I followed the Instructables how-to in a general sense and used a computer cooling fan with wall wart instead of a smaller motor with batteries and zip ties instead of beam clamps. One thing I realized is that the batteries die within an hour so I would have to constantly watch for when the batteries start dying. So instead of shutting down the Haunted House for minutes while I change it out, I decided to use 1/2 inch pvc with a small piece of cardboard to help push the ON button down. The clip that holds it a shirt pocket like a pen makes it fit snug into the 1/2 inch pvc tube. I can slip it out, change batts and back in within 30 seconds. The pvc pipe is zip tied into place and I just adjust once it is back in to hit the center of the mirror.
I didn't use a chiller because I want the fog to quickly head upwards to get the right swirling motion. If the room is just full of fog it is just a green glow and not really all that interesting. I have my laser light vortex in a 5x10 room that was previously all closed in with plastic and curtained entrance/exit. I had to remove the roof to let the fog move out quicker.
One other thing that I noticed is the pc cooling fan. It was suggested to use that but to cut off the fan blades because of the sound it could make. If the fan is turning in the right direction pulling the fog towards the fan, it could actually make the swirling effect even better. However, I don't really know since I had cut the fan blades off before testing it. Maybe even just cut half of the blades off might work well too. That is something to try when this pc cooling fan dies and I have to get another motor to turn the mirror.
I use a 400 watt fog machine in an enclosed room so I can't really speak for outdoors. However, I am hesitant to try any fog outside since it is so windy in Michigan at the end of October.
For the person that wants to build a flat plane of laser light with fog effect, what about a mirror mounted to something that is more of a cylinder. Maybe a few mirrors...
Take a vertical dowel of some kind, glue some mirrors to a horizontal row all the way around, and when it spins, you could get a 90 degree reflection on a level plane. If that doesn't make sense I drew up a picture.
Flat Plane laser pointer fog effect on Flickr - Photo [email protected]@[email protected]@http://farm4.static.flickr.com/3187/[email protected]@[email protected]@[email protected]@[email protected]@59b615a82d
I thought those tips might help someone else.