http://www.blackmagic3d.com/Magnetic-PLA-Filament-p/bm3d-175-mag.htm

I'm very excited about this material. Can make motors, magnets for speakers, maybe even transformers..

Why!! Why they don't make ABS like this? PLA is perfect for printing, but it can only withstand +20-+30 deg.C temperature rise (with respect to ambient +20..+30). That's nothing! ABS is +60..+70 deg.C rise, more than double! Nylon... well... so on...

UPDATE:

As soon as I get the filament, I will measure its magnetic properties. The plan is to obtain the following parameters:
* hysteresis curve
* saturation inductance
* permeability
* dissipation factor

The last three parameters can be calculated from the hysteresis curve, so once I get the curve - I get everything.

Measuring this involves printing a toroid core, winding some wire onto it, connecting it to powerful square wave generator, and measuring current and voltage waveforms. Then, knowing DC resistance of coil, magnetic flux waveform can be obtained. Then, using geometrical parameters of the core, I can construct B-H curve.

Some ~5 years ago, I did this to some cores, because that was the only way (no marking on the core, or no data).

This deserves a separate hackaday project page.

UPDATE2.

Shit happens. There was some strange confusion with shipping. The plastic arrived to St. Petersburg, and was returned back with claims from DHL they don't carry stuff to private individuals. Now, I tried getting in touch with blackmagic3d, no success so far =(((

Stupid delays! They ruin all the excitement about the project =(

UPDATE3.

Shipping again. Fingers crossed....

UPDATE4.

Filament is in my hands! Cool!