A steering mechanism for a medical device that is configured for passing through the body cavities of a patient and for passage through an endoscope working channel is described. The mechanism comprises at least one spool having a central hole through which a central axle passes, the spool being rotatable about the axle, and the spool having at least one retaining tube having a lumen therethrough and configured to contain a portion of a drive cable. The drive cables, which may include UHMWPE, are capable of and are effective for deflecting the distal end of a catheter or endoscopic device, while preferably each being at least partially disposed through a retaining tube that is effective to prevent tangling or other binding of the cable(s).
