  The quantum valley Hall effect (QVHE) has been observed in a variety of
experimental setups, both quantum and classical. While extremely promising for
applications, one should be reminded that QVHE is not an exact topological
phenomenon and that, so far, it has been fully understood only qualitatively in
certain extreme limits. Here we present a technique to relate QVHE systems with
exact quantum spin-Hall insulators that accept real-space representations,
without taking any extreme limit. Since the bulk-boundary correspondence is
well understood for the latter, we are able to formulate precise quantitative
statements about the QVHE regime and its robustness against disorder. We
further investigate the effect using a novel experimental platform based on
magnetically coupled spinners. Visual renderings, quantitative data and various
tests of the domain-wall modes are supplied, hence giving an unprecedented
insight into the effect.
