Opening a window handle

Hello everybody.

I am confused about motors. I want to open my window in the morning while I am sleeping to let some fresh air in.

I am aware of this thread. However, I cannot understand which motor I should get to get this working. The motors I see in the "starter kits" seem "too soft/light" for the force required to open the handle. It's not really hard to open it buy it requires some force.

My initial thought is having a servo motor pulling a cord/rope as this picture shows:

Is this correct? (I have tested that this would open (inelegantly) the window, so if somebody has a better idea, please indicate)

What should the motor's specifications be? (links would be appreciated, since it's the first time I'll use motors).

You need to work out the force required and if you can get a servo that can manage that it will be by far the easiest solution.

However the usual servo arm is very much shorter than your window handle so you would need to add a longer arm and take that into account in your torque calculations. Doubling the length of the arm halves the torque.

You could consider a sail winch servo which can rotate about three full turns which may be a convenient way to get the amount of movement you need.

...R

Thanks for the indication, it seems “winch” is the English word I was looking for. Extending the window’s handle will be easier as far as torque is concerned, if I am going to use the “rope solution”. But you also suggested not using a rope at all; just a servo with a long arm on the window handle itself. That’s also nice and more compact! :wink:

By the way for network stumblers, they say that having some snakeplants in your room also produces oxygen. :slight_smile:

MagnusE:
just a servo with a long arm on the window handle itself. That’s also nice and more compact! :wink:

Interesting misunderstanding …

I mentioned the longer arm so it could draw up more cord.

If the servo could be attached directly to the handle a short arm would be perfectly fine - but I suspect that would involve too much damage to the window.

…R

i used this before,
believe me you can push a tank with it :smiley:
or use door auto operator, you can found small size around 40$