This is my theory of how David Hamel's devices involving magnets attached to wobbling cones worked. It is derived from conversations with David and my extrapolations from there.
The initial wobble of the magnets induces an electrical current in the metal cones and the exterior shell. This results in a separation of charge across the skin of the cone. Charge leaks out any sharp points, ionizing the air. The wobbling of the cones causes the ionized air to move around, including away from the sharp points, allowing more ionization. This ionized air fills the drum, including the area between the wobbling magnets located at the cone rims. This fulctuating magnetic field in the presence of ionized air results in a tapping of zero point energy. Somehow there is feedback which sustains the wobbling. If enough zero point energy is tapped then gravity effects may happen.
Some support for this theory can be found in the results of my experiments with my 45GD mark 2, using a motor to cause the wobble.
What of this theory is David Hamel's and what is mine? The necessity of air flow all around the cones is something David Hamel stressed repeatedly. Also, on many occasions, David told me that between the repelling magnets at the cone rims is where the zero point appears (quoting roughly from memory.) He would often speak of the zero point appearing at the center of a vortex. On one occasion we were in his kitchen and David was draining the sink and pointed to the resulting vortex in the water and said that was like the hole into the zero point. David often adopted terms from standard physics for his own use, where that use might be entirely different. This may or may not be the case here with the term "zero point". David also said that a red glow came from the direction of the garage when he was awakened by the explosion of this 45GD. Ionized air typically looks purple in color, which some may call red. Also, David did tell me "The cones are what make the invisible (air) become visible (the air becomes plasma)." The text in parenthesis were clarifications I got from him. David also told me that I should not attach the ring of magnets that repel the cone magnets directly to the inside of the 45GD otherwise I would get electrocuted. That doesn't mean he didn't though.
For more on my conversations with David Hamel, see my Meetings with David Hamel page.
Since zero point energy is really the result of waves travelling on the fabric of space between all particles, tapping zero point energy would have an effect on those particles. Just after David screwed the garbage-lid cap on one of his devices, the one which flew away, he ran into his house to get a camera as his wife Nora yelled out "The TV went out!" Another of David's devices caused double exposure on camera film, TV interference and cars to stop in the street. All these effects would likely be indications of tapping zero point energy. Tapping zero point energy may result in particle creation, e.g. electrons. This would further ionize the air.