Thanks Robin for your answer.
I'm sorry. I was not clear. I need is to pull 2kg to 10kg object. I cannot really calculate the friction, but the specs of the mg955 are fine: Stall torque: 8.5 kgf·cm (on 4.8 V power source)
Otherwise i'm happy for the servo, but in my case, the servo can only go 180 degrees. And when not powered, it's really hard to "pull back" the object which is attached to the servo. (since the servo is kind of locked when not powered).
I was wondering if there are better ways to "pull stuff" than with a normal servo like mg955.
Are there any good "small winches" or motors that could just "pull with high torque" and being powered with batteries?
All ideas are welcome.
So basically. I have a object X which i need to pull with a rope. What kind of motor would pull the rope the best?
(Speed is not an issue here.)