What's the best way to acheive a scanning laser effect?

[Boomerjinks]

So I'm working on a project for Halloween and one of my lofty goals is to have a back-and-forth laser scanning effect.

This screengrab from Event Horizon sort of illustrates my goal.

A solid split beam, like you'd find on a laser leveler is not really what I'm looking for, either, so that's out.

If you can recall the shot of the Nebuchadnezzar hovercraft from The Matrix scanning a landing area, that's another similar effect.

Now, of course the obvious answer is to pick up a laser light show unit, but those things are incredibly bulky, and very expensive. I'm looking for a solution that is hand-held, and hopefully DIY enough to accomplish for less than $100.

So, if you were me, what would you do? Any directions I should be pointed in?

 

[hankey01]

Laser level from hardware store attached to an oscillating fan?

 

[aron42486]

Those laser light show units operate with a static laser and a mirror that spins or moves to produce patterns.

Maybe some kind of oscillating motor with a small mirror attached and the laser of your choice?

Perhaps an electric toothbrush deconstructed and rebuilt...?

 

[robstyle]

Ive done this exact thing with simple hand held laser pens with diffraction grating on them. You can get both on ebay cheaply. The laser pens in question have a "star cap" or "filter" on them that will vary the pattern on a grid. If thats not enough or if you have the time to play around, order some "diffraction grating" and have at it.

Unfortunately you are after something that has a scanning motion but that is a custom job as it will scan the room its designed for. I would look at stupid dancing kids toys and see about slowing down the toys mechanical motion. Zip tie the laser pen to the thing and have a laugh if it works.

 

[Majonaise]

Search laser light show on Instructibles.com.

About a zillion people on there have put together diy laser light shows of varying complexities. As per aron's sugestion, a lot of them use a static laser pointer bounced off of a mirror afixed to a 5v case fan (or a series of them).

 

[iceman]

I've built a few of these, just search for "surplus laser scanner mirrors" they come from used supermarket scanner assemblies and usually include the motor, all for $15 or less -

COPAL POLYGON MIRROR LASER SCANNER - Surplus Shed