• ferromagnetic filament is a FAIL

    DeepSOIC04/16/2016 at 23:58 1 comment

    I did a crude measurement of BlackMagic3D's ferromagnetic filament, and got permeability of about 2. That is hopeless. For more info, see my project #Measuring BlackMagic3D's ferromagnetic filament.

  • ordered ferromagnetic PLA

    DeepSOIC03/26/2016 at 15:11 0 comments


    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...


    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.


    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 =(


    Shipping again. Fingers crossed....


    Filament is in my hands! Cool!

  • vitamins being considered

    DeepSOIC03/26/2016 at 12:31 0 comments

    I really don't want to have to use custom CNC machining to make the motor, so I'm searching for what I can use for making the motor.

    rack with no pinion

    + precision
    + flat-topped teeth. like in steppers.

    - wrong material
    - eddy currents
    - no idea, where to get one

    Threaded rod and nuts

    + precision
    + easy to obtain, cheap

    - wrong material
    - eddy currents
    - spiky ridges. Can be smoothed out, but it's not easy to do precisely.


    + easy to obtain, cheap
    + thin, so can be stacked to get rid of eddy currents

    - wrong material
    - spiky ridges. Can be smoothed out, easier than with threaded rods.
    - not made to be precise, generally.

    Ferromagnetic 3d-print (PLA with iron)

    (thanks to @Lupus Mechanicus for steering me to this!)

    example: http://www.amazon.com/Ferromagnetic-grams-3D-Printing-Filament/dp/B019J1E7GI

    benefits: AWESOME!
    + precision
    + flexibility. Motor can be tailored to fit the printer.
    + no eddy currents

    - bad temperature stability, might require active cooling

  • linear steppers are rare

    DeepSOIC03/25/2016 at 17:15 3 comments

    Quick browse through ebay and aliexpress didn't return any easily obtainable linear stepper motor. So building my own sounds like a good idea.