This laser vortex tunnel will be used in my home haunt this year (2009). I bought one last year at the Midwest Haunters Convention in 2008 for the Haunted Palace in Marion, OH. I was hoping to buy one for myself this year at MHC2009 but the vendor wasn't at the show so I had to build one for myself instead.

The unit is mounted on a 5" x 9" board. The protective blue coating still covers the first surface mirror in the first few photos. The mirror is mounted on the fan using sticky back velcro. The mirror has to be attached at a slight angle, so I placed a double layer of velcro under one edge. The fan has 3 speeds: 1200 rpm, 1600 rpm, or 2200 rpm. The 1600 rpm provides 25 rotations per second which is just right to create a solid tunnel of light to the human eye. To save time and make things easier on myself, I went with 2 separate power supplies instead of trying to make a 12v to 3v converter so the thing could run on a single 12v power supply. The fan runs on 12v and pulls 250mA. The laser runs on 3v and pulls 260mA. (You may be able to use your old power adapters from things like scanners or cable modems. Just make sure the voltage is right and the mA are higher than what the laser and fan require.) A single power switch turns on the laser and the fan. Get help with wiring the circuit if you aren't sure of what you're doing.

I placed a nut in the bottom of the board for mounting the unit on a tripod for better aim. The fan is connected to the board using 2 zip ties that are visible from the bottom. The power to the laser also runs along the bottom.

The laser is strapped on a spare piece of plastic from an old baby gate using a zip tie. In the early photos an empty aspirin bottle covers the laser, but I had to remove that because it caused the laser to overheat, grow dimmer, and eventually go out completely. I'm sure it didn't help that I was testing it out in an 80+ degree garage. To solve the problem, I removed the aspirin bottle that covered the laser and instead covered the unit with a sheet of cardboard, giving it the look of a mailbox. This creates a tunnel of moving air which helps to keep the laser cool and also protects all the parts. I ran the unit again in my basement even longer than I had run it in my garage and the laser didn't dim at all.

I added 2 heatsinks to be extra sure that the laser doesn't overheat. I fashioned the bottom heatsink from the aluminum face plate from an old Radio Shack project box. I hammered the curve into it using a dowel rod as the form. The top heatsink was permanently borrowed from the guts of an old broken Dell LCD monitor. I used a Dremel to carve a shallow curved groove down the bottom of the heatsink to increase the amount of contact between it and the laser. I used heatsink thermal compound between both of them and the laser.

I painted everything flat black so it isn't visible once people step outside the tunnel.

Parts list:

Laser - green 5mW 532nm, $30, http://www.instapark.com/category/laser-modules/
Fan - TriCool 120mm, $20, http://microcenter.com/single_product_results.phtml?product_id=0253118
First Surface Mirror - $5, http://scientificsonline.com/product.asp?pn=3052324&cmss=first+surface+mirror
3v and 12v power supply - you need 2, $20 each, http://www.radioshack.com/family/index.jsp?categoryId=2818335