A spindle actuator is the first choice when heavy windows, large flaps or skylights are to be opened electrically. It works with a threaded spindle, achieves high forces and long strokes and holds the window securely in any position. Here you will learn how a spindle actuator for windows works, where it is used and how to choose the right model.
In brief: A spindle actuator moves the sash via a threaded spindle and achieves high forces and long strokes. Because the thread is self-locking, the window stays in position even without power. It is suitable for heavy roof windows, large flaps and rooflights.
How a spindle actuator works
An electric motor turns a threaded spindle via a gearbox. A nut runs on the spindle and is connected to the push rod. When the spindle turns, the push rod moves straight out or in and pushes the window open or pulls it closed. Because the thread is self-locking, the window stays in its position without power. Spindle actuators are often also called linear actuators because they produce a straight movement.
Where are spindle actuators used?
- Skylights and continuous rooflights on hall and flat roofs
- Heavy skylights and glass roofs
- Large bottom-hung, top-hung and pivot sashes in facades
- Ventilation flaps in industry and commerce
- Smoke and heat exhaust ventilation systems, if actuator, window and control panel are matched for the specific project
Spindle actuator or chain actuator?
| Criterion | Spindle drive | Chain drive |
|---|---|---|
| Force | high, up to 5,000 N | usually 250 to 1,000 N, strong models up to 2,500 N |
| Stroke | long, up to 1,000 mm | shorter, depending on chain length |
| Design | Actuator with push rod, needs space next to the sash | compact, almost disappears in the frame |
| Typical use | Skylights, heavy roof windows, large flaps | Facade windows, top-hung windows, light roof windows |
You will find the detailed comparison in the guide Chain drive, linear drive or rack and pinion drive. For visibly mounted, robust actuators, read the guide Rack-and-pinion actuator for windows.
Choosing the right spindle actuator
1. Determine the force
The required push and pull force depends on the sash weight, the installation position and the distance of the actuator from the pivot point. Plan a reserve for wind and snow. The guide shows how to estimate the force Calculate thrust.
2. Define the stroke
The stroke determines how far the window opens. It depends on the desired Opening width and the geometry of the sash. Too long a stroke can over-push the sash, too short a stroke does not open far enough.
3. Choose the voltage
24 V actuators are usually used for ventilation with sensors and for SHEV. Advice on the choice is given in the guide Window actuator 24 V or 230 V.
4. Check the installation
A spindle actuator is fixed to the frame and the sash with brackets and swivels as it opens. Check whether there is enough space next to the sash and whether the brackets can be fixed securely, see Bracket and Mounting position.
Spindle actuators from Vent Systems
- VS-LA linear actuator: 600 N to 5,000 N, stroke 100 to 800 mm, standard bracket set included in the price.
- VS-SA 2500 spindle drive: 2,500 N, stroke 100 to 1,000 mm, specially for heavy skylights.
- VS-LA-i smart linear actuator: 800 N to 5,000 N, with synchronisation function and bus integration.
All models are available from stock in Hamburg. You can find the overview in the category Spindle drives.
Frequently asked questions
Is a spindle actuator the same as a linear actuator?
In the window sector the terms are usually used interchangeably. Both produce a straight stroke movement, the spindle actuator via a threaded spindle.
Can a spindle actuator replace an old actuator?
Often yes, if force, stroke, voltage and fixing match. The guide helps with the replacement Replacing a rooflight actuator.
Does a spindle actuator need maintenance?
Spindle actuators are low-maintenance. Regularly check brackets, screws and cables. In SHEV systems, the prescribed inspections also apply, see RWA maintenance and inspection obligations.
Consultation
Send us dimensions, weight and a photo of your window or skylight via the Contact form. We will recommend the right spindle actuator for you.