real reason for thinking about those videos again is I was reading a ton of threads for the 50th time on Charlie Christian pickups. jason lollar and a couple of other folks had mentioned the originals had a bunch of iron filings encased in their coil (or was it bobbin?) that explains part of their distinct sound. With the experiment above showing that using this material for any sort of horseshoe or claw is likely (as I was warned) a non-starter... could this perhaps be used to print bobbins for charlie christian style pickups that get "a little closer".
Fair warning: No I'm not trying to perfectly re-create a charlie christian pickup. I've read enough to know I want no part of that (especially since I futz with pickups maybe once, twice a year). However, perhaps a test is in order, just for fun, to see if this material on a bobbin, side by side with a normal PLA printed one, makes any difference at all.
Best,
Chris