Axial flux motors are used in electric vehicles, robotics, drones, aerospace systems, and compact industrial drives. Their flat structure offers strong torque density in a small package, but manufacturing the stator can be demanding. Axial flux motor winding requires careful control of conductor position, coil dimensions, insulation, and turn count.
Small winding variations can affect resistance, thermal behavior, assembly clearance, and motor performance. For this reason, manufacturers need a repeatable process that matches the motor design, conductor type, and expected production volume.
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Why Axial Flux Windings Require Tight Control
Axial flux machines differ from traditional radial flux motors in their magnetic field direction. Their magnetic flux travels mainly parallel to the shaft, while the stator and rotor usually form flat discs.
This geometry leaves limited axial space for copper conductors. Coil height, inner and outer dimensions, corner shape, and lead position must stay within narrow limits.
Consistency between coils also matters. Differences in turn count or conductor placement can change phase resistance and magnetic balance. Accurate winding helps produce uniform coils that fit correctly during stator assembly.
Common Axial Flux Motor Winding Methods
Manufacturers can use several winding approaches. The correct method depends on stator construction, conductor geometry, voltage, cooling requirements, and production scale.
Preformed Concentrated Coils
Many designs use concentrated coils that are wound separately before stator assembly. A mandrel or forming tool guides the conductor into a specific shape and controls the number of turns.
Manufacturing research describes methods where coils are wound onto shaped tooling, fixed, and then installed into the stator. This approach allows manufacturers to inspect coil geometry before completing the stator.
Preformed coils can also undergo bonding, insulation treatment, or impregnation before installation. That gives manufacturers more control over coil stability during later assembly steps.
Round Wire and Flat Wire
Round copper wire offers flexibility and handles complex bends well. It can be suitable for prototypes, smaller motors, and designs where conductor packing is less restrictive.
Flat or rectangular conductors can improve copper utilization in some stator designs. However, their geometry makes bending more difficult. Excessive force can damage insulation or create unwanted deformation around corners.
Tooling must therefore guide the conductor carefully while keeping its orientation stable.
Coreless and Segmented Designs
Coreless axial flux motors often use shaped coils fixed into a supporting structure. Segmented stators may use individually wound sections that are joined during later production stages.
These structures can provide easier access during winding. However, they may require extra attention during positioning, electrical connection, insulation, and final fixation.
How Automation Improves Coil Production
Manual winding can support prototypes and small production runs. Larger production volumes require better control over operator-dependent variation.
An axial flux motor winding machine can automate functions such as wire feeding, forming, turn counting, winding, and trimming. The referenced production equipment uses servo-controlled winding, a wire-folding module, sensors, PLC controls, and automatic trimming.
Automation also allows manufacturers to save production recipes. Different coil programs can store parameters for wire movement, winding speed, turn count, and forming operations.
This makes repeat production easier and reduces manual adjustment between batches. Sensors can also identify incorrect operating conditions before defective parts reach later assembly stages.
Key Parameters That Affect Winding Quality
Successful axial flux motor winding depends on several connected process variables. Controlling only the number of turns is not enough.
Wire Tension
Wire tension affects both shape and conductor placement. Low tension may produce loose turns or uneven layers. Excessive tension can stretch the conductor or damage its insulation.
The equipment must maintain stable tension as winding speed and wire direction change.
Bend Radius and Corner Formation
Conductor bends deserve special attention, particularly with flat wire. Sharp corners increase mechanical stress and can make the conductor rise away from the intended profile.
The referenced equipment focuses on controlled wire fitting around arcs and corners to reduce unwanted bulging.
A properly designed winding tool should create the required shape without forcing the conductor through unnecessarily tight bends.
Turn Placement
Each turn should sit in a predictable position. Poor stacking can increase total coil thickness and reduce available assembly clearance.
Uneven conductor placement may also reduce the desired copper fill factor. Accurate guiding and controlled movement help keep coil dimensions stable.
Lead Wire Position
Lead length and exit position affect later connection steps. Manufacturers should define these features during coil design instead of correcting them after winding.
Consistent lead positioning simplifies stripping, welding, soldering, or terminal connection.
Quality Checks After Winding
Inspection should cover both mechanical and electrical characteristics. Visual checks can identify damaged insulation, crossed conductors, loose turns, or poor corner formation.
Dimensional inspection verifies coil width, thickness, profile, and lead position. These measurements become especially important when coils must enter tightly controlled stator fixtures.
Electrical inspection can include resistance and insulation testing. Depending on the motor voltage and application, later production stages may also use additional electrical tests.
Published research on axial flux motor production identifies winding, assembly, contacting, testing, and impregnation as connected parts of the stator manufacturing process.
Production data should also be recorded where possible. Machine alarms, recipe versions, cycle information, and inspection results can reveal gradual process changes.
Choosing Winding Equipment for Production
Machine selection should start with the actual coil specification. Manufacturers should define conductor size, material, coil geometry, turn count, target cycle time, and dimensional tolerance.
Changeover requirements also matter. Flexible factories may produce several motor types, so tooling and machine recipes should support practical product changes.
The machine should also fit the wider production process. Winding may connect with wire stripping, electrical testing, coil transfer, stator assembly, or other automated stations.
According to the supplied equipment information, its stand-alone winding system includes an interface for integration with a larger axial flux motor assembly line.
Manufacturers should verify supplier performance claims with their own coil design. Actual cycle time and yield can change with conductor type, winding geometry, quality requirements, and material handling.
Design Coils With Manufacturing in Mind
A coil can perform well in electromagnetic simulations but still be difficult to manufacture. Design and production teams should therefore work together early.
A larger bend radius, for example, may reduce insulation stress. Changing the lead exit can simplify electrical connection. Small geometric adjustments may also improve tool access and reduce winding variation.
Manufacturing methods continue to develop as axial flux applications expand. In 2026, researchers at RWTH Aachen began studying a process for directly winding concentrated coils with profiled litz wire. The project focuses on improving manufacturability while addressing demanding motor applications.
Creating a Repeatable Production Process
Reliable axial flux motor winding comes from combining suitable coil geometry, conductor selection, tooling, machine controls, and inspection. A winding machine cannot compensate for a coil design that is difficult to manufacture consistently.
For companies moving from prototypes toward repeat production, an axial flux motor winding machine can improve repeatability, monitoring, and integration with other production steps. Automation works best when engineers first define clear dimensional and electrical requirements.
A stable process should produce coils that fit correctly, connect easily, and maintain consistent electrical characteristics. That reduces downstream adjustments and gives the finished motor a reliable foundation for efficient production.