Instructables

need help with lasers!


i am doing a laser project using three mirrors and motors to make a kind of spirograph. my mirrors are a hard drive platter. what wattage should the laser be so that it can go threw 3 mirrors then be seen properly on the wall at a 2m distance

randofo3 years ago
I just did this with an average red laser pointer (< 5mW). If you get a more powerful laser, it will be brighter, but I am not sure that it will add much at that distance.
pbergeronronronron (author)  randofo3 years ago
i was using a cheap dollar laser i think it was 5mw, i could only see the drawings at less than a feet (using a cd as mirror) but i will soon upgrade to a hard drive platter then we will see
How bright is the room that you are working in?
pbergeronronronron (author)  randofo3 years ago
it was neon lighted, but the room im going to use this in will have non coloured xmas lights. also what does the wave length change on a laser?
im planning on buying this laser, is it a good idea?
http://www.dealextreme.com/p/true-green-laser-pen-5mw-91
It changes the color of the light.

That should be a little brighter.
rickharris3 years ago
You should only need 2 mirrors?
pbergeronronronron (author)  rickharris3 years ago
the more mirrors you add the more modulation it makes
Jayefuu3 years ago
If you're struggling with it maybe you should ask Randofo for help in the comments of his Instructable, perhaps something wasn't clear enough?
Any small laser will be fine. There is no need for a lot of power at all at that range

Steve
+1. An ordinary $10 laser pointer will do just fine. For that matter, a slide projector with a pinpoint slide, focused properly, would also work.

(Related: websearch "edmund scientific musicvision", a system which generated random lissajous figures based on music input by mounting mirrors loosely to speakers. It was originally used with a slide projector or similar focused light source, but some versions of it worked just fine with lasers too. Uncontrolled, but had the advantage that the whole figure came out of a single mirror... and multiple mirrors could be mounted to a single speaker to cheaply fill a wall with lighting effects.)