Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Building a scanner.

Keep in mind, those pics Mario took are most likely long exposures, you would be able to see them scanning that in real life.
 





Thats cool. i just want to know the motors he used. i am not looking for high grade that will be much later. this is me getting my feet wet.
 
I used motors and drive circuits from old floppy drives, I'm sure you could get better performance if the motors were driven harder. I had to program each step manually in PBASIC to the microcontroller, there was no interface or anything.

Click Image to Enlarge

Click Image to Enlarge
 
Wow i got lots of old floppy drives heck i will try those first as that make this free then.
 
they came from 5.25" drives, you have to make sure the motor is the right kind since newer drives have really cheap motors that won't work once you take them out of the little holder
 
hmm. i got only newer drives the oldest i got is from a windows 95 cpu.
So as far as motors for this do i want a 1.8 or a 2.7 deg of step? I take it that i want to get the smaller motor around the size of 1 x 1.
 
You want to get a motor with the smallest steps possible, this will give you more usable resolution for the output images. Also, see the red grid I made in the pics? That's about the only lines I could create. Although it can also do slanted lines by sending step pulses to both motors at the same time. But they can't just go anywhere like galvos.
 
Thanks so much for the help. i look forward to posting my results of this build.
i must say i would never recommend doing this unless you already have all the stuff.
 
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.
 
kiyoukan said:
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?
Click to expand...


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.
 
kiyoukan said:
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.
Click to expand...

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.
 
You must log in or register to reply here.





Back
Top