I presume you mean "brake" rather than "break" - there is a big difference.
yes you are right, my bad
With a DC motor the current determines the torque, so it sounds like you need a four-quadrant motor
controller with torque-control option.
Stepper motor is utterly unsuitable.
is it alright to force the motor turn the other way? isn't it harmful to the motor?
is there a better way to do it?
Some people try to complicate something beyond all comprehension.
Go to your local hardware store and look at their selection of coil springs. Pick one that has the length of movement and the strength you need and use one for each line. OR if there are only two lines, Use one spring that is supported in the middle and attach a line to each end of the spring.
thank you for your insight, but it is not as simple as you think
after pulling the brake too much the wing stalls and break pressure drops to almost zero. after this point the reaction of the brake becomes totally different. releasing it back up the brake pressure is still soft. there is a lot more to this