The Kailh Nexus Switch is the industry’s first mass-produced switch to integrate a mechanical metal contact leaf with Hall-effect magnetic sensing within a single unit. The core engineering challenge lay in preventing mutual interference between the magnet’s magnetic field and the physical structure of the contact leaf when they coexist within the same switch stem space. Kailh’s solution was «physical isolation combined with functional decoupling»: the leaf and the magnet are positioned in separate zones within the stem—the leaf handles tactile feel and mechanical actuation, while the magnet handles Hall-effect sensing, ensuring neither interferes with the other. However, this design comes with a structural trade-off: currently, the Nexus Switch can only enable dual-mode switching on specialized PCBs (such as the Lofree HYZEN); installing it in a standard mechanical keyboard or a dedicated magnetic-switch keyboard prevents it from fully utilizing the potential of its dual «hearts.»
I. Why a «Two-in-One» Design?
Durante años, los interruptores mecánicos y los interruptores magnéticos han ocupado pistas paralelas. Los interruptores mecánicos se basan en el contacto de la hoja metálica para el accionamiento, ofreciendo protuberancias táctiles y el sonido característico de la hoja, pero sufren de puntos de actuación fijos y una vida útil limitada por el desgaste del punto de contacto. Los interruptores magnéticos utilizan sensores Hall para detectar cambios en el campo magnético, admitiendo funciones como Rapid Trigger, DKS, SOCD, 0.01mm precisión de actuación y durabilidad superior, pero ofrecen una sensación lineal y carecen de retroalimentación táctil física.
Las debilidades de uno son precisamente los puntos fuertes del otro. Kailh eligió combinar estas dos rutas en un solo interruptor: la hoja metálica conserva la textura de escritura y la retroalimentación inferior hacia afuera de un interruptor mecánico, mientras que el imán y el sensor Hall proporcionan el recorrido ajustable y las características orientadas a los deportes electrónicos de un interruptor magnético.
II. La naturaleza del problema de la interferencia
Colocar un imán y una hoja de contacto dentro del mismo vástago del interruptor introduce varios riesgos de interferencia física.
La interferencia del circuito magnético es la principal preocupación. La hoja de contacto está hecha de una aleación de cobre; mientras que el cobre en sí no es magnético, la hoja se deforma durante el accionamiento. Si la posición de la hoja o la trayectoria de movimiento la acerca demasiado al imán, teóricamente podría causar perturbaciones menores en la distribución del campo magnético, afectando así la precisión del sensor Hall en la lectura de la posición de recorrido.
La competencia por el espacio interno es el segundo problema: en los interruptores mecánicos tradicionales, el espacio dentro del vástago acomoda solo la hoja de contacto metálica y el resorte, mientras que en los interruptores magnéticos, alberga solo el imán y el resorte. El interruptor Nexus, sin embargo, requiere alojar ambos sistemas dentro del mismo vástago manteniendo las dimensiones estándar del interruptor MX y una distancia total de recorrido de 3.5mm.
La interferencia acústica presenta un tercer desafío: la presencia de la hoja de contacto altera la cámara acústica interna; cuando el imán y la hoja coexisten, el perfil sonoro y las características de resonancia cambian.
III. La solución de Kailh: aislamiento físico y desacoplamiento funcional
Durante el desarrollo del Nexus Switch, Kailh estableció dos objetivos claros de ingeniería: garantizar que no haya interferencia entre el campo magnético del imán y la hoja de contacto, y mantener la compatibilidad dimensional a pesar de integrar capacidades de disparo dual.
An analysis of the Nexus Switch’s structure reveals a solution characterized by «separation and decoupling.» The stem is made of POM and contains a Neodymium-Iron-Boron (NdFeB) permanent magnet to generate the field required for the Hall effect sensor. Meanwhile, the contact leaf assembly (comprising a moving copper alloy leaf and a stationary leaf) is housed in a separate zone on the side of the stem, handling mechanical actuation and bottom-out feedback. These two systems are physically separated; the contact leaf’s movement path avoids the magnet’s effective field zone, and the magnet’s field does not extend to the contact points of the leaf.
Crucially, the functions are decoupled. The contact leaf is responsible solely for «tactile feel» and «mechanical conduction,» while the magnet handles «magnetic sensing actuation.» In magnetic switch mode, the contact leaf plays no role in signal generation; in mechanical switch mode, the magnet does not participate in trigger detection. Each system operates independently, eliminating logical conflicts—such as the need for arbitration between simultaneous contact-based and magnetic signals.
IV. Lógica operacional del sistema de modo dual
It is important to clarify a common misconception: the «dual-mode» capability does not mean the switch itself automatically toggles between modes. Instead, the operating path is determined by the PCB on which the switch is installed. When mounted on a standard mechanical keyboard, it functions as a mechanical switch (using contact leaf conduction); when mounted on a standard magnetic keyboard, it theoretically utilizes the Hall effect path (though pin compatibility issues may arise). What truly enables the simultaneous availability of both systems is the dedicated PCB found in the Lofree HYZEN. The HYZEN board supports both mechanical and magnetic switch architectures, allowing for board-wide mode switching via a physical toggle on the keyboard. When switched to the mechanical mode, the system relies on metal leaf contact, with a fixed actuation point of 1.3mm; when switched to the magnetic mode, it utilizes Hall-effect sensing, allowing the actuation point to be customized between 0.01mm and 3.5mm via software, while also supporting features like Rapid Trigger and DKS.
V. Compensaciones estructurales
The «physical isolation + functional decoupling» approach of the Nexus Switch solves interference issues but entails several unavoidable trade-offs.
PCB compatibility is the most immediate issue. Magnetic switch PCBs lack the pinholes required for mechanical switch leaf contacts; installing the Nexus Switch onto a magnetic switch keyboard necessitates trimming the leaf contact pins, which permanently disables the mechanical mode. Conversely, when installed on a standard mechanical keyboard, the lack of corresponding sensing circuitry for the magnet and Hall sensor renders the magnetic switch functions inoperable. In essence, the Nexus Switch is currently a «specialized switch» compatible only with the HYZEN keyboard.
Old issues associated with mechanical modes have resurfaced. Metal contacts bring about problems such as contact bounce, the need for debouncing strategies, and long-term oxidation—issues that have plagued mechanical switches for decades. While the era of pure magnetic switches had shed this «baggage,» the Nexus Switch reintroduced it to achieve a specific typing feel. Some early HYZEN users reported double-clicking issues in mechanical mode, a problem rooted in the physical contact characteristics of the metal leaf.
Challenges in acoustic tuning. The coexistence of the metal leaf and the magnet encroaches upon the internal acoustic space of the switch. Some reviews describe the Nexus Switch’s sound as a «muffled, Hi-Fi ‘mahjong tile’ sound»—a positive attribute derived from the metal leaf—while others criticize the sound quality, indicating inconsistencies in acoustics across different production batches or keyboard structures.
VI. Especificaciones
El Nexus Switch está disponible actualmente en una sola especificación:
Fuerza de operación: 40 ± 10 gf
Recorrido de accionamiento: 1.3 ± 0.4 mm (ajustable en modo de interruptor magnético; fijo en modo de interruptor mecánico)
Recorrido total: 3.5 ± 0.2 mm
Flujo magnético inicial: 90 ± 15 Gs
Flujo magnético inferior hacia afuera: 480 ± 40 Gs
Vida útil mecánica: 80 millones de ciclos; admite intercambio en caliente (no soldable); temperatura de funcionamiento: -10°C a +70°C.
