Powerful, Professional Brushless Motor From 3D-Printed Parts

Not satisfied with the specs of off-the-shelf brushless DC motors? Looking to up the difficulty level on your next quadcopter build? Or perhaps you just define “DIY” as rigorously as possible? If any of those are true, you might want to check out this hand-wound, 3D-printed brushless DC motor.

There might be another reason behind [Christoph Laimer]’s build — moar power! The BLDC he created looks more like a ceiling fan motor than something you’d see on a quad, and clocks in at a respectable 600 watts and 80% efficiency. The motor uses 3D-printed parts for the rotor, stator, and stator mount. The rotor is printed from PETG, while the stator uses magnetic PLA to increase the flux and handle the heat better. Neodymium magnets are slipped into slots in the rotor in a Halbach arrangement to increase the magnetic field inside the rotor. Balancing the weights and strengths of the magnets and winding the stator seem like tedious jobs, but [Cristoph] provides detailed instructions that should see you through these processes. The videos below shows an impressive test of the motor. Even limited to 8,000 rpm from its theoretical 15k max, it’s a bit scary.

Looking for a more educational that practical BLDC build? Try one cobbled from PVC pipes, or even this see-through scrap-bin BLDC.

23 thoughts on “Powerful, Professional Brushless Motor From 3D-Printed Parts

  1. OK, so how long before we start seeing injection molded, mostly plastic motors from China? :D

    Also, since he has a 3D printer, axial flux motors might be worth exploring, as they can remain efficient even without a ferromagnetic core for the windings…

    1. I’ve already seen some at hobby king even a few years ago. Those particular motors were crap but worked okay with light loads.

      If there’s a way to do it right there might be a weight advantage. Might have serious cooling issues though.

        1. why not? By axial flux you mean the one that looks like a pair (or three) disks, don’t you? you still need poles and stuff to minimize the airgap, don’t you?

  2. This looks like a great motor, I’m impressed that you can DIY something that works so well!

    One thing I worry about is heat. Motors get hot, and plastic doesn’t like being hot. Using this in a project would mean keeping it below about 80C, which could complicate matters.

          1. Actually, I’m with oodain on this one. The overall quality of the print is important, of course, but the glass transition temperature depends on the material used, not the quality of the print. PLA has a glass transition range of a little over 60c, You don’t need it to be molten to deform (I left a spinner in my car yesterday, it was deformed and it never got over 21c all day). PETG is a little more forgiving at around 90c, but it isn’t ideal.

          2. i have used the UM2 and several sub1k printers, i would never in a million years pay the asking price for the UM2, i have seen 600usd printers that did a better job out of the box and the second one starts tinkering all bets are off.

  3. What a beautiful job. The second video is well worth watching. It’s a great education of winding an armature as well as his method of quantifying the magnets. Super interesting and highly professional.

  4. Nice job, though, contrary to standard electric motor this one have an external rotor, This means all the outer shell rotate. Some care should be taken to avoid object contact with the shell.

    1. Pretty sure if someone is capable of designing/making this from scratch, they will be aware of the rotor configuration and will be capable of safely operating it.

  5. I’d want to buy many more magnets than required then sort them all for as identical mass and force as possible. There should also be some way made to balance the rotor without any magnets installed. Can hear by the sound of it without a prop that it has some vibration.

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