Robotic surgical tool with replaceable carriage

A method of assembling a surgical tool, comprising:

• providing a handle having a first end, a second end, a lead screw and at least one spline extendable between the first and second ends, and an elevator layer movably mounted to the lead screw at a carriage nut;
• inserting the at least one spline through a drive gear housed in at least one additional layer and thereby operatively coupling the drive gear and the at least one spline such that the drive gear is rotatable with the at least one spline;
• and
• removably coupling the at least one additional layer to the elevator layer to define a carriage, wherein an elongate shaft extends distally from the one or more additional layers and an end effector is arranged at a distal end of the elongate shaft, and wherein an activating mechanism is housed in the at least one additional layer and operatively coupled to the drive gear such that rotation of the drive gear correspondingly actuates the activating mechanism.

A method of assembling a surgical tool, comprising:

• removing an end cap from a stage portion of the surgical tool, the stage portion including:
• a handle having a first end and a second end;
• a lead screw and at least one spline extendable between the first and second ends;
• and
• an elevator layer of a carriage movably mounted to the lead screw and the at least one spline;
• and
• advancing the carriage to the second end and detaching a first instrument portion from the stage portion, the first instrument portion including:
• one or more first additional layers removably coupled to the elevator layer;
• a first elongate shaft extending distally from the one or more first additional layers and having a first end effector arranged at a distal end of the first shaft;
• and
• replacing the first instrument portion with a second instrument portion coupled to the stage portion, the second instrument portion including:
• one or more second additional layers removably coupleable to the elevator layer;
• a second elongate shaft extending distally from the one or more second additional layers and having a second end effector arranged at a distal end of the second shaft.