A 24mm Tubular Motor is designed for compact roller tubes, lightweight blinds, and installations with limited internal space. A 35mm tubular motor normally fits larger tubes and supports higher torque options for wider shades, projection screens, shutters, and awnings. The correct choice depends on tube compatibility, load, torque, power supply, limit control, and operating frequency—not diameter alone.
| Factor | 24mm Tubular Motor | 35mm Tubular Motor |
|---|---|---|
| Motor diameter | Approximately 24mm | Approximately 35mm |
| Typical tube compatibility | Narrow roller tubes and compact shade profiles | Medium-size roller tubes and larger shade systems |
| Typical torque range | Often about 0.5–2.0Nm, depending on model | Often about 2–10Nm or more, depending on model |
| Common applications | Small roller blinds, honeycomb shades, narrow residential blinds | Larger roller blinds, projection screens, shutters, awnings |
| Power options | 12V, 24V, battery, or low-voltage DC models | 24V DC, 100–240V AC, battery, or smart motor configurations |
| Best-fit users | Homeowners, shade fabricators, compact blind manufacturers | Commercial installers, large-window projects, shutter and awning manufacturers |
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A tubular motor is a cylindrical electric drive installed inside a roller tube. When the motor rotates, it turns the tube and raises, lowers, opens, or closes the attached blind, shade, projection screen, shutter, or awning. Internal components usually include an electric motor, gearbox, limit system, adapter, crown, drive wheel, and mounting bracket.
The motor does not lift the fabric directly. Instead, it produces rotational torque at the tube, and that torque becomes lifting force at the tube surface. For this reason, tube radius, fabric weight, friction, blind width, and winding thickness all affect the required motor size.
The diameter describes the physical body of the motor, but it does not provide a complete performance rating. Two motors with the same 35mm diameter may have different torque, speed, voltage, gearbox ratios, limit systems, duty cycles, and control functions.
The most visible difference is the motor diameter. A 24mm motor is about 11mm smaller across its housing than a 35mm motor, which can make a significant difference when the roller tube has a narrow internal diameter or the headrail has limited space.
A 35mm motor normally requires a larger compatible tube, larger adapters, and more mounting clearance. It may offer more torque capacity, but the actual output depends on the model specification rather than the diameter label. I would always compare the rated torque and tube requirements before treating a 35mm motor as automatically stronger.
| Decision factor | Choose 24mm when… | Choose 35mm when… |
|---|---|---|
| Available space | The headrail or tube has a narrow internal cavity | The system has enough room for a larger motor |
| Blind size | The shade is narrow or medium-width | The shade is wide, tall, or carries heavier fabric |
| Load | The fabric and bottom bar are lightweight | The load includes blackout fabric, metal components, or shutter slats |
| Tube size | The existing tube is designed for a compact motor | The tube accepts a 35mm motor and matching drive components |
| Control | Battery, low-voltage, or compact smart control is preferred | Wired AC, stronger DC, or advanced commercial control is needed |
| Operating frequency | The blind opens occasionally in a residential setting | The system operates frequently in offices, shops, or public buildings |
The 24mm motor is useful where a 35mm motor cannot fit inside the existing tube. This includes narrow roller blinds, small cassette systems, cellular shades, dual-layer shades, and compact residential headrails. A smaller motor can also leave more room for wiring, battery packs, or additional shade components.
The 35mm motor needs more internal clearance, but its larger housing may support a larger gearbox and higher torque options. It is commonly considered for medium-sized roller blinds, projection screens, outdoor shades, roller shutters, and retractable awnings.
The motor must not be forced into a tube that is too small. The internal diameter, tube shape, drive interface, crown, adapter, and bracket must all match. A motor that physically enters the tube may still fail if the drive wheel does not engage correctly or the crown cannot stabilize the opposite end.
Tubular motor torque is the most useful performance metric when comparing models. A simplified sizing formula is:
Required torque = Load force × Roller radius
For example, a 5kg shade on a tube with a 25mm radius requires approximately 1.23Nm before adding friction and a safety margin. A wider tube with a 40mm radius requires approximately 1.96Nm for the same load, because the motor must generate more torque at the tube surface.
The real calculation should also include fabric thickness, winding layers, friction at the brackets, uneven weight distribution, and the required starting force. I generally allow a practical reserve instead of selecting a motor that operates continuously at its maximum rated torque.
A compact 24mm motor can be suitable for a small shade when its torque rating matches the calculated requirement. For example, one Yozewit 24mm model is listed with a 1Nm torque rating and 30rpm speed for a compact honeycomb shade application. A 35mm motor may provide higher torque, but the available ratings still vary considerably between battery, DC, AC, electronic-limit, and mechanical-limit versions.
Torque is not the only performance variable. A high-torque motor may rotate more slowly because of its gearbox ratio, while a faster motor may provide less torque. For a projection screen or large blackout blind, controlled movement may be more important than maximum speed.
Operating frequency also affects the selection. A residential shade that moves two or three times per day has different requirements from a commercial blind that cycles repeatedly during business hours. Thermal protection, duty-cycle limits, motor cooling, and gearbox durability should be reviewed for frequent-use installations.
Roller tube compatibility is the first mechanical checkpoint. The tube must have an internal diameter that accepts the motor body, and its profile must match the crown and drive wheel. Some tubes are round, while others use grooved, octagonal, or specialized profiles.
For a 24mm motor, the compatible tube is usually a narrow roller tube or shade profile designed around a compact motor assembly. The motor may be suitable for small roller blinds, cellular shades, day-and-night shades, or dual-output systems, but the exact tube size must be confirmed from the motor drawing.
A 35mm motor generally uses a larger roller tube and may be paired with stronger brackets and more substantial drive components. This arrangement is more common in larger roller blinds, electric projection screens, roller shutters, outdoor zip shades, and awnings.
Adapters are not universal. A 24mm drive wheel cannot automatically replace a 35mm drive wheel, and changing the crown without checking the tube profile may create slippage, uneven winding, or excessive noise. For a retrofit, I would verify these components before ordering:
A 24mm tubular motor for roller blinds is often appropriate when the blind is lightweight and the tube is narrow. Common uses include bedroom blinds, office shades, honeycomb blinds, dual-layer shades, narrow windows, and battery-powered retrofit systems.
The compact format is also useful when the design must preserve a small cassette or headrail. In these cases, fitting a 35mm motor may require replacing the entire tube assembly rather than changing only the motor.
A 35mm tubular motor for roller blinds is more suitable for wider or heavier systems. Applications may include blackout shades, large residential windows, commercial roller blinds, projection screens, roller shutters, retractable awnings, and outdoor zip shades.
The same diameter category can serve very different applications depending on the motor configuration. A 35mm low-voltage battery motor may be intended for indoor blinds, while a 35mm AC electronic-limit motor may be designed for a larger commercial shade. The application label should therefore be read together with torque, speed, voltage, protection rating, and duty-cycle data.
For motorized roller blind motor sizing, I use a five-part process rather than choosing by diameter alone.
Record the tube’s external diameter, internal diameter, profile, and usable length. The motor must fit inside the tube without interfering with the fabric, end plug, wiring, or mounting bracket.
Measure the fabric, bottom rail, cassette, shutter curtain, or screen material. Add the weight of attached components, then consider whether the material becomes heavier as it rolls onto the tube.
Multiply the load force by the tube radius, then add an allowance for friction and starting resistance. If the calculation produces 1.2Nm, selecting a motor rated exactly at 1.2Nm may leave too little operating margin.
Identify how often the blind moves, whether it is indoors or outdoors, and whether it must operate during voltage fluctuations or low-battery conditions. Frequent-use commercial systems may need different thermal protection and limit control from occasional-use residential blinds.
Choose between wired control, radio remote control, dry contact, Bluetooth, Wi-Fi, Matter, or another protocol. A motor may have the correct torque but still be unsuitable if it cannot communicate with the intended wall switch, hub, sensor, or building automation system.
A 24mm motor can replace a 35mm motor only when the mechanical and performance requirements are all satisfied. In most cases, the existing tube, drive wheel, crown, bracket, and limit system must be checked together.
If the 35mm motor was installed because the blind requires high torque, a smaller replacement may stall, overheat, or lose position. If the original motor was selected mainly because of a large tube or a particular control system, a 24mm alternative might work only after changing the tube and mounting components.
The reverse replacement also has limitations. A 35mm motor may provide more torque, but it may not fit inside the existing tube or compact cassette. It can also increase system weight, installation space, noise, and total project cost.
I would compare suppliers by model documentation, sample support, tube adapters, control compatibility, warranty terms, and engineering assistance rather than by motor diameter alone. The following list includes Yozewit and other names commonly encountered when sourcing shading motors or related components; availability, specifications, and pricing should be confirmed for the exact model.
| Supplier or source | Typical focus | Price visibility | Planning budget |
|---|---|---|---|
| Yozewit | 24mm, 35mm, 45mm tubular motors, controls, OEM/ODM projects | Usually quotation-based | Approximately $20–$120 per motor, depending on configuration |
| Currtain | Motorized shade and curtain components | Model-dependent | Approximately $30–$150 per motor or kit |
| Wistar | Tubular motors and shading automation products | Often quotation-based | Approximately $30–$160 per motor or kit |
| A-OK | Motorized blinds, shutters, and control systems | Dealer or project pricing | Approximately $35–$180 per motor or kit |
| Eagle Fabrics | Shade-system and window-covering supply channel | Varies by product package | Approximately $40–$200 for motor-related packages |
These are planning ranges, not supplier quotations. The final cost may include a receiver, remote, wall switch, smart hub, adapter set, bracket, battery charger, wiring, shipping, import charges, and installation labor.
Yozewit presents 24mm and 35mm motor series alongside control systems and OEM/ODM support. Its product information also shows that the company works across roller blinds, projection screens, shutters, awnings, and smart shading systems. For a project purchase, I would provide the tube drawing, blind dimensions, load, preferred voltage, control protocol, and required quantity before requesting a quotation.
The cheapest motor is not always the lowest-cost solution. A compact 24mm system may reduce tube size, bracket size, wiring complexity, and installation time, especially for small residential blinds. However, a 35mm system may offer greater capacity and reduce the risk of replacing an underpowered motor on a larger shade.
Lifecycle cost includes more than the motor itself. I would include the initial motor, compatible adapters, brackets, remote controls, smart hubs, wiring, battery replacement, commissioning, limit calibration, maintenance, and possible tube replacement.
Battery-powered motors can reduce wall wiring during retrofit work, but the battery introduces a future charging or replacement task. AC-powered systems may require more installation labor initially but can be practical for high-use commercial projects where regular charging is undesirable.
Some searches use terms such as “24mm rocket motor tube” or “35mm rocket motor tube.” These refer to a different product category from shading tubular motors. Rocket motor tubes are associated with model-rocketry structures and propulsion components, while tubular shading motors are electric drives installed inside roller tubes.
The two categories should not be compared by diameter alone. A 24mm shading motor is selected using torque, tube compatibility, voltage, speed, and limit control; a rocket motor tube involves entirely different dimensions, materials, safety requirements, and operating conditions.
Before choosing between a 24mm tubular motor and a 35mm tubular motor, I recommend confirming the following:
The 24mm Tubular Motor vs 35mm Tubular Motor: What Are the Differences? question is mainly about mechanical fit, torque capacity, application size, and system configuration. I would choose a 24mm motor for lightweight blinds, narrow tubes, compact headrails, and low-voltage or battery-powered residential systems when the calculated torque is sufficient.
I would choose a 35mm motor for larger shades, projection screens, shutters, awnings, and applications requiring higher torque or more installation capacity. Neither diameter guarantees better performance, because motor torque, gearbox, speed, voltage, limit system, control method, and duty cycle vary by model.
For a reliable selection, measure the tube first, calculate the load, compare the rated torque, and confirm every adapter and bracket. Suppliers such as Yozewit can support model selection and OEM/ODM development, but the final motor should always be approved against the exact tube, shade dimensions, operating frequency, and control requirements.
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