  Recently, there have been significant efforts to guide mechanical energy in
structures by relying on a novel topological framework popularized by the
discovery of topological insulators. Here, we propose a topological
metamaterial system based on the design of the Stewart Platform, which can not
only guide mechanical waves robustly in a desired path, but also can be tuned
in situ to change this wave path at will. Without resorting to any active
materials, the current system harnesses bistablilty in its unit cells, such
that tuning can be performed simply by a dial-in action. Consequently, a
topological transition mechanism inspired by the quantum valley Hall effect can
be achieved. We show the possibility of tuning in a variety of topological and
traditional waveguides in the same system, and numerically investigate key
qualitative and quantitative differences between them. We observe that even
though both types of waveguides can lead to significant wave transmission for a
certain frequency range, topological waveguides are distinctive as they support
robust, back scattering immune, one-way wave propagation.
