>Welcome to /DMG/ DIY Motor Generation!
This is the place to discuss DIY motor designs, showcase your creations, and refine your ideas on motor tech. This thread is a requested offshoot of the "Actuators For Waifu Movement" thread to focus specifically on DIY motors. We will focus solely on DC motors. I will start the thread off by talking about the types of motors and terms associated with electric motors to keep a good reference to look back on. It should be noted that most motors are Radial Flux and not Axial Flux. What is flux? Magnetic flux is a measure of the total magnetic field which passes through a surface. Radial and Axial describes the orientation of the magnetic flux.
Radial Flux Motor
> A radial flux motor is like a cylinder spinning inside another cylinder. The magnetic flux flows perpendicular to the axis of rotation, meaning it moves from the stator to the rotor radially outward or inward. Traditional cylindrical motors (like most brushed and brushless DC motors, induction and steppers) are radial flux motors. Rotor and stator are concentric, with the stator surrounding the rotor. Pros: Well-established, widely used, good for high-speed applications. Cons: Can be bulkier and less power-dense compared to axial flux motors.
Axial Flux Motor
>An axial flux motor is like two discs spinning parallel to each other. The magnetic flux flows parallel to the axis of rotation, meaning it moves along the shaft’s length rather than outward. These motors have a flat, disc-like design where the stator and rotor are stacked on top of each other rather than inside one another. Pros: More compact, higher torque density, and better cooling due to a larger surface area. Cons: More complex to manufacture, higher initial costs.
Kinds of Motors:
>Brushed DC Motor: Uses brushes and a commutator for current switching. Simple, inexpensive, but requires maintenance due to brush wear.
>Brushless DC Motor (BLDC): Uses electronic commutation instead of brushes. More efficient, longer lifespan, commonly used in drones and electric vehicles.
>Coreless DC Motor: Lighter and more efficient than traditional brushed motors, often used in small precision devices like robotics and medical instruments.
>Stepper Motor: Moves in discrete steps, allowing precise control. Used in CNC machines, 3D printers, and robotics.
>Servo Motor: A DC motor with feedback control for precise positioning. Used in robotics, RC vehicles, and automation.
>Single-Phase Induction Motor: Used in household appliances like fans and washing machines.
>Three-Phase Induction Motor: Used in industrial applications due to high efficiency and reliability.
>Linear Motor: Instead of rotating, it moves in a straight line, used in maglev trains and industrial automation.
>Switched Reluctance Motor: A highly efficient and durable motor with no magnets, used in electric vehicles and industrial machines.
>Universal Motor: Can run on both AC and DC, commonly found in power tools and vacuum cleaners.
>Piezoelectric Motor: Uses piezoelectric effect for motion, found in precision instruments and medical devices.
>Synchronous Motor: Rotates at the same speed as the supply frequency, used in precision applications.
>Hysteresis Motor: A type of synchronous motor with smooth and precise operation, used in clocks and timers.
If we analyze all the motor types and configurations here, we can see a single notable design, the Coreless Axial Flux Motor. By combining the Coreless DC Motor with the Axial configuration, we gain significant weight savings and have access to a compact and high power density motor. Further more a Coreless Axial Flux Motor is by far one of the simplest to DIY. Why Coreless? Traditional motors have an iron core in their rotor or stator to guide magnetic fields and improve efficiency. Coreless motors eliminate the iron core, using a winding structure suspended in air or on a non-magnetic support. This results in: Lower weight, Reduced inertia, Lower cogging torque, and Higher efficiency in dynamic applications. Why Axial Flux? Instead of radial magnetic flux, an axial flux motor has flux flowing parallel to the axis. This enables: Compact, disc-shaped designs that save space. Higher torque density, as more of the motor’s active material is utilized effectively. Better cooling, since the large flat surfaces allow for efficient heat dissipation.
Coreless Axial Flux Motor - The Ideal DIY Motor? A coreless axial flux design removes both the iron core and the radial structure, making it lightweight, efficient, and easy to manufacture. DIY Advantages: Simpler to build than traditional motors, no need for laminated iron cores. Less material cost. Magnetic layout is easier to DIY, as axial flux motors can be constructed with permanent magnets on a disc rather than wound stators and laminated cores. Ideal for robotics. Potential Downsides: Without an iron core, magnetic flux leakage can be higher, reducing peak efficiency. Requires strong permanent magnets to compensate for the lack of a core. Complex winding design compared to simple cylindrical motors. Despite these trade-offs, coreless axial flux motors are becoming a major DIY motor trend in areas like lightweight drones and robotics. It’s one of the most promising designs for high-efficiency, high-torque applications with a focus on compact, lightweight construction.
Axial Flux Motor Configurations:
>Single Rotor, Single Stator (SRS) Structure: One stator (copper windings) sandwiched between a single rotor (magnet disc).
>Dual Rotor, Single Stator (DRSS) Structure: One stator positioned between two rotors (magnet discs), one on each side.
>Dual Stator, Single Rotor (DSSR) Structure: One rotor (magnet disc) positioned between two stators (copper windings).
>Dual Rotor, Dual Stator (DRDS) Structure: Two stators with a single rotor in between, similar to DSSR but with an additional rotor.
>Multi-Rotor, Multi-Stator (Stacked Configuration) Structure: Multiple stators and rotors stacked in alternating layers.
The DRSS Coreless Axial Flux would be the most practical and best choice for maximum power