brushless motor

68 Articles

Two hands hold an electric motor rotor and a 3D printed coil structure next to each other. A multimeter in the background displays 297.0 mV.

ModuCoil – A Modular Coil For Motor And Generator Projects

October 2, 2023 by 2 Comments

While renewable energy offers many opportunities for decentralizing energy production, it can sometimes feel that doing so on a truly local level remains unachievable with increasingly large utility-scale deployments re-centralizing the technology. [AdamEnt] hopes to help others seize the means of energy production with the development of the ModuCoil.

This modular coil is intended to be used in motor and generator applications, and features a 3D printed structure to wind your copper about as well as a series of ferromagnetic machine screws and nuts meant to boost the field strength. This project really emphasizes the rapid part of rapid prototyping with this version 2 of the coil following only a week after the first.

[AdamEnt] only reached a peak of ~600 mV in the short test of a single coil, but is optimistic the current design could hit 1V/coil given a fully wound coil actually affixed to something instead of just held in his hand. It’s definitely early stages, but we think this could be the start of an interesting ecosystem of motor and generator designs.

If you want to learn more about how those big wind turbines work, look here, or you could check out a 3D printed brushless motor, or where all that copper comes from anyway.

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You Can 3D Print A 12,500 RPM Brushless Motor

June 28, 2023 by 18 Comments

Typically, when most of us need a motor, we jump online to order one from a catalogue. [Levi Janssen] recently had to build his own for a college project, however, and learned a lot along the way.

[Levi] whipped up his brushless DC motor design in OnShape. The motor has six coils in the stator, with the rotor carrying eight neodymium magnets. It’s an axial flux design, with the rotor’s magnets sitting above the coils. This makes construction very easy using 3D printed components. Axial flux motors also have benefits when it comes to power density and cooling, though optimization is outside the scope of [Levi]’s work here.

[Levi]’s video covers both the development of the motor itself as well as the drive circuit, too. The latter is of key value if you’re interested in the vagaries of driving these motors, which is far more complex than running a simple brushed motor. He even gets his motor up to 12,500 rpm with his homebrewed drive circuit.

Making your own motors can help you solve some difficult engineering challenges, like building motorized rollerblades. Alternatively, if winding coils sounds too slow and too hard, you can just use off-the-shelf gear and hack it to make it work. Here, we support both methods.

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Adding A Third Wheel (And Speed Boost) To An Electric Scooter

September 24, 2022 by 7 Comments

The story of how [Tony]’s three-wheeled electric scooter came to be has a beginning that may sound familiar. One day, he was browsing overseas resellers and came across a new part, followed immediately by a visit from the Good Ideas Fairy. That’s what led him to upgrade his DIY electric scooter to three wheels last year, giving it a nice speed boost in the process!

The part [Tony] ran across was a dual brushless drive unit for motorizing a mountain board. Mountain boards are a type of off-road skateboard, and this unit provided two powered wheels in a single handy package. [Tony] ended up removing the rear wheel from his electric scooter and replacing it with the powered mountain board assembly.

He also made his own Arduino-based interface to the controller that provides separate throttle and braking inputs, because the traditional twist-throttle of a scooter wasn’t really keeping up with what the new (and more powerful) scooter could do. After wiring everything up with a battery, the three-wheeled electric scooter was born. It’s even got headlights!

[Tony]’s no stranger to making his own electric scooters, and the fact that parts are easily available puts this kind of vehicular experimentation into nearly anybody’s hands. So if you’re finding yourself inspired, why not order some stuff, bolt that stuff together, and go for a ride where the only limitation is personal courage?

How Far Can You Push A £500 Small Electric Car; Four Years Of The Hacky Racer

June 22, 2022 by 31 Comments

Four years ago when the idea of a pandemic was something which only worried a few epidemiologists, a group of British hardware hackers and robotic combat enthusiasts came up with an idea. They would take inspiration from the American Power Racing Series to create their own small electric racing formula. Hacky Racers became a rougher version of its transatlantic cousin racing on mixed surfaces rather than tarmac, and as an inaugural meeting that first group of racers convened on a cider farm in Somerset to give it a try. Last weekend they were back at the same farm after four years of Hacky Racer development with racing having been interrupted by the pandemic, and Hackaday came along once more to see how the cars had evolved. Continue reading “How Far Can You Push A £500 Small Electric Car; Four Years Of The Hacky Racer” →

Ball Balancing Wheel Puts A Spin On Inverted Pendulums

July 20, 2021 by 18 Comments

If you march sufficiently deep into the wilderness of control theory, you’ll no doubt encounter the inverted pendulum problem. These balancing acts have emerged with a number of variants over the years, but just because it’s been done before doesn’t mean there’s no space for something new. Here, [David Gonzalez], has taken this classic problem and given it an original own spin–literally–where the balancing act is now a ball balanced precariously upon a spinning wheel. (Video, embedded below.) Mix in a little computer vision for sensing, a dash of brushless motor control, a bit of math, and you have yourself a closed-loop system that’s bound to turn a few heads.

[David’s] implementation is a healthy mix of classic control theory with some modern electronics. From the theory bucket, there’s a state-space controller to drive both the angle and angular velocity of the ball to zero. The “state” is a combination of four terms: the ball angle, the ball’s angular velocity, the wheel angle, and the wheel’s angular velocity. [David] weights each of these terms and sums them together to create an input value to adjust the motor velocity driving the wheel and balance the ball.

From the electronics bin, [David] opted for an ESP32 running Arduino, the custom Janus Brushless Motor Controller running SimpleFOC, and a Maix Bit Microcontroller with an added camera running MicroPython to compute the ball angle. Finally, if you’re curious to dig into the source code, [David] has kindly posted the firmware on Github.

We love seeing folks mix a bit of control theory into an amalgamation of familiar electronics. And as both precision sensors and motor controllers continue to improve, we’re excited to see how the landscape of projects changes yet again. Hungry for more folks closing the loop on unstable systems? Look no further than [UFactory’s] ball balancing robot and [Gear Down for What’s] two wheeled speedster.

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Tiny PCB Motor Robot Is Making Its First Wobbly Moves

May 30, 2021 by 10 Comments

[Carl Bugeja] has been working on his PCB motors for more than three years now, and it doesn’t seem like he is close to running out of ideas for the project. His latest creation is a tiny Bluetooth-controlled robot built around two of these motors.

One of the main challenges of these axial flux PCB motors is their low torque output, so [Carl] had to make the robot as light as possible. The main board contains a microcontroller module with integrated Bluetooth, an IMU, regulator, and two motor drivers. The motor stator boards are soldered to the main board using 90° header pins. The frame for the body and the rotors for the motors are 3D printed. A set of four neodymium magnets and a bearing is press-fit into each rotor. The motor shafts are off-the-shelf PCB pins with one end soldered to the stator board. Power comes from a small single-cell lipo battery attached to the main board.

The robot moves, but with a jerking motion, and keeps making unintended turns. The primary cause of this seems to be the wobbly rotors, which mean that the output torque fluctuates throughout the rotation of the motor. Since there are only two points of contact to the ground, only the weight of the board and battery is preventing the central part from rotating with the motors. This doesn’t look like it’s quite enough, so [Carl] wants to experiment with using the IMU to smooth out the motion. For the next version, he’s also working on a new shaft mount, a metal rotor, and a more efficient motor design.

We look forward to seeing this in action, and also what other application [Carl] can come up with. He has already experimented with turning it into a stepper motor, a linear motor, and a tiny jigsaw motor.

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The Dynamotor Simplified

April 11, 2021 by 28 Comments

[Robert Murray-Smith] doesn’t like the price of inverters to convert DC to AC. That led him to build a dynamotor, or what is sometimes called a motor-generator set. These devices are just DC motors driving a generator. Of course, motors can also be used as generators and [Robert] had a stack of brushless motors in the form of PC fans. A two-fan dynamotor was born.

The brushless motors are attractive because, traditionally, the brushes are what usually fail on a dynamotor. The fan that will act as a generator needs some surgery, but it is simple. He scraped off all the control electronics and connected wires to the coils to form a three-phase generator. There’s no need for the fan blades in that configuration, either. If you were using ordinary motors and a generator, getting shafts concentric would be an important task. With the fans, it is simple to just line up the mounting holes and you get perfect alignment for free.

How does it work? [Robert] has a second video showing the output on a scope. You can see both videos below. The dynamotor makes a good-looking sine wave, probably much better than most reasonable-priced solid state inverters. He didn’t mention how much current he could successfully draw, but it probably isn’t much. You’d also need a transformer to replace a commercial inverter that would put out line voltage, so that would be some more loos in the system. On the other hand, if you wanted AC at a lower voltage, you might just replace all the transformers, if you were building a piece of gear yourself.

We’ve looked at how these things work in some detail. There were common in old tube radios, particularly military ones.

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