I’ve been on a bit of a laser kick lately. I was searching through YouTube and came across Dr. Altman’s “Amazing Laser Music Can” which I thought was a very impressive effect for very little money. I had a spare Sunday afternoon, and decided to make one for myself. If you’re the impatient type, here’s what the final product produces, not too shabby:

Parts

I started off at the local dollar store, which amazingly enough had everything I needed for about five dollars.

  1. Three laser pointers, $3. This personally boggles my mind – an electronic device, relying on the most advanced theories of physics humans have developed, the absolute cutting edge of research less than 60 years ago, now sells for 99 cents. You don’t need to use precisely three, but you’ll probably want at least one. Or else bitter disappointment awaits, because you need a laser for a laser light show.
  2. A package of ballons, $1.
  3. A small mirror, $1.

I also had a few things around the house.

  1. A can.
  2. Duct tape.
  3. Zip ties.
  4. Clothes pins.
  5. Popsicle sticks.

If you need to buy them don’t worry, you won’t blow your budget. Plus, once you have an excess amount of duct tape and zip ties you’ll wonder how you ever lived without them.

Concept

What we’re trying to do is mount a laser so that the beam bounces off a mirror attached to a membrane (aka balloon) stretched across the mouth of the tube. When the membrane vibrates, the path of the laser will be changed in a semi-periodic manner, leading to (hopefully) beautiful patterns that sync up to sound.

Mounting the Lasers

You can do this with one laser, but since the lasers were so cheap I picked up a few. The first thing we need to do is zip tie (or glue, or whatever) one side of the clothes pin to the popsicle stick. This will create a nice little angled place for the laser to mount to.

Then, we need to attach the laser. Another zip tie does well for this, really crank it down to make sure that it isn’t going anywhere. Finally, we need to create some sort of method to ensure the laser remains on for an extended period of time without us having to hold down the little button by hand. Zip ties to the rescue again! Just position it on top of the button, and slowly tighten it until the laser turns on. The zip tie should then be loose enough that you can move it back and forth to turn the laser on and off for as long as you like.

The final product can be seen above. Note that the middle zip tie is loose enough to be moved around as necessary. Make as many of these as you want.

Membrane

Now we need to create the membrane that will vibrate, and that we’ll attach our mirrors to. Remove both ends of the can, by whatever means possible. I suggest finding a can where you can use a can opener (oddly enough) on both ends.

Once you’ve removed both ends of the can, cut the end off a balloon and stretch it over one end of the can. Make sure it’s nice and tight, and then use duct tape around the side of the can to keep it all in place.

The assembled membrane may be seen above.

Assembly

Now to put it all together. The only thing we need to do still is create tiny little mirrors that the lasers will bounce off of. I would suggest breaking a small mirror on your kitchen table, and make sure to get small pieces of glass everywhere. Your girl/boyfriend or significant other will love this, trust me.

Attach the mounted lasers around the edge of the can with duct tape, and turn them on. This helps us to place the mirrors accurately. I used a little roll of duct tape, stuck it to the bottom of the mirror, and then placed the mirror as the laser indicated. Make sure that you stick the mirror on securely, the membrane will vibrate rather vigorously and the mirrors have a tendency to bounce off unless you’ve made sure they’re on.

And that’s it! This little device provides a ridiculous amount of entertainment for five bucks. I’d suggest placing it on your subwoofer vent if you want it to sync up to music (that’s what I did for the video), or singing into it – just try not to wake the neighbours.

If you liked this, check out the Ultimate Home Laser Show.

21 thoughts on “The Five Dollar Laser Show

  1. Hi Geoff,
    Reddit, my source of interesting stuff, introduced me to your pages on gasoline and now lasers. Your reference to the Royal Military College made me wonder if you are related to Cec.
    Stan

  2. Hey Geoff,

    This is very cool, and I see you are at RMC, I’m joining up next week as a NCM LCIS Tech, you might end up being my boss!

  3. You can just put a small mirror onto the middle of the speaker directly with a little double-sided tape – point a laser at it and you get the same effect with even less hassle, used to do it as a kid.

  4. The best way to do this is like so:

    Mount two mirrors at 45 degree angles on the center of two separate speaker cones (Mid range is best for overall detail). Now angle the two speakers/mirrors so the laser bounces off both. Make sure you run a mono signal through both of the speakers for it to look best.

    You will find that this setup is far better, you will get a super responsive light show. Try using a synthesizer instead of the music you’re listening to and jam along. It’s really fun!! Me and my friends used to spend hours creating new and better designs with some really high-powered lasers (lasers that take up half the room with transformers and fill the room with static)!

  5. What dollar store in Kingston sells laser pointers for $1?

    I went to a dollar store in Ottawa and couldn’t find anything remotely close to a laser pointer…

  6. blargle – I went to the one in the Kingston Center, across from the Loblaws. That’s the peril of those stores – often you can find thing you’d never expect, but don’t expect consistent inventory.

    If you’re looking for cheap lasers and don’t mind the wait for shipping (they’re in Hong Kong but at least the shipping is free), DealExtreme is about as cheap as it gets.

  7. Pingback: The Five Dollar Laser Show | 5DollarPlanet.com
  8. Pingback: Home Laser Show | only hacks
  9. Scientific American published a DIY laser show article in the 1980’s with info on building a 2-axis deflector with small speakers, a random distortion disk from gooping up a piece of clear glass or plastic with thick transparent adhesive and mounting it to a slow turning motor and fun with polarizing film and diffraction gratings. It detailed how to make your own diffraction gratings by laying out strips of black tape on a large sheet of paper then photographing it from a distance. The developed black and white negative worked like a polarizing filter.

    Another trick for randomness was gluing plastic wrap over a woofer speaker then gluing a piece of mirror to the plastic wrap.

    IIRC the same issue had an article on building a mercury vapor laser tube from scratch.

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