Use this comparison to decide whether your roller shade program should start with compact 25mm motors, stronger 35mm motors or 45mm tubular motors with more reserve.
What This Page Helps You Decide
Motor diameter is one of the first visible decisions in a roller shade RFQ, but it should not be treated as a simple bigger-is-better choice. Diameter affects torque range, tube compatibility, minimum shade width, power type, motor head clearance and the accessory kit.
A clean OEM program often uses more than one diameter. A compact battery shade may use WM25BR, an AC smart shade may use WM25AW, wider blinds may move to YYGL35S or YYGL35R, and heavier commercial shading may require 45mm models such as YYGL45S or YYGL45R.
Fast procurement note
Use this page before asking for final price. A complete roller shade motor RFQ should connect application, size, tube, power, control, accessories and target market so Walter Motor can recommend a practical configuration.
How to Make the First Selection
This table gives a first-pass decision path. Final model selection should be confirmed with drawings, samples and the exact Walter motor configuration.
| Buyer Situation | Recommended Direction | Procurement Note |
|---|---|---|
| 25mm motor | Compact indoor roller shades, retrofit shades and smaller tube systems. | Check minimum width, tube ID, torque and battery or AC configuration. |
| 35mm motor | Larger roller blinds, light shading systems and programs needing more reserve than 25mm. | Review YYGL35S for wired mechanical limit or YYGL35R for built-in RF receiver needs. |
| 45mm motor | Heavier blinds, selected commercial shades and projects needing more torque reserve. | Confirm tube, fascia, headbox and bracket clearance before using a 45mm motor for blinds. |
| Mixed range | OEM buyers with many shade sizes or several markets. | Define rules for when the product family moves from 25mm to 35mm or 45mm. |
What Buyers, Engineers and Fabricators Should Check
25mm motors: compact shade systems
A 25mm motor is usually the first option for compact indoor roller shades because it can fit smaller tubes and tighter brackets. Walter's current product pages reference WM25BR as a 25mm rechargeable battery motor for indoor roller blinds and small shades, with 1.1Nm torque, 28rpm speed, Type-C charging and optional solar panel charging.
WM25AW is also a 25mm roller blinds motor, positioned for medium blinds and smart shading systems. The current page describes 1.1Nm torque, AC 100-240V input, electronic limit control, built-in RF 433.92 MHz control and optional WiFi or Zigbee connectivity.
The main limitation is reserve. A 25mm motor should not be pushed into large or heavy blinds only because the buyer wants one compact SKU. Minimum width is also critical because the motor body, head, brackets and charging access all consume space.
35mm motors: larger blinds and stronger indoor systems
A 35mm motor is often the next step when compact motors do not provide enough torque margin or when the shade system uses a larger tube. Walter's current pages position YYGL35S as a 35mm mechanical limit motor for roller blinds and light shutters, controlled by wall switch or matched external receiver.
YYGL35R adds a built-in receiver for RF remote control while keeping mechanical limit setting. This can reduce the need for a separate receiver box in remote-controlled blind programs, but pairing, channel planning and remote compatibility should be confirmed before order.
Do not move to 35mm only because it feels safer. A 35mm motor needs a larger compatible tube and may increase the minimum width of finished shades. It is a good option when the product design can accept those tradeoffs.
45mm motors: reserve for heavier shading systems
A 45mm tubular motor gives more torque reserve and can support heavier shading systems when the tube and installation space allow it. Walter's YYGL45S page confirms a 45mm AC mechanical limit motor with 10-50Nm torque range, 230V/50Hz standard, optional 110V/60Hz, IP44 protection and wall switch or external receiver control.
YYGL45R is the 45mm mechanical limit model with built-in receiver for RF remote control. It is more common in roller shutters, awnings, zip screens and heavier shading projects than in narrow indoor blinds.
For roller blinds, the 45mm decision should be intentional. The buyer should confirm tube inner diameter, headbox depth, bracket clearance, noise expectation and whether the added reserve is truly needed.
Motor Diameter Decision Matrix
Diameter should be selected by fit, torque reserve, power type and product range strategy. This matrix helps purchasing and engineering agree on when to move from 25mm to 35mm or 45mm models.
| Decision factor | 25mm direction | 35mm direction | 45mm direction |
|---|---|---|---|
| Typical program | Compact indoor roller shades and retrofit battery shades. | Larger roller blinds or light shading systems needing more reserve. | Heavier blinds or commercial systems with larger tube space. |
| Walter references | WM25BR battery; WM25AW AC smart roller blinds motor. | YYGL35S switch or receiver; YYGL35R built-in RF receiver. | YYGL45S switch or receiver; YYGL45R built-in RF receiver. |
| Main fit gate | Minimum width, charging access and tube ID. | Tube ID, bracket size and receiver strategy. | Tube ID, headbox depth, bracket strength and project need. |
| Procurement risk | Undersizing or poor runtime if used on large shades. | Unnecessary cost if the 25mm option already has enough reserve. | Oversizing, noise, space conflict and price if used as a default. |
| Best approval method | Test the smallest width and largest planned load. | Test the widest common shade with final tube and bracket. | Test the actual commercial assembly and site control plan. |
Avoid These Before Sample Approval
- Choosing 45mm only because it has more torque.
- Ignoring the tube ID and motor head when comparing diameters.
- Forgetting minimum bracket-to-bracket width.
- Mixing battery and AC assumptions in one diameter decision.
- Asking suppliers to quote a diameter before the shade size range is clear.
Recommended Procurement Path
Use 25mm for compact indoor and retrofit programs, 35mm for larger roller blinds and light shading systems, and 45mm only where the load, tube and installation space justify it. Ask Walter to review the shade range and define clear model transition rules before sample approval.
Data to Send Before Quotation
Copy these points into your inquiry so the motor, control method and accessory set can be checked together.
- Target shade size range and the largest blind in the program.
- Tube ID and OD for each product family.
- Minimum finished shade width requirement.
- Power type: rechargeable battery, solar assist, AC or DC.
- Control requirement: switch, RF, built-in receiver, gateway or protocol.
- Preferred Walter model references: WM25BR, WM25AW, YYGL35S, YYGL35R, YYGL45S or YYGL45R.
Continue the Buying Path
Frequently Asked Questions
When should I use a 25mm roller shade motor?
Use 25mm when the blind is compact, the tube ID fits, torque reserve is enough and minimum width is acceptable. WM25BR and WM25AW are current Walter references for 25mm shade motors.
When should I move from 25mm to 35mm?
Move to 35mm when the blind is wider, heavier or needs more reserve than a compact motor can provide, and when the tube and bracket system can accept the larger diameter.
Is 45mm too large for roller blinds?
It can be too large for compact indoor shades, but it may be appropriate for heavier blinds, commercial shades or projects that use larger tubes and need more torque reserve.
What is the risk of oversizing the motor?
Oversizing can increase cost, noise, minimum width, tube size and accessory complexity. It can also make a battery shade less attractive if runtime expectations are affected.
Can one motor diameter cover every shade size?
Sometimes one diameter can cover a narrow size range, but broad OEM programs often need diameter rules so small, medium and heavy shades use different configurations.
Send your roller blind motor data to Walter Motor
Include shade size, fabric weight, tube details, power preference, control method, accessories, target market and quantity. Walter can help check model selection before sample or batch order.