Buyers argue about torque more than about any other figure in motorised blinds, and they usually argue about the wrong part of it: the number itself rather than the tolerance behind it.
What torque actually controls in motorised blinds
Must be matched to blind width and weight; undersized motors stall.
It also explains why torque is the first line a buyer loosens and the last line a claim refers to.
For Motorised blinds, the working range is 1.2-3.0 Nm. Inside that band the choice is commercial; outside it, the product changes category and so does the price.
What 1.2-3.0 Nm does not tell you
| Position | Value | Effect on motorised blinds | Where it shows up |
|---|---|---|---|
| Floor | 1.2 | Lowest cost, least margin for process variation | Limit drift within a season |
| Working middle | 1.2-3.0 Nm | Predictable performance at a normal price | Nothing to negotiate, nothing to explain |
| Ceiling | 3.0 Nm | Best performance, highest cost | Cost the end product may not recover |
Specifying the ceiling is only justified when the end product carries a warranty that would be expensive to honour. Otherwise it is cost without a customer-visible benefit.
The figure that decides the outcome is not torque itself but the tolerance around it. A supplier who quotes 1.2-3.0 Nm without a tolerance has not quoted a specification, and the first lot will define the tolerance for you.
How to measure torque
The reference method here is Battery cycles, run to 300 cycles, with an acceptance of >= 80 % capacity retained. The method is the easy part; sampling and conditioning are where reports diverge.
Measure on the goods as delivered, not on the greige or the pre-finished material. The figure that matters is the one in the product your customer receives.
Record the measured value rather than pass or fail. A marginal pass on torque tells you the process is running at the edge, which is the information you need before the next lot rather than after it.
Torque does not stand alone
Torque moves with battery life (300-500 cycles per charge) and with limit setting (electronic with memory). Tightening one usually costs money in another, and a supplier who accepts every tolerance without comment has either not understood the interaction or is planning to substitute.
If a quotation is significantly cheaper, the difference is usually in one of these neighbours rather than in the figure being discussed.
The clause to write for torque
The line below is the version we can quote against without inventing anything. Torque appears with a tolerance and a test, not as a standalone number.
Motorised 50 mm basswood venetian blind, Li-ion battery, Zigbee 3.0, <= 32 dB, 2.0 Nm, electronic limits, manual override, 400 cycles per charge, EN 13120 safety
Write it once and reuse it. The buyers who avoid claims are not stricter than everyone else; they send the same well-written clause every time.
When torque goes wrong
Limit drift. The blind creeps past its top or bottom limit over months.
The cause is usually mechanical limit switches or unstable encoder counts.
The test that catches it: 1000-cycle endurance with position measurement every 100 cycles.
What to specify instead: Electronic limits with non-volatile memory, and re-calibration as a documented service step.
The pattern is consistent: the failure appears months after delivery, is hard to attribute, and the cost lands on the buyer. That is the argument for measuring torque on every lot rather than on the development sample.
Four questions about torque, before you order
- What tolerance do you hold on torque, and what did your last three lots measure against it?
- Which method do you use for battery cycles, and which laboratory signs the report?
- When torque falls outside 1.2-3.0 Nm, do you rework, downgrade, or ship and hope?
- Which of battery life or limit setting would you move first to hit a lower price?
The answers are more useful than a certificate, because they show whether the process is controlled or merely inspected. Full ranges for motorised blinds are on the product page, and the measurement regime is described on the quality control page.
Questions buyers ask before ordering
Can guests override it?
We supply a manual override and a lock-out mode for hotels. Specify both, because housekeeping will otherwise unplug the blind.
How many cycles will the battery really do?
300-500 on a 50 mm wooden blind, less on wide heavy blinds. We quote the tested figure and will send the cycle log; treat any figure above 600 with suspicion.
Three questions, and the answers that separate mills
If the motorised blinds figures on this page is going to be decided on a call, take these three questions into it.
| Question | Answer that should worry you | Answer that holds up |
|---|---|---|
| Which test catches motor stall on wide blinds? | “We have never had a complaint.” | Torque and current — on the production lot, with the acceptance figure written into the report and not into the email. |
| May I see a report for a lot you shipped last month? | “That is confidential customer information.” | A redacted report, which carries every number that matters and none of the customer’s identity. |
| Where in the Li-ion battery / 12 V DC / hardwired band will this order sit? | “In the middle, normally.” | A stated target and the readings behind it. Power drifting inside the band is how a conforming lot still fails. |
Failure modes, and the test that catches each one
A specification only earns its keep if it names the failure it prevents. These are the two that matter for the motorised blinds figures on this page.
| Failure | What triggers it | Test to demand on the production lot |
|---|---|---|
| Limit drift | Mechanical limit switches or unstable encoder counts. | Battery cycles — 300 cycles; acceptance >= 80 % capacity retained |
| Motor stall on wide blinds | Torque below what the blind weight and friction require. | Protocol conformance — certification test; acceptance pass for declared protocol |
The other two, with acceptance numbers attached, are in the full failure analysis for motorised blinds. A supplier who cannot name the mode he sees most often is describing a catalogue, not a process.
Need torque specified and tested against your end use?
Send a window schedule or a single set size and we will return a quotation with the loading plan, the safety standard that applies to your market and the lead time for the colour you need. Catalogue and current price list on request.
Related reading
- Battery life in Motorised blinds
- Motorised Blinds for Rental and hospitality
- Motorised Blinds vs Manual blinds with a wand
Catalogue and current price list · Neutral packing and private label · Consolidation, documents and lead times
