Surgical assemblies and related methods are disclosed that provide for decoupling of instrument shaft roll and end effector actuation. A surgical assembly comprises: an actuation assembly including a main shaft motor, a main shaft encoder, a first motor, and a first encoder； a rotatable main shaft rotationally mounted to the actuation assembly and extending between a distal end and a proximal end, the rotatable main shaft being drivingly coupled to the main shaft motor, the main shaft encoder configured to measure an angular orientation of the rotatable main shaft. The assembly further comprises an end effector supported at the distal end of the rotatable main shaft and including a first actuation mechanism driven by a first rotational motion； a first drive shaft rotationally coupled with the first actuation mechanism and configured to provide the first rotational motion to the first actuation mechanism, the first drive shaft being drivingly coupled to the first motor, the first encoder configured to measure an angular orientation of the first drive shaft. The assembly comprises as well a controller including at least one processor and a storage subsystem storing instructions executable by the at least one processor to cause the at least one processor to: monitor orientation of the rotatable main shaft via the main shaft encoder； monitor orientation of the first drive shaft via the first encoder； and control operation of the first motor and the main shaft motor to simultaneously (a) rotate the rotatable main shaft relative to the actuation assembly, and rotate the first drive shaft to control articulation of the first actuation mechanism independent of the rotation of the rotatable main shaft relative to the actuation assembly.
