Step Motor is not very good for Animation Laser.

It suit for beam laser light Show.

After some searching i have found out some info on using steppers that make me wonder about how would i go about using them.
1. get the largest step possible.
2. the most steps per second.
3. put constant current on one of the coils to act as an electronic spring.
4. Use a varying ac audio amp to power the other coils.
when using the amp make sure the power is set just high enough not to break away from the holding coil.

I have found a motor with a 7.5 deg of step thus i could get around 14 deg of motion easily. (don't want to break away from holding coil so leave the .5 as a buffer.)
It might seem that using a cnc controller is over kill but i could use a cpu 5.1 surround sound card. but what controller to use.

What mods would i have to do to the card to get it to output enough power to turn the motor?
Any software use sound?

If you're going that route, you'll need an external amplifier like a stereo or dedicated audio amp. No current software (except some really old one I think for macintosh computers) use this type of output system. Even then all you're going to be able to draw is some scribbles or lissajous figures.

Commerical stepper units actually step the motors with a stepper motor driver, and a controller to send the step/direction signals. You can make basic shapes and some text this way. Otherwise you really should be looking into some commercial scanners.

My first scanner was built as you describe using steppers. But, I used a microcontroller instead of a sound card. It was a fun project but pretty worthless for anything but very very very basic shapes (ie a square or a line)

So it still seems using my micro controller from my cnc machine will be the best way to drive them. Now i just need to find the motor with the most steps per second.
How many steps or equivalent does a sp20 go?
if i could get a step per second of 1000 that would be over kill for a beam show but maybe just enough to write letters?
i know i am not going to get any where near the results of a sp20 but i just would like a benchmark.

You also want to get the one with the most steps per revolution. This will increase your resolution for drawing images.
There is no "step equivalent" for the SP20, they are completely analog.

I used stepper motors with large steps and only varied between one step. It was easy to make it work that way.

I have built a 2 stepper scanner using 200 step steppers.

When I get back home (working away currently) I plan to document the project. I am using an Arduino to drive the steppers, I have also ordered Alaegro stepper controllers that provide up to 1/16th microstepping.

I managed to get some very good beam effects using blanking. You can't acheive the same effects as with Galvo's, you have to work within the constrains of steppers. The steppers I used came from sparkfun (12V bipolar) they have minimal over-shoot.

Stay tunes.

I'm more interested in the >$100 CNC. heh.

well i made a thread about that a while ago,
Its not super hard the hardest part was picking the motors and controller but building it was the fun part.

Found it, thanks. Didn't realize it was on this forum heh.

yup but a warning for you.
i can do wood and aluminum, but i would advise you use it on them for art purposes.
Depending on how good you are at building one needing it to cut perfectly just wont happen.
But it is amazing for circuit boards. the small shake my old machine did never screw up a board.
it did straight lines perfectly but when it was doing circles they sometimes looked a bit off. nothing huge but some sanding was needed.
if you want to talk about it further its fine to necro post the thread.

Heh, if I build one, it'd likely be all aluminum and have something more substantial than a dremel for a cutter.

Though I think my goal would be heatsinks. So it would have to be able to deal with aluminum and copper.

well mine was able to do wood, in some cases wood can be much much harder than copper and aluminum.
Also for your cutting tool a 1hp plunge router will do almost everything you need, ever even on the hardest wood.
but for most people you will want between a 1/4 and 1/2 just for space and weight.
buy the cutting motor last.
http://www.harborfreight.com/power-t...ver-40432.html
things with these flex shafts help keep the head light.
build the machine and try the 1/4 if it works your good if it does not return it and go for the 1/2 and so on.
I would have built mine out of aluminum but i did not have access to a welder.
You can make these very stable with no wobbel.
Dont use any type of drawer slides for the love of god.
i learned my lesson try the steel corner bars with skate bearings.
i say go with steel over aluminum they will last forever.
if you want some links i will see if i can dig them up again.