Connecting a stepper from a scanner to the board

Hi there,

i am looking for an elegant solution to connect a stepper which I'd like to use from an old scanner to the arduino. I'd like to control the motor.

The Motor is the one that controls the sliding mechanism in an old CanoScan N670u , which could be very useful in a tinkering project.

I have attached some fotos of the piece but its kinda blurry, due to my crappy cam :-/

the yellow/orange strip are the 4 lines to the motor. I assume there might be a good way to plug this to a board somehow.

Unfortunately, I have no idea how to approach this :-(

Can you guys help me out?

Your first step would be to get a multimeter, and ohm out the lines to know what lines control what coils and how they are arranged (its probably a bipolar motor):

If it isn't a bipolar stepper, it could possibly be a DC servo motor with a really cheapo single-output opto-sensor for feedback (but I doubt it)...

Are there any numbers or other data on the motor? Finding a datasheet, before you destroy the Arduino plugging the stepper motor directly to it, would be a good idea.

thanks so far..

on the backside of the motor it reads clockwise: 1 9 3 A

Does that mean sth to anybody? Where can I get specs for pieces that have been built into commercial products?

try this one

thanks tektro69, but this is not giving any indication about the motor, right?

Hi zaph0d,

Do you still have the remains of the scanner? When i dismantle something i try to measure things like supply voltage, current, digital levels etc. with a multimeter before i really take it apart. Together with datasheets of some of the chips ([u]if[/u] you can find them) i can usually guestimate properties of the scavenged parts.

Hope this help,


As crOsh answer #1 and web link explanation

Usually small stepper motor is bipolar With simple multimeter you should find on 4 contacts the 2 coils A and B

After that label first coil 1A 2A And the second 1B 2B

Good luck :)

I hadn't thought of salvaging parts from old IT equipment.

Any tips on things to look out for? I've loads of old equipment about the place.

I've loads of old equipment about the place.

First tip would be to know what you are taking apart - do a little research on the item before you tear into it. If it appears or looks like it comes from before 1985, it may be VALUABLE.

I once dismantled (as a stupid kid) a transistorized calculator with a metal wire delay line memory and nixie tubes - and then got rid of the parts in a later move from my apartment about 18 or so years ago. I would give my eye teeth to have it back, whole. I am not sure whether it is worth money or not, but it would look nice in my antique computer collection.

Anyhow - do your research; don't just take stuff apart because it looks old and worthless; there might be somebody out there who would be willing to pay some good money for the item (and nowadays there's Ebay and the internet to find this out - it would've been a near impossible task for me to have done that back then with that calculator).

For most things, though - once you've weeded thru stuff - old printers and scanners make a good source of parts. I have also found that old copiers can make a good source of some parts as well (beware of the toner, though!). Old computer mice (except the really old stuff) used optical encoders for positioning that can be salvaged. There's always computer fans and such to be had from old power supplies and the like (you could also recycle a power supply into a bench supply if you wanted to - tons of information on the internet on how to do that).

Stay away from old CRT monitors unless you -really- know what you are doing; while there can be some interesting parts (depending on what you want to do - the flyback transformer, for instance, can be used for high-voltage experiments) - it can be dangerous to work with one (dangerous as in it can kill you), unless you know and understand the safety precautions you have to take.

LCD monitors, likewise, tend to be worthless for parts (unless you like collecting a bunch of SMT components and such - I am not saying there's nothing there, just that it may be more trouble than it is worth) - if you have one lying around that you can tell just has a blown backlight, sometimes you can take some measurements and a bit of time (a few hours, usually) and repair the backlight, getting a nice LCD monitor for nearly free. I've done that a couple of times (once on a small laptop, and another time on a 15" LCD I bought on Ebay - both are still running good).

CD-ROM drives have some good components in them for robotics and other experimentation. Floppy drives, too - but you might want to hold on to and sell the 5.25 floppy drives (especially if they are older 360 or 720K drives - those are getting hard to find in the retro-computing marketplace) - while they sometimes have nice motors (oh, especially the old full-height drives), they are worth more to collectors and retro-computing users/enthusiasts than for parts. Any time I come across a 5.25 floppy drive, no matter the size, I buy it (same for 720-800K 3.5 drives - those are getting hard to find as well).

Oh - one other thing: check out the prices on Ebay for 386 motherboards - you may want to keep those! I imagine the 486 and early Pentiums are next in line for the collector...


Thanks for such a full answer cr0sh! I'd already decided not to dismantle my Sony external single speed caddy-loading CD-ROM drive, but I've loads of old CD drives (32x, so nothing worth keeping), dead hard drives, dead printers etc sitting in the office waiting for me to either come up with a use for them or throw them out :D

Thanks for such a full answer cr0sh!

I’m working on a novel…


Regarding the hard drives:

The motors that drive the platters are typically 3-phase motors that, while they can be driven in some manner externally (either via a special circuit, or more commonly by a microcontroller), generally can’t be driven as efficiently as you would want - and even if you got them running well, they typically spin as such high RPMs that you would need massive amounts of gearing to use them for anything (unless you are trying to spin a propeller for a plane, which I have heard people attempting to use them for). It’s basically a case of “too much effort for too little gain”, IMHO - unless you are trying to learn about how these motors work and how to write code to drive them, etc - which potentially could be useful for custom drive systems in R/C brushless motor controllers, etc.

However, there are some really nice and strong rare-earth magnets for the head positioner arm, plus there are other possible components you might be able to use. Finally, if you can strip everything off the casing of the drive, and get it down to just the alluminum billet casing - well, prices are up on alluminum somewhat (last I saw about a week back was around 80 cents (US) a pound) - and if you have enough of them - well, you could probably purchase an Arduino and some other parts with the proceeds!


I'd heard about magnets in HDDs and optical drives. I hadn't thought about trying to get the motors out of the HDDs though, it looked like it wouldn't be easy. I might find a use for some spinning platters though.

[edit]I hadn't thought about trying to get the motors out of the HDDs though, it looked like it wouldn't be easy.[/edit]

In older hard drives, 3-4 screws hold them in place. In newer drives, they tend to be nearly permanently mounted in place (I am not exactly sure how; probably a press fit with some kind of epoxy seal).

Broken hard drives' motors can be used as rotary encoders via a simple 4-opamp circuit. I've seen somewhere on the 'net someone build a dj consolle where an old hd platter was used as an "effects-turntable" (don't know the exact term...)

Ok I found it. It's on instructables:

Someone has also used an Arduino for something similar:


Thanks for the links mromani :slight_smile: