We ask for 2 days on POLARIS to study the cubic-tetragonal phase transition in the frustrated spinel ZnV2O4. This transition is reported to occur at 52K, and is followed by a magnetic transition to a k=(001) AF structure at 44K. However, it is not clear, and somewhat controversial, what the precise symmetry both of the high temperature cubic and low temperature tetragonal states is. In particular, the proposed highly symmetric I41/amd tetragonal symmetry is inconsistent with predictions of orbital order concomitant with the structural transition. We have developed a rapid microwave-assisted preparation of high quality samples, which we propose to study on POLARIS to shed new light on this complex material.