Hi, How would I go about finding the spring constant of a bundle of nylon rope acting as a torsion spring? I know the length. I dont know the width of the bundle. When twisted I wanted roughly 6cm diameter (is that a wrong method)? I ll be twisting it by 1080 degrees. When twisted as above ^ - how can I calculate how much force/energy it will project if an arm in the middle of the torsion spring is pulled against it by a certain length/angle. Im guessing that the longer the arm, the more it can pull back. Like a ballista. Thank you.