Mechanisms, assemblies, systems, tools, and methods include an offset drive shaft within an independently rotating member. An example method of transmitting torque through an offset drive shaft routed within a rotatable main shaft includes supporting a main shaft to rotate relative to a base so that the main shaft rotates about a main shaft rotational axis. A drive shaft is supported to rotate relative to the main shaft so that the drive shaft rotates about a drive shaft rotational axis that is offset from the main shaft rotational axis. The drive shaft is engaged with a drive feature having a drive feature rotational axis that is fixed relative to the base as the main shaft rotates. The main shaft is rotated relative to the base. The drive feature is rotated relative to the main shaft so as to rotate the drive shaft relative to the main shaft.