Floppy drive stepper motor scanning system

Parts:

2x 5.25" Floppy drives - the kind with the nice stepper motors
1x Parallax BASIC Stamp II Microcontroller
1x Laser
2x Mirrors
1x Old AT computer PSU

Using a pinout from the internet you can convert old floppy drives into stepper motor controllers - once converted they have 2 logic inputs, one for direction and one for stepping. I glued two small mirrors to the motors and Attached the motor driving boards to my microcontroller. Then with enough imagination and programming probably any number of designs and effects could be created for this system.

There are several major drawbacks to a system like this compared to real galvos. Stepper motors have a set "resolution" of sorts since they are only able to make a certain number of steps per revolution compared to galvos which move proportionally to the amplitude of an analog input signal. The second drawback is scanning speed. As you can see from the following pics when the scanning speed is increased the image begins to distort as the motors are unable to keep up with the scanning.

But heck, it's more fun than just a spirograph since you can do text and beamshows

Ok, onto the pictures

setup

running

max microcontroller operating speed

Dude - THAT is awesome ! Where did you come up with the idea ? Post some source code, and "stamp" programming instructions ?

SenKat said:

Dude - THAT is awesome ! Where did you come up with the idea ? Post some source code, and "stamp" programming instructions ?

Click to expand...

the idea came from when i had taken apart a drive a while ago for use with my microcontroller for little automation type things, but then i thought of getting another for an XY scanner - unfortunately this was all programmed step for step so the entire program code would be thrown out for a new design - i hate programming so i wasn't able to make an actual easy interface for it.

I remember when you showed this to us on IRC. I don't think I could do something like this on my own from scratch any time soon.

that is really good for steppers man! my rgy uses steppers, and with it down really slow, i can write out "welcome", but it does the individual letters, so you can't read it, but when you speed it wright up, it gets a wobbly and unstable. almost like it looses quality with speed?

Dam thats a cool idea, its like a 2K scanner ;D a mini scanner

a 2K very unstable scanner! ;D ;D

Well not bed considering it's made of scrap ;D a dodgy 2k scanner

Hmm, im trying to make boomdogs x/y scanner and thought of using floppy drive motors but that has put me off them a little now. Looks cool making the text but I would rather have it smoother.

Nether the less, have fun with it!

Could anybody please tell me what the "K" stands for? Or at least give me a search term for google?

K is for thousands. So a 10K scan speed can do 10,000 positions per second. The higher the speed you can do more complex and smoother animations.

XG

It represents the speed of a scanner, the higher the the kpps the better the image or scan. The "k" represents thousand, eg. 30K is actually 30 000. pps got no clue, most probably pixel per square or something like that.

Oh right makes sense now ;D