We're very interested in this "traveling out the spoke of the wheel" formation. Never heard of (or seen) this before. We can visualize what you must mean, but would love to se a video of this. Any online links to a clip of a sample of this, in any dance style?
As to the "waterfall" formation, are you referring to a "Virginia Reel" type format? ... Not sure how or when the partner-switching part is accomplished since we have never learned this style. We'd like to hear more about it or see a video clip, though.
Have no idea if there are videos of any of this. Can't find any on YouTube. Sorry. I will also ask our instructor where her 'wheel' mixer comes from.
Here are more detailed descriptions that might help:
In the "wheel" mixer, the men start with their backs to the center, almost shoulder-to-shoulder to form a rather tight circle. The men are facing their first partner and begin dancing outward along a radius (spoke). We have used only a single basic progressive pattern with a left turn on the end which puts each couple on a circumferential LOD (the rim). (The 'spokes' are rather short, but you could probably use two figures on the radial component if you wanted a larger wheel.)
We now dance counter-clockwise on the circumference of the larger circle (rim), using two basic traveling figures and ending with a turn into a PP which aims us back toward the center (hub). Now we dance on the radius back toward the center (hub) with the man doing a 180-deg maneuver at the end so that he stops with his back to the center once more. The exchange of partners occurs at this point -- by passing each lady to the left with a simple UAT movement.
It is a little tricky to maintain a nice neat circle as everyone has different stride lengths and the less experienced can't always achieve the needed degrees in their turns. It helps to put a stool or a person at the very center of the circle (axle) to serve as an 'aiming point.'
*********
In our "waterfall" mixer, the leaders are lined up along one of the long walls of the floor and the followers are lined up along the opposite long wall. We join with a partner by walking along a short wall and dance the length of the floor; separate, and rejoin our respective lines. If it appears that you will get the same partner the next time around (rare), you allow the person behind to step out ahead of you to claim a partner.
We also modify this pattern by putting both lines side-by-side along the same long wall which allows for more room to take a longer line of dance before dropping off your partner. (Across the short side, down the long side, back across to the lineup-side for drop-off.)
Hope this is useful, TOB.