Magnetic Linear Drive vs Gearless Sliding Door Operators: Choosing CF or QT

Choosing a sliding door operator starts with understanding how the drive moves the door—not simply comparing the largest load figure in a catalogue. For door manufacturers and installation businesses considering PTADOOR products, CF and QT represent different drive approaches. CF uses magnetic linear drive technology. QT uses a high-torque rotary motor without a reduction gearbox; the QT-K sliding door assembly includes a belt.

This distinction matters when matching an operator to a door profile, installation arrangement and supply scope. A gearless motor does not necessarily mean a beltless door system, and a magnetic drive does not eliminate the need for mechanical support and guidance.

What is the difference between CF and QT?

CF generates linear driving force through its magnetic drive arrangement. Buyers should consider how the selected motor, moving components and door structure fit together. The CF range contains different configurations, so selecting the technology is only the first step toward selecting a complete assembly.

QT uses rotary direct-drive technology without a reduction gearbox. In the QT-K assembly, a belt remains part of the door transmission. This makes it important to distinguish the motor design from the mechanism that transfers movement to the door leaf.

Neither family name is enough to establish suitability for a particular project. Request the drawing and specification for the actual assembly being quoted.

Start with the door arrangement

Before choosing an operator, define whether the project uses one moving leaf, two moving leaves or a more complex arrangement. Record each moving leaf's weight and dimensions separately. Include the frame and installed hardware when preparing the weight information.

A double-leaf rating should not be interpreted as the permitted weight of each leaf unless the specification explicitly says so. Likewise, a motor rating should not be treated as confirmation that every track, hanger and mounting configuration can support the same door.

For an existing door design, provide a profile section and describe the available mounting space. For a new product line, ask the supplier to review the proposed integration before finalising the profile around an assumed operator size.

Decide whether you need a motor or a door operator assembly

A door manufacturer developing its own system may need a drive component to integrate into an existing design. An installation business may instead need an assembly with a clearly defined set of supplied components.

These are different purchasing requirements. Ask the supplier to identify what is included in the quotation: motor, controller, track, transmission components, hangers, power supply, activation devices and any optional accessories. Do not assume that items shown together in a brochure are all included in the quoted package.

This is particularly relevant when comparing a CF motor proposal with a QT-K assembly. Compare equivalent supply scopes before drawing conclusions about price or installation work.

Compare the proposed configuration, not broad performance claims

The drive principle alone does not establish which complete door will be quieter, use less energy or require less maintenance. Those comparisons need evidence for the proposed configurations under comparable conditions.

If noise is a purchasing criterion, ask for the measurement conditions and the door configuration used. If energy consumption matters, distinguish motor rated power from measured consumption during an operating cycle. If maintenance is a concern, request the maintenance instructions for the supplied assembly rather than assuming that removing a gearbox removes every service requirement.

For a hospital or another specialised project, describe the specific door function. A general entrance and a dedicated airtight-door application should not be treated as interchangeable simply because both are located in a hospital.

Prepare a useful enquiry

To help PTADOOR review a CF or QT proposal, include:

• Your role: door manufacturer, distributor, installer or project integrator.
• The door arrangement, leaf dimensions and weight per moving leaf.
• A section drawing or photographs showing the mounting arrangement.
• Whether you need a motor component or a defined operator package.
• The intended application and operating environment.
• The required activation, access-control and other interfaces.
• The project destination and any documentation requirements.

You can explore the PTADOOR product range before preparing your enquiry. For a configuration review, contact PTADOOR with the door information above and ask for a model-specific proposal, drawing and confirmed supply scope.

Frequently asked questions

Does gearless mean beltless?

No. QT uses a motor without a reduction gearbox, while the QT-K sliding door assembly includes a belt. Always check the transmission arrangement of the complete assembly.

Does magnetic linear drive mean the entire door has no mechanical contact?

No. The drive principle should not be confused with the complete support and guidance arrangement. Review the selected door system's mechanical components and maintenance instructions.

Can I choose a model using door weight alone?

Weight is an important input, but it does not define the entire installation. The leaf arrangement, dimensions, mounting structure, supply scope and application also need to be reviewed before confirming a model.