The ability to synthesize nanomaterials of particular shape, size, and composition is an important scientific goal and necessary for developing advanced materials in applications ranging from the biomedical to catalytic. Solution-based methods have commonly been employed to tune shape of nanoparticles via the selective adsorption of ligands; however, newer cluster beam gas condensation techniques have also shown promise in this area. Here we have developed a synthesis for copper nanocubes using a commercial sputtering-based gas condensation system. We demonstrate that copper nanoparticle shape in this system can be manipulated by tuning a few key growth parameters. Copper nanoparticle shape is shown to be highly sensitive to the geometry of the sputtering target, carrier gases, and length of the aggregation zone. This work adds to the toolbox of nanomaterials that can be grown in a cluster beam-type system and highlights the need for careful consideration of the many parameters involved in such an experiment.