Answer
Wave springs can be 'stacked' to modify the system's performance. Stacking in 'Series' (crest-to-crest) increases the total deflection while keeping the load constant ($k_{total} = \frac{k}{n}$). This is used when a large stroke is required in a small radial space. Stacking in 'Parallel' (nested) increases the load capacity while keeping the deflection constant ($k_{total} = k \cdot n$). For series stacking, the waves must be aligned crest-to-crest; this is best achieved using a multi-turn crest-to-crest spring rather than individual rings to prevent misalignment. For parallel stacking, the springs must be nested perfectly. In both cases, guides (shafts or bores) are mandatory to prevent the stack from 'buckling' under load, similar to how a long column buckles under compression.
