A sensorless brushless motor drives commutation from the motor's own electrical signals instead of built-in Hall sensors — a control choice engineers specify to cut wiring, save space, or keep a sealed housing. SLW Motor builds sensorless BLDC units to custom torque, speed, and voltage targets for OEM programs moving from prototype through bulk production.
A sensorless brushless motor removes Hall-effect sensors entirely. The controller reads back-EMF — the voltage the spinning rotor induces in the unpowered winding — to infer rotor position and time each commutation step.
Both are BLDC motors; the difference is where rotor-position feedback comes from, and that decision carries real trade-offs.
Sensorless designs drop the sensor cable and PCB, cutting part count and connector points.
Fewer components lowers the per-unit parts cost in bulk runs.
No external sensor wiring to protect makes sensorless motors easier to seal against dust and moisture.
Sensored designs give the controller direct rotor-position data from a dead stop; sensorless (back-EMF) commutation can't read position until the rotor is already turning.
Removing the sensor board frees a small amount of axial length inside a tight envelope.
If you need guaranteed smooth starts from zero RPM, weigh the sensored vs sensorless trade-off on the Hall sensor brushless motor page against these savings, and see brushless vs other motor types for the wider picture.
Sensorless commutation is a control option we build into a BLDC motor around your spec — the sizes and voltages below are representative of the housings we work from before tuning torque, speed, and gearing to your load.
| Frame | Voltage Windings (applied range) | No-Load Speed | Torque & Output at Max Efficiency | Gearbox Option |
|---|---|---|---|---|
| 16mm 1636 coreless BLDC | 12V / 24V (3–24V) | 12,000 rpm | 32.6 g·cm rated at 10,000 rpm | Planetary 14:1–1621:1 |
| 22mm BLDC | 12V / 18V / 24V (6–24V) | 3,100–8,600 rpm | 270–380 g·cm, 10–27.5W, up to 75.3% efficiency | Planetary available |
| 24mm BLDC | 9V / 12V / 24V (6–48V) | 5,400–8,700 rpm | 48.6–67.2 g·cm, up to 4.84W | Gearbox 4:1–500:1 |
| 28mm BLDC | 7.4V / 12V / 24V (6–48V) | 4,800–11,800 rpm | 90–156.8 g·cm, 3.6–16.5W | Planetary 4:1–625:1 |
| 36mm BLDC | 12V / 18V / 24V (6–48V) | 5,200–7,500 rpm | 175–209 g·cm, 7.4–12W | Planetary 3.7:1–721:1 or worm |
| 42mm BLDC | 12V / 18V / 24V (6–48V) | Per winding | 10–27W | Planetary 3.7:1–721:1 |
| 60mm BLDC | 12V / 18V / 24V (6–48V) | Per winding | 10–27W, stall current 6.38–7.84A | Bare motor |
IP sealing, connector, and lead configuration are tuned to your housing requirement, so send your load, speed, and driver details before assuming a standard rating applies.
Torque, speed, voltage, and power output are configured to your application rather than sold off a fixed spec sheet.
Every build is tuned to the performance your application actually needs, not a stock datasheet.
Housing and gear components can use brass, stainless steel, powder-metallurgy alloys, or engineering plastics.
The material is chosen by load, environment, and cost target.
PCB soldering and wire harness assembly are available on request.
The sensor board itself is omitted by design in a sensorless build.
Flexible sample customization scales to stable bulk delivery, covering custom-engineered builds.
It also covers adaptations of the full BLDC motor range.
Where axial length or rotor inertia is the binding constraint, our coreless motor options can help.
These can be built with the same sensorless control approach.
Removing the sensor and its wiring matters most where every connector is a liability or every millimeter of housing counts: sealed medical device housings, automation modules, smart-device actuators, and compact robotics motor solutions.
Precision equipment builders weigh the same trade-off — sensorless when the motor runs mostly at speed, sensored when low-speed control matters more than part count.
SLW Motor operates from a 2,400 m² facility in Shenzhen with 56+ staff and 15+ years of motor and gearbox engineering experience, including work for Japanese manufacturing clients.
Every build passes through incoming inspection, in-process testing, and final verification to support consistent performance and dimensional accuracy, backed by ISO 9001:2015 certification and RoHS and Halogen-Free test documentation.
Send us your torque, speed, voltage, and housing requirements and we'll confirm whether a sensorless configuration fits before quoting. Flexible sample customization and prompt quotation feedback support everything from a first prototype to a stable bulk order.
To start your sensorless BLDC build, Contact SLW Motor with your application details.
A sensorless brushless motor commutates using back-EMF signals from the windings instead of Hall sensors.
Tell us your project or application requirements, and our team will get back to you with technical support, product recommendations, or a customized motor solution.
