The transport properties of PdCoO2, a material with a hexagon-shaped Fermi surface, are investigated in the two contrasting crystal directions by ballistic electron deflection in a perpendicular magnetic field. By progressively reducing the device size, we systematically examine the impact of geometric confinement on the electron propagation. The measurements reveal clear orientation-dependent features. The quantitative and qualitative agreement with a theoretical model based on the Landauer–Buttiker formalism allows to distinguish features originating from classical size effects and from the intrinsic anisotropy of the Fermi surface.