LASER SHOW PROJECTOR HARDWARE
Intro
If you are reading this page you already have an interest in lasers, and maybe you've even seen a laser show and wondered how they do that.
Waving a laser pointer around in the fog, on a wall or ceiling, or even on a movie screen (sure way to get kicked out of a theater) is fun for a little while, but soon it just becomes annoying to those around you and leaves you wanting more... thinking to yourself "sure would be cool if I could make this do what I saw at the planetarium laser show".
The equipment on this page is mostly hobby grade and was comparatively inexpensive (compared to commercial grade laser projectors). Some if this is no longer available, some of it is salvaged from other equipment (like laser disk players for instance), and some if it is newer higher quality stuff I purchased more recently on eBay. Anyway, I hope you find this interesting and informative. Read on...
Waving a laser pointer around in the fog, on a wall or ceiling, or even on a movie screen (sure way to get kicked out of a theater) is fun for a little while, but soon it just becomes annoying to those around you and leaves you wanting more... thinking to yourself "sure would be cool if I could make this do what I saw at the planetarium laser show".
The equipment on this page is mostly hobby grade and was comparatively inexpensive (compared to commercial grade laser projectors). Some if this is no longer available, some of it is salvaged from other equipment (like laser disk players for instance), and some if it is newer higher quality stuff I purchased more recently on eBay. Anyway, I hope you find this interesting and informative. Read on...
Laser Show Projector Hardware
There are several different types of hardware that work together to make up a laser projection system. The following links (when I finally get the pages done) will take you to the separate pages that describe the different aspects of a system.
- Laser Scanners
- Special Effects
- The Computer
The laser "scanner" pictured here is one of the more common 'beginner' type units you might see advertised in science or electronic hobby equipment catalogs and magazines. It uses mirrors attached to low voltage variable speed DC motors to create limited circular patterns, but this is very much more desirable than just flicking a laser pointer randomly about. These are very inexpensive and fun for a while, but their functionality is limited to "spirograph" type images. Another variation of this design is to add another motor to increase the complexity of the designs.
This little unit was my first attempt at building a usable laser scanner. I obtained it from eBay, like almost every piece of laser equipment I have, for about $15 or so. Not too bad for starters. Anyway, I decided to design and build an electronic X/Y controller for this little scanner, anxious to see what it was capable of. I added blanking (explained elsewhere on this site) to make things a little more interesting, and had myself a rudimentary laser "projector" when completed. A laser projector is normally a complete system including a scanner, a scanner driver, a laser, a computer interface, a computer, and laser show control software. This projector incorporates just a scanner and a hardware controller with knobs to vary the pattern and blanking. It was fun, and still is, but it is still very limited in capability. This two axis mirror assembly was salvaged from an old laser disk player.
This interesting looking little assemblage was my next little creation, based on the ideas I ready about in some laser forums, and works just like the "lumia" wheels contained within some professional laser projectors. It's obviously the low budget version. The lasers are just typical cheap red 5mW pointers held by a "helping hand" part holder available from Radio Shack or other electronics stores, with the beams showing through the rippled glass of a candy dish. This really falls under 'special effects', which is addressed on another page, but I included this one here because it was part of my first laser show and was used right along with the scanner pictured above. But that is part of another page also, so no need to go into detail here. I just wanted to show this as an example of a reasonably simple device with a very effective and powerful impact. More on this on the special effects page. If you have a laser pointer and can find something with rippled class (or even clear plastic) just shine the laser through it and you will see a really cool and amazing special effect.
A small step up from the above scanner is this unit comprised of two modified stepper motors. They have hardware attached which prevents them from spinning like they normally would when actuated, as well as having lengthened shafts with very small lightweight mirrors epoxied on. With just amplified audio driving these you can get more intricate patterns projected since they are much more responsive than the little voice coil type scanner above, with it's much heavier mirrors. Actually, the mass and dimensions of the mirrors is very important to the responsiveness of the scanner, along with several other factors including the mass of the rotor and the drive circuitry. This unit was slightly more expensive than the voice coil scanner above, but worth the extra. But there are better scanners still...
This was a kit scanner which included a pair of interesting low mass motors, the driver electronics board, and a computer interface. Sold by a small company called "SVS Kits" (no longer available), this unit is probably closer to a projector than a scanner, but it is shown here complete because this is the way it came (as purchased, you guessed it, on eBay). After mounting the parts on some aluminum plates, I had high expectations for this and another one I found on eBay (an earlier version) but soon discovered they very difficult to align and tune. Once properly aligned, these were capable of producing actual graphics, which my previous scanners could not. Problem is, they would not keep working properly and failed before or during the few shows I did using them, which was very frustrating. Since the introduction of the very inexpensive scanner / driver amp sets available from China, I have given up on the SVS units in favor of the new ones I've purchased.