A smaller and cheaper open source brushless motor
Already have an account? Log in.
To make the experience fit your profile, pick a username and tell us what interests you.
My PCB-Motor is made from a 6-pole stator printed on a 4-layer PCB and a 4-pole 3d printed rotor. Its has an outer diameter of 16mm and is rated at 1 watt.
I had this idea when I was trying to design a small compact drone. The PCB motor is much cheaper than other micro brushless motors and also easier to assemble. My goal is to make the rotor part of the BOM and mounted just like any other component on a PCB.
VIDEO
HACKADAY SUPERCON DEMO
Open Source Files - https://github.com/CarlBugeja/PCB-Motor-v4
This video shows my attempt in trying to design a rotor-flux brushless pcb motor prototype:
How fast can my PCB Motor go?
Check out this teardown of the CORE-PCBMotor!! I came across this motor a few months ago, after a few people who saw my design sent me their website's link. There's not much information on it and its also patented but this guy managed to take it apart and review it.
http://build-its-inprogress.blogspot.com/2018/12/core-outdoor-power-pcb-motor-teardown.html
I have no idea why they decided to use it for a lawn trimmer (there's much more interesting applications) but its very interesting to see how it was designed, the way the windings are connected and that it has sufficient torque to rotate a blade!
My SUPER tiny 6-layer PCB Motor is spinning! Here's the full video describing how I designed it:
My original 4-layer PCB motor had a 16mm diameter. By adding two extra layers I was able reduce the number of turns per layer and get it to 11mm. The total height of the motor is 3.6mm and its weight is 0.5 grams.
No space is lost in this pcb! Each coils have 3 vias to connect the in-between layers. These forced a triangular shaped stator poles, which utilize the magnetic field area more efficiently.
The tiny rotor design has four press-fit 2mm n52 magnets and a 3mm bearing. This new design has the shaft soldered onto the stator, so it is fixed and don't rotate with the rotor.
I had chosen to go with this design because of two things:
1. I couldn't find a bearing small enough to fit in the middle of the stator.
2.I'm not planning to use a shaft. Customized 3d-printed rotors makes much more sense.
The phase resistance of this motor was measured to be 15ohmsand its getting to 85℃ with a 4V supply, so it should be perfect for a 1s lipo.
This video shows how i designed my PCB Motor's ESC and what where the challenges involved in getting my speed controller to work.
This is its schematics:
It has a PIC16F1503 as the main controller and a triple half bridge driver STSPIN230, to control the three phases of the motor. These are both powered from the same supply, to avoid having an extra power wire or on-board regulator, reducing the cost even further. I filtered the digital circuitry supply from an LC filter to attenuate any noise the motor can generate. It can operate from a 5V to 2.6V supply and draws around 220mA in total.
As i explained in my previous project logs, the back emf generated from my pcb motor was too weak to implemented a sensorless speed controller. So i decided to use a hall sensor to provide feedback to the microcontroller and then implemented a speed closed loop speed controller.
The open source gerber files and schematics for this PCB are available for download.
In the beginning of November I will be giving a demo of this project at the Hackaday Superconference so see you there!
Its this simple:
Have you thought about using SMD inductors as coils? Top of inductors would most probably need to be filed down to expose the core. This would make it possible to increase the power
Good project！ and I have also seen a tutorial blog about pcb, maybe you are interesting in it: https://www.nextpcb.com/blog
Your PCB is amazing. https://thebestcbdcreams.com/best-cbd-cream-restless-leg-syndrome/
Nice work dude. Any tutorial? https://thecbdmagazine.com/cbd-for-asthma/
I think this motor could change many things in society. Good work!
Tim
Hey,
For your first 4-layer coil, is there any particular reason you went with the layering order you did?
You go for top->L3->L2->Bottom, just wondering if there was some sort of design reason there
can u make tutorials on how to make 3d print rotors and stators?thx
what are the dimensions of the SMF681X-ZZ Bearing. Can you reply sap this is for my science project and i need to use a pcb motor becuase it a cheap and small motor to make. Thank you so much Carl.
Hi, Carl:
Your PCB motor is really amaizing.
I think that perhaps you can improved the torque using flex-PBC coil.
hi. I wondered if you could get one of these to spin at much lower RPM. I am in need of this design to build a remote foot switch operated motor to be placed over a volume potentiometer. Specifically for guitar effects pedal.. I believe it is a very sought after use for this sort of motor. Would you like to collaborate in a busines venture? My email is martin.soundman@gmx.com
hello Carl,I did one of your steps, ESC version.
When I prepared all the devices, I found that I did not have MCU program.
So, I want to say, is this program not open source?
Thanks
Have you seen this: http://build-its-inprogress.blogspot.com/2018/12/core-outdoor-power-pcb-motor-teardown.html
"A company called Core makes some unusual electric lawn tools based on axial flux PCB motors. I first heard about them several years ago, and finally picked up one of the motors to take apart."
I just saw the article it very interesting to see how they're designed!
What a great idea! I love how this makes you go to the basics and analyze what really makes a motor and how can you compromise to make a "usable" motor out of unconventional materials? I'd like to try making one of these... I notice the bearing, SMF681X-ZZ, obviously a key component, is about $9 each from Boca bearing. Any idea on lifetime and lowering that cost? Boca doesn't list lifetime data: https://www.bocabearings.com/search?w=SMF681X-ZZ+Bearing
I wonder if this could be adapted to be a low cost local fan for circulating air from a PCB heater.
HI Carl, I love your projects, very creative! Just curious if you have experimented with stacking these things?
You could ~double your torque if you stack a second stator to sandwich ether side of your rotor. Connect the stators together in parallel with the headers
The result would still have your nice flat profile (thicker but no diameter change) and it would support the output shaft on either side making it more robust.
It would prevent you from attatching a fan but the rotor could still be used as a gear/pulley.
Have you considered rebuilding to a switched reluctance motor instead of a bldc? My gut feeling tells me this could be done slightly cheaper and more efficient. What would be required:
- Keep the ferrite sheet in the back
- Ferrite core in each winding
- Replace permanent magnet with reluctance core patterns to match the amount of windings. Probably 3d printed in ferrite, any high permeability low conductive material. A pattern like one that is shown in the end of this video: https://www.youtube.com/watch?v=qDon7Nrj1Tk
As for the required torque, you might want to consider a 3d printed planetary gear
Carl Bugeja
Mrinnovative
Hey Carl, great project. I am working on prism laser scanner with a BLDC motor see https://hackaday.io/project/21933-prism-laser-scanner . What kind of weight can you spin with this rotor? How planar is the rotation? The most important requirement is that the prisms stays flat and does not wobble during rotation. The size of the prism, depends on the application.