The mechanical technology of converting oscillatory motion, into one direction of rotation, as described and claimed in U.S. Pat. No. 5,881,609, while being efficient, useful and having numerous applications, has its disadvantage of not being able to function unless user employs both hands; one hand to apply oscillatory motion to an input, while opposite hand immobilizes the axial rotation of the converting gear-train, in order for the conversion to be activated. Hence, the goal of this documentation, is to teach several different means, that maintain the immobility of axial rotation of the dual-drive gear train in order to activate the dual-drive feature, without the use of either of user's hands, thereby conveniently leaving one of user's hands available for holding a work piece.