A deflection mechanism for an elongate medical device may comprise an actuator. The actuator may comprise a rotatable body comprising a channel, the channel comprising a plurality of recesses. The deflection mechanism may further comprises an activation wire having a proximal end and a distal end, and a wire lock attached to the proximal end of the activation wire. The wire lock may be disposed within the channel and configured to ride therein when the actuator body is rotated. An adjustable stop may be placed in one or more of the recesses of the channel so as to apply a force to the wire lock as the actuator is rotated so as to increase tension on the activation wire.