An automatic tape feeder for use in component placement machines includes a novel sprocket wheel for driving component carrier tapes to a gross position by an electric drive motor. Before the electric drive motor reaches the final position desired, it is deactivated or turned off. A novel indexing cam is connected to the sprocket drive wheel. A spring loaded pawl or positioning cam is moved into a vee-shaped groove on the indexing cam so as to achieve an actual fine position of the indexing cam as well as the teeth on the sprocket wheel. By first achieving a gross position with the drive motor and then a fine position with an indexing cam and pawl, it is possible to achieve a positioning accuracy in a pick up station which is as accurate as the sprocket holes and component pockets in the carrier tape. The present invention has achieved accuracies of ± one 1,000 th of one inch which exceeds positioning accuracies of devices known heretofore.