  We determine the Casimir energies and forces in a variety of potentially
experimentally viable setups, consisting of parallel plates made of perfect
electromagnetic conductors (PEMCs), which generalize perfect electric
conductors (PECs) and perfect magnetic conductors (PMCs), and Weyl semimetals
(WSMs). Where comparison is possible, our results agree with the Casimir forces
calculated elsewhere in the literature, albeit with different methods. We find
a multitude of known but also new cases where repulsive Casimir forces are in
principle possible, but restricting the setup to PECs combined with the
aforementioned WSM geometry, results in purely attractive Casimir forces.
