A post I made yesterday suggesting winches.

Say you are trying to make a weighted catapult or trebuchet Perhaps even a ballista (without the torsion springs) And you need yo bring the arm down into a position with the most potential energy, IE the tip of the arm at the base and the weight well above. Springs can pull the arm down but iv found they are vastly too forceful and tend to rip everything apart as they are constantly accelerating up until the point they are no longer being activated.

I would like to suggest a winch/crank. Its a block that with connecting rope pulls the rope in then lets it free (while staying attached). It could be placed like the support struts or the springs where you click the first location (the winch block) then drag the rope to attach onto whatever you want winching. One button would wind it in and lock it in place meaning you could half winch a trebuchet and give less power and the other button would allow the rope from the winch to unwind.

Like a lot of the utility blocks it could have a winch speed drag bar, or a winch torque drag bar, even a slack rope length drag bar. It would allow for much smoother pulling back of heavy or big arms. Or it could be used as a way of making a ballista. Where one winch could pull a projectile back and two more could winch it in creating speed and a similar effect to the arms on a torsion spring driven ballista.