A solder jet apparatus is disclosed. In one embodiment, by way of example only, for each of the small data chunk, a signature is generated based on a combination of a representation of characters that appear in the small data chunk with a representation of frequencies of the small data chunk. The clearance between the add-on tube and the camera lens is from 0. The distances between the previously punched holes and the subsequently punched holes measure at least the distance corresponding to the fine interval. Each of the coil layers generally comprises a plurality of electromagnetic coils arranged circularly around the shaft in plane that is substantially perpendicular to the shaft.