So I got my hands on an old flat bed scanner. Going to use it for a project. Need a way to interface arduino with the stepper motor.
The motor has this written on the side:
MOTOTECH
S35S6-3701
8BG0AA
There are 5 wires. Green, Blue, Red, Yellow, White.
Any help would be fantastic considering I have no idea what I'm doing. 
Have you Googled any or all of those numbers to see if you can get a datasheet for that motor?
What are the approximate dimensions of the motor?
If it is a small motor it may be possible to drive it with a ULN2003 in the same way as the popular 28byj-48 motors.
Some 5-wire motors are actually 6-wire motors with the two centre wires joined together. If so, and if you can separate them to give you access to all 6 wires you could control the motor as a bipolar motor and this Thread stepper motor basics may be useful. But it does NOT cover 5-wire motors.
...R
I have googled and apparently the motor is Mototech S35S6-3701. However, there were only about 5 results returned I think. I'm not home right now but from what I remember there was no sixth wire. I found this but gotta try when I get home. I own a 28byj-48 stepper motor and this one is only slightly bigger. I'll try to get a picture of both for scale. The reason I want to use this one and not the 28byj-48 is because this one is already installed in the scanner bed with the railing and everything.
If you still have the scanner intact, can't you trace the wires back to their controller board? That might be well known and be more easily handled by the Arduino than the motor (or even the morot 8) ) itself.
Yes I can connect everything back to the controller board. The board has a port to connect to the computer, power supply port for wall outlet, and a button to turn the scanner on and off. Is there any point in reconnecting it back together?
That's not quite what I meant, sorry I wasn't clear: I was wondering if there was a recognisable stepper controller chip on that board, and the Arduino may be able to talk to that chip. The chip might do the heavy lifting if you just send it some simple commands from the Arduino. Who knows, the chip might be well known and easy to access from Arduino.
But otoh there may be a proprietary chip on there....
Just reread my title....morot....damnit. I'll have to check when I get home. It was a big controller board with everything soldered on there so not sure how effective it will be. From what I've been finding on google no one has this type of motor and I'm most likely going to have to manually find out the phases and then buy a driver unless the 28byj-48 driver works for this which I doubt. Never manually found out the phases but I guess theres a first time for everything.
Ok so from what I've gathered I need to get a driver to even begin to test this stepper motor and determine which wires are which phase. This is a picture from google but looks very similar to my stepper motor. Do any of you fine gentlemen and ladies know a dirt cheap but effective driver that can work?
No I think you can "phase it out" by measuring the resistance across the wires and then applying power manually in the right sequence to pull it round. I did that once with a 4-wire job, can't find a reference to a 5-wire right now.
That might depend on yours being a real 5-wire or a 6-wire masquerading as 5-wires, see Robin2's reply at #1.
Don't get a driver until you identify the power requirements would be my advice.
What are you using to drive the 28byj-48 ?
...R
Always the first step is a multimeter set on resistance range to identify the windings.
5 wire motors should have one common wire with equal resistance to all the others.
Knowing the actual resistance value and the power rating of the motor allows a good
guess at a safe max current drive.
Robin2:
What are you using to drive the 28byj-48 ?...R
The driver which came with it on ebay. I think it was uln2003 or something.
MarkT:
Always the first step is a multimeter set on resistance range to identify the windings.5 wire motors should have one common wire with equal resistance to all the others.
Knowing the actual resistance value and the power rating of the motor allows a good
guess at a safe max current drive.
Does look like there are only 5 wires instead of 6. I have a voltmeter with resistance tester. How would I wire it? Don't stepper motors not have a ground? Do I need a battery?
Going to play with it a bit now that I'm home and I will let you know what I discover.
So I have a dt830b digital multimeter. I set the dial to 2000 (ohm symbol) and it shows 1 for every configuration I tried. Layout is as follows:
Green, space, Blue, Red, Yellow, White. I am attaching a picture of the stepper motor next to a 28byj-48 for scale.
The stepper motor has a connector and my pins from my multimeter are too fat to get in there so I taped them to wires. Will this be a problem? Could this be why I always get 1?
Edit: Ok so I took off the tape and am holding the wires together with my fingers. If I don't use my fingers its 1. If I use my fingers and white is set to positive, all but green show 075 instead of 1 when set to 2000ohm setting. Green shows 038.
So I tested some more with the 2000ohm setting and have the results.
White+Green=38
White+Blue=73
White+Red=73
White+Yellow=73
Yellow+Red=73
Yellow+Blue=73
Yellow+Green=38
Red+Green=38
Red+Blue=73
Blue+Green=38
Green is always about 38. Does this mean its the center tap and its actually a 6 wire stepper motor with 5 wires?
hunter2379:
its actually a 6 wire stepper motor with 5 wires?
I guess that's a good description of a 5-wire stepper. But if you can't separate the two wires to the coil centres it will always be a 5-wire motor.
...R
Any ideas how I would wire this and what driver would work?
Can you copy what you do with the 28byj-48 ?
...R
Robin2:
Can you copy what you do with the 28byj-48 ?...R
I haven't used the 28byj-48 yet. They are sitting in the baggies that they came in. The scanner motor would probably need 12v correct? If the wiring on the stepper motor doesn't match the driver I'm going to have to cut off the clip and mess with it aren't I?
I think it would be wise to get the the 28byj working first - at least you have full documentation for it.
If the existing plug on the scanner motor has female connectors you could make a temporary connection to a breadboard by sticking wires into the plug.
Before you cut off the connector make a very careful diagram of its wiring.
...R
I wasn't thinking of a breadboard. Going to try that with the uln2003 I guess. If the 5v don't work im going to need to find a way of getting 12v to it. What a project.