A steerable catheter includes a brake mechanism with a knob mounted to a catheter handle body. The knob is rotatable around a knob axis, and the catheter handle body includes at least one steering control spool rotatable around a spool axis that is orthogonal to the knob axis. The knob contacts and rotates in a limited arc along a recessed handle body surface between stop surfaces. A frictional braking element in mechanical communication, along the knob axis, with the knob is disposed adjacent the at least one steering control spool and actuatable into and out of contact with a contact surface of the at least one spool upon rotation of the knob around the knob axis.