The present invention provides self-aligning rotational connectors. In an non-limiting embodiment, a catheter system comprises a catheter connectable to a drive unit. The catheter includes a rotator, and at least one orientating feature extending proximally from the rotator, and configured to be inserted into an orienting slot of a shaft connector of the drive unit. When the orienting feature is inserted into the slot of the shaft connector, the slot transmits torque from the shaft connector to the orientating feature, and therefore the rotator of the catheter. Electrical contacts are provided on the rotator and the shaft connector, wherein the contacts of the rotator are properly aligned with and engage the contacts of the shaft connector. Further, the shaft connector has a slopping surface that slops downward into the slot for automatically aligning the rotator rotationally with the shaft connector during insertion of the catheter into the drive unit.