Can somebody recommend (stepper) motor. With this motor should have lifted off about 5 kg on 4m.
Stepper motors are rated by torque and power. If you want help to determine those factors, post the details of the lift mechanism, and state the total time in seconds required to lift the weight by 4 m.
No problem finding a motor. You just need to do the math finding out the torque needed.
When You know the motor You know the current needed from the driver, and the current supplied to it.
Insufficient information I'm afraid - what are you trying to actually achieve? What drive mechanism might be involved (winch?, belt?, leadscrew? something else?)
You need to calculate the torque needed at the motor shaft and what motor type is needed. Speed is also very important. Several have asked for more information, help us to help you!
Thanks for your answers....
I want to fasten the motor to the window structure.
The rope will be wound on a pulley (a roller) so I will run down and up with jalousie.
For the future I would like control jalousie using light sensor......
And can you write me where I can calculate the torque needed at the motor shaft?
If the max force on the rope is 50N, simply apply the torque equation using the radius of the drum.
Steppers are not a great choice for traction like this - a simple DC motor and limit switched are usually used (far less power needed). Also for this application you may
want to consider using a gearing system that can't be back-driven.