In this paper, tools for the design of air-core tubular linear electric drives are established. The tools include numerical techniques to efficiently calculate coil inductance and magnet/coil coupling for arbitrary turn placement. The structure of the state model of the system is tailored to facilitate rapid computation enabling comprehensive design optimization. In addition, a null zone is included to efficiently capture the off-state in the diode rectifier model. The tools are highlighted in the design of an energy harvest system that consists of a machine, a diode rectifier, and a capacitive energy storage device. A comparison with hardware measurements is used for validation.