Intro: Laser Vortex
I have been making the laser vortex for several years as a Halloween affect on my front porch, everyone loves the affect. Finally, this year I created a Halloween site showing others how to make one of these. The video of this can be found on http://haunted.hyperreactor.net. Its made with a laser pointer, small motor, and a mirror creating an effect similar to what you might see at Halloween Horror Nights but on a smaller scale and much cheaper.
I have uploaded the how to videos and added them the the end of this instructable along with some example videos of the vortex in action. I have said this a hundred times but once again, it is even more spectacular to see it in person. There is so much depth that the video dose not bring out.
Step 1: Laser Pointer Mount
We will be mounting the laser on a scrap piece of wood. The one used here is about 1 ½ by 1 inch and cut to about 6 or 7 inches. A 2 by 4 would also work well and can be found in your local hardware store. It will probably cost you less than a dollar if you need to purchase this piece.
A beam clamp was used to secure the laser pointer to the wood base and hold down the “on” button continuously. Three were used, two for securing the laser pointer in place and one to hold down the button. The one holding down the button should only be tight enough to hold the button down, if it is too tight it may damage the button. These beam clamps would be easy to find in the electrical section of your local hardware store near the electrical conduit for less than a dollar a piece. Just make sure there is a screw hole on the clamp to mount it to the wood base.
Step 2: Beam Clamp Alignment
Align up your beam clamps on the wood base making sure all points rest evenly on the laser pointer. You will not need to tighten the bolts down very hard to secure the laser pointer but properly aligned clamps will hold it more securely while placing less stress on the pointer. The placement of the clamp used to hold the button down may differ from this image. Different laser pointers sometimes have the button in different locations.
Step 3: Clamp Attachment & Laser Pointer Protection
Screw the clamps to the wood base. Make sure the clamps stay properly aligned. Most beam clamps have only one screw hole and will twist slightly when secured so you may need to hold them in place prior to tightening them down all the way.
Self adhesive felt pads were used on any point where the clamp came in contact with the laser pointer. In this case there were two for the clamp side, one for the bolt tip, and two for the lower portion of the clamp.
Step 4: Cut to Desired Length
The wood was then cut to the desired length.
Step 5: Tripod Mount
The wood base could be hung or propped up to point in any direction you need but mounting it to a tripod was desirable in this case. Tripod attachments for cameras are portable, inexpensive and can be found in many styles and sizes.
To screw the wood base to the tripod, a 5/16 inch Tee Nut was used. Once again this was found in a local hardware store for less than a dollar but you will usually find these in the nuts and bolts department.
To install the tee nut to the wood base, a hole about ¼ inch deep was drilled on the bottom just big enough for the shaft of the nut. It is best to center the hole to ensure a well balanced mount but be careful not to drill directly over the screw securing the clamp unless there is space for it. The tee nut is then hammered into place and ready to be mounted.
The final product mounted to a small tripod. Remember when attaching the laser pointer to tighten the bolts enough to hold the laser in place but not break it. The bolt for the button should only be tightened enough to hold it down.
Step 6: The Reflector Module
The reflector module is really a simple concept but it can be a bit difficult to construct. Its job is to reflect the laser beam at an angle that constantly changes to make a circular pattern. This is accomplished by placing a mirror at an angle on the shaft of a small electric motor. As the motor turns, the angle is changed making a circular pattern.
In a foggy room, we can see the pattern as a cone from the striking point of the laser on the rotating mirror outward. With a dense wispy fog created by a small fog machine, the vortex affect we desire is created by reflecting more of the concentrated laser light off of the denser areas of fog.
Step 7: Motor Mounting
We will start out with a small electric motor extracted from a battery operated personal fan. You can find these fans in dollar stores and places like Wal-Mart that sell them for as little as 50 cents.
The motor was mounted to a gutter bracket purchased for about one dollar at a local hardware store. The gutter bracket is strong with pre-drilled holes for mounting both the motor to it and it to whatever we want.
To hold the motor to the bracket, a piece of insulated 14 gauge solid core electrical wire is bent over the motor housing with the ends placed through two of the pre-drilled holes in the bracket. The ends of the wire are then bent around the bracket to secure the motor on the bracket. This is the same type of wire used in the walls of your home and is very useful for many different things. It's strong, pliable, and cheep. Find it by the foot or in pre cut lengths in your local hardware stores electrical department.
Step 8: Mounting the Mirror to the Motor
Mounting the mirror to the shaft of the motor can be a perplexing problem. I was told to try a hobby shop for the simple pre-made piece so it would be easy to build but this may not be easy for everyone to find. Here is a design that should be easy for most everyone to find parts to make and do. (The attached fan blade could be used but the blades would need to be cut away. These blades would create wind causing the fog to dissipate along with the vortex affect.)
Find a metal bottle cap in good shape, the twist offs from beer bottles are perfect because most twist off caps are removed without damage to the cap. Use a nail no larger than the shaft of the motor to punch a hole in the center of the cap. Using a nail as a punch rather than a small drill bit will give us some added grip on the motor shaft that we could not get with a clean drilled hole.
Step 9: Angle & Hold Mirror in Cap
We will be mounting a one inch round mirror at an angle in the cap. This is a small angle but sufficient for creating the vortex. The mirrors can be found in the craft department of most stores such as Mal-Mart or at a craft store. They usually come in packages of 10 or 20 for less than two dollars.
Three notches will be bent on the cap to hold the mirror securely in the cap and at an angle. Two of the notches need to be bent as close to the edge of the cap rim as possible so the mirror can extrude as far as the cap will allow. A small piece of foam is used to prop the mirror up from this point where the 2 shallow notches are. The one used here was part of a foam packing peanut.
Once the notches are made and the foam is in place to prop the mirror, the mirror is placed in the cap and the final bend is made to secure it at its angle. Be cautious not break the mirror while doing this.
Step 10: Mounting the Cap to the Motor
Mount the cap on the motor using the hole punched earlier. This should be a tight fit holding it securely but the metal bent out from punching the hole can be used to make a tighter fit if needed. Using an adhesive such as super glue could also help secure the cap on the shaft if needed.
Step 11: Power for the Motor
These small motors are usually powered by two AA batteries, 1.5 volts each for a total of 3 volts. No where near the full speed of this motor is needed so we will be using one AA giving it 1.5 volts. If you know how to reduce the voltage down further it is recommended so vibration of the unbalanced cap in the motor is reduced along with noise but this how-to will not be going into that much detail.
The terminals on the motor for supplying power can be soldered to electrical wire or simple alligator clamps could be attached to make the connection if soldering is not an option. A battery holder from Radio Shack or an electrical shop is best for holding the wire on either end of the battery but I have gone as far as using an old remote control to hold the wires in place if there wasn't one at hand. Polarity (the + and - side of the battery) is not important, the motor just need to spin in either direction. If you have not mounted the bracket with attached motor to something like a scrap piece of wood, now is a good time to hold the device in place before applying power.
Once the electrical connections are made you will likely see why we don't want it to spin so fast. These cheap motors are fast and loud especially when they have not been loaded down with a larger object to move.
Step 12: The Fun Part
Video of Halloween 2006
I recommend watching the video if you can. It contains some ideas for other more suitable motors that could be used like computer case fans. A higher voltage DC motor could also be purchased at your local Radio Shack, electrical store or hobby shop. Using a higher voltage motor and placing a lower voltage on it is a good way to reduce the speed for smoother operation.
Project Video Part One
Project Video Part Two