Magnetic Levitation Gap: 7 Critical Design Variables
A floating product can look stable while operating outside its intended geometry. magnetic levitation gap is the distance that links magnetic force, sensor range, payload, packaging, and visual composition. Treating it as a single headline number is a common cause of unstable prototypes and failed retail installations.
What Does the Magnetic Levitation Gap Measure?
The magnetic levitation gap is the controlled separation between the supported object or receiver and the base-side electromagnetic assembly. In a product design, it is not just empty space; it is the operating point at which the controller produces enough force and feedback authority for the declared payload.
The public Goodwell module page lists product-specific examples including 30–35 mm and 75–80 mm configurations, while the moocci development brief defines a 12–20 mm target range for selected modules. These values are not contradictory when they are assigned to different module and payload configurations.
The correct specification format therefore names the module, payload, center of gravity, unloaded gap, loaded gap, tolerance, and measurement method. If one of those fields is absent, the advertised number cannot be transferred safely into a new product.
| Variable | What changes | What the RFQ should state |
|---|---|---|
| Payload | Required force and control margin | Mass, dimensions, and load range |
| Center of gravity | Axial and radial moment | Position relative to the magnetic axis |
| Gap | Force curve and visual clearance | Nominal value and tolerance |
| Disturbance | Transient displacement | Touch, vibration, airflow, or rotation condition |
| Runtime | Thermal and drift behavior | Continuous operating duration |
Which 7 Variables Move the Usable Gap?
First, payload mass changes the force requirement. A module that maintains a specified unloaded distance may operate at a smaller loaded distance, or require a different control setting, once the object is installed.
Second, center of gravity and offset create a moment that the controller must correct. A flat product with a centered mass behaves differently from a shoe, bottle, watch, or sculpture whose mass sits away from the magnetic axis.
Third, the base and receiver geometry determine the coil, magnet, sensor, and mechanical clearance available. Fourth, the control loop determines how quickly the system corrects position error; the gap cannot be separated from feedback bandwidth and sensor resolution.
Fifth, external disturbance changes the transient gap. A buyer specifying a retail display should state whether visitors may touch the case, whether doors create airflow, and whether the object rotates or moves while levitated.
Sixth, thermal drift can change electrical resistance and actuator behavior during continuous operation. Seventh, the landing and restart mechanism defines the safe state when the gap collapses, power is interrupted, or the object is manually repositioned.
How Should a Buyer Test Gap Under Load?
Start with a calibrated measurement method and a fixed reference plane. Record the unloaded gap, then install the declared payload and measure the loaded position at the stated center of gravity. The report should include tolerance, not only a nominal photograph.
Run the test after the system reaches the intended operating temperature. If the product includes wireless induction powering, record the receiver alignment and output condition because coil coupling, heat, and mechanical position can interact with the levitation point.
For a commercial display, add a disturbance sequence: controlled touch, small airflow, repeated rotation if applicable, and a power interruption. The acceptance criteria should define maximum displacement, recovery time, landing behavior, and whether the product remains undamaged.
- Measure unloaded and loaded gap from the same datum
- State payload dimensions and center of gravity
- Record nominal gap and allowable tolerance
- Repeat after thermal stabilization
- Test disturbance and power-loss states
- Document the exact module and controller revision
- Keep the measurement record with the production approval file
How Does Goodwell Turn Gap Data into an OEM Brief?
Goodwell’s public material presents a range of magnetic levitation modules for different loads and gap configurations. The company brief also describes bottom-push levitation with closed-loop electromagnetic control, which is relevant because the control architecture must be tuned to the selected gap and payload rather than copied from a different product.
For developers, our FREE DESIGN workflow should capture the object’s dimensions, mass, center of gravity, visual height, rotation requirement, power input, wireless-power requirement, and failure state. That input lets the engineering team decide whether the requested gap is physically and commercially reasonable.
A useful reference point is the Goodwell Magnetic Levitation Module page, but a page-level range is not a substitute for a project datasheet. Ask for a configuration-specific record that matches your payload and enclosure.
Supplier Audit Checklist: 5 Documents to Request Before Signing
- Configuration datasheet: nominal gap, gap tolerance, load range, power input, and dimensions.
- Loaded-gap measurement report: measurement method, datum, payload, center of gravity, and temperature.
- Disturbance test record: touch, airflow, vibration, rotation, or other conditions relevant to the installation.
- Power-loss and landing test: safe-state behavior at the selected gap and declared payload.
- Prototype approval record: signed gap, load, appearance, and restart criteria before mass production.
FAQ: Specifying Magnetic Levitation Gap
Q: What is a magnetic levitation gap?
A magnetic levitation gap is the controlled distance between the levitated object or receiver and the supporting base or actuator. The usable value depends on the module, payload, center of gravity, control loop, and mechanical clearance.
Q: Is a larger levitation gap always better?
No. A larger gap can improve visual separation but usually changes the force, control range, packaging, and stability requirements. Compare gap together with load, offset, disturbance, and power rather than selecting the largest number.
Q: Why do different products use different gap values?
Products use different gaps because their payloads, geometry, magnets, coils, sensors, and visual requirements differ. Goodwell’s public module page lists several product-specific ranges, which is why the RFQ must name the exact configuration.
Q: What should a supplier include in a levitation-gap test?
The test should identify the measured gap, payload, center of gravity, load direction, power input, runtime, disturbance condition, and measurement method. A single unloaded photograph is not enough to validate a commercial specification.
If you are developing a floating light, retail display, speaker, globe, or custom object, send the payload drawing and center-of-gravity estimate to Goodwell Free Design. Email [email protected] with the requested gap, load, power, runtime, and failure-state requirements.
For the physics background behind induction, consult OpenStax’s electromagnetic induction reference. The engineering decision still depends on the configuration-specific gap and load test for the product you intend to build.
