A surgical instrument system , comprising: a housing interface comprising a motor; and a shaft attachment adapter ; a shaft assembly attachable to said shaft attachment adapter of said housing interface, wherein said shaft assembly is rotatable relative to said shaft attachment adapter, wherein said shaft assembly comprises: a shaft ; an end effector attached to said shaft; an actuation member positioned within said shaft; and an electrical attachment mechanism positioned on a proximal end of said shaft assembly, the electrical attachment mechanism comprising a plurality of electrical contacts and a plurality of electrical leads extending distally from said electrical contacts; an orientation detection system , comprising: a slip ring assembly configured to place said shaft assembly in electrical communication with said electrical attachment mechanism, said slip ring assembly comprising a plurality of slip rings each comprising an electrical discontinuity , said plurality of slip rings configured to be electrically coupled with said electrical contacts; wherein the orientation detection system is configured to determine the orientation of said shaft assembly relative to said housing interface using said electrical discontinuities; and a control circuit comprising a motor control program configured to run said motor, wherein said control circuit is configured to adjust said motor control program based on the determined orientation of said shaft assembly relative to said housing interface. a housing interface comprising a motor; and a shaft attachment adapter ; a motor; and a shaft attachment adapter ; a shaft assembly attachable to said shaft attachment adapter of said housing interface, wherein said shaft assembly is rotatable relative to said shaft attachment adapter, wherein said shaft assembly comprises: a shaft ; an end effector attached to said shaft; an actuation member positioned within said shaft; and an electrical attachment mechanism positioned on a proximal end of said shaft assembly, the electrical attachment mechanism comprising a plurality of electrical contacts and a plurality of electrical leads extending distally from said electrical contacts; a shaft ; an end effector attached to said shaft; an actuation member positioned within said shaft; and an electrical attachment mechanism positioned on a proximal end of said shaft assembly, the electrical attachment mechanism comprising a plurality of electrical contacts and a plurality of electrical leads extending distally from said electrical contacts; an orientation detection system , comprising: a slip ring assembly configured to place said shaft assembly in electrical communication with said electrical attachment mechanism, said slip ring assembly comprising a plurality of slip rings each comprising an electrical discontinuity , said plurality of slip rings configured to be electrically coupled with said electrical contacts; wherein the orientation detection system is configured to determine the orientation of said shaft assembly relative to said housing interface using said electrical discontinuities; and a control circuit comprising a motor control program configured to run said motor, wherein said control circuit is configured to adjust said motor control program based on the determined orientation of said shaft assembly relative to said housing interface. a slip ring assembly configured to place said shaft assembly in electrical communication with said electrical attachment mechanism, said slip ring assembly comprising a plurality of slip rings each comprising an electrical discontinuity , said plurality of slip rings configured to be electrically coupled with said electrical contacts; wherein the orientation detection system is configured to determine the orientation of said shaft assembly relative to said housing interface using said electrical discontinuities; and a control circuit comprising a motor control program configured to run said motor, <EOS>