I built my own laser vortex with an inexpensive battery-op laser pointer. It worked just fine all night, though I think something with a plug would be best for running multiple nights.
That said, the problem I had with ours was that the motor spinning the mirror (essential to the round projection) would wobble, vibrate, and do its best to move around. So I said screw that, and built myself a shadow projector instead. Wooden box, flood light inside, front covered with a green lighting gel and black cardstock to black out all but a ring for projecting through. Kind of bulky, but it has no moving parts and no laser to potentially blind somebody.
Also: a computer projector can do the same thing. I played with this idea before deciding to build the static shadow projector.
That said, the problem I had with ours was that the motor spinning the mirror (essential to the round projection) would wobble, vibrate, and do its best to move around. So I said screw that, and built myself a shadow projector instead. Wooden box, flood light inside, front covered with a green lighting gel and black cardstock to black out all but a ring for projecting through. Kind of bulky, but it has no moving parts and no laser to potentially blind somebody.
Also: a computer projector can do the same thing. I played with this idea before deciding to build the static shadow projector.