I just wanted to know if there is a type of motor that will spin freely when turned off. Basically i am building a mechanism that will pull back a slingshot, and release it to launch a projectile.
If you have any recommendations i would really appreciate it.
Not the answer to your question but for what it's worth :-
For that sort of application you really need an instantaneous release of energy. "Unwinding" a motor will not give this as the motor inertia will effectively act as a brake, resulting in a slow release. I'd advise you look at a trigger mechanism to release the "elastic" once it's been wound up. The motor can then be run back to pick up and restretch the elastic.
jackrae - thanks for the suggestion. I was actually thinking that the motor may hold back from releasing the slingshot. I was just curious if there was a free spinning motor that had little to no resistance when not turned on, or possibly spin fast enough in the opposite direction to release the projectile.