From parallel diamonds: Points (acting as wave ends) Split Circulate and Hinge, as centers Outlet i.e. Cast 1/4 around the center as a pivot then Cast 1/4 around the end as a pivot. Gives parallel waves.
Hourglass Outlet - From an hourglass: Hourglass box dancers (points) Split Circulate (as above) and Hinge; centers (in diamond) Drop In (1/2 Box Circulate) and Cast 1/4 around the infacer. Gives parallel waves.
Hourglass Inlet - From parallel waves: Outer actives (out-facing end and adjacent center) 2/3 Recycle (Hinge and Split Circulate), inner actives Cast 1/4 pivoting around the center dancer and 1/2 Box circulate (Diamond Recycle). Gives an hourglass.