Help with identifying stepper motors

[viroy]

I am trying to use 2 stepper motors i pulled from DVD burners and control them with Mach2/3. The problem is, i dont know what they are. can anyone please help identify them and reccomend a controller to use?
Thank you.

http://www.thebaerwolf.com/stepr/1.JPG
http://www.thebaerwolf.com/stepr/2.JPG
http://www.thebaerwolf.com/stepr/3.JPG
http://www.thebaerwolf.com/stepr/4.JPG

[viroy]

Or are they servos?
Actually I found a video of someone doing the EXACT same thing, but he did not have any info posted about them. I am hopefullay awaiting a response.
http://www.youtube.com/watch?v=STkjY-KBqgI

[chazmtu]

Hello,

They look like bipolar steppers. Bipolar steppers have four wires each pair for a different coil. They are the simplest electronically but hardest to drive. You can find some premade drivers, or try using dual H-bridge to control them. What are you planning to drive with them?

Chuck

[chazmtu]

Here's a dual h bridge. http://www.robotstore.com/store/prod...=62&catid=1633
each half drives a separate coil. you'll have to search for the proper sequence to get them to work right.

[viroy]

Im going to be pushing around a marker or other very lightweight objects.
I have ULN2003 chips i use for small unipolar motors but suppose these wont work with bi-polar? im looking for the smallest driver to control them with, and i would like to use mach

[viroy]

oh wow thats nice and small and sound exactly like what im looking for. have you ever used them before? are they easy to interface to mach?
are there by chance schematics available to build my own?

[viroy]

i also have a question about the motor...
are those 4 wires the only ones? or is there a ground/positive that is being used by the casing?
i dont have much experiance with bi-polar motors

[chazmtu]

Cool I've always wanted to try a plotter. Never found the time though.

have you ever used them before? are they easy to interface to mach? are there by chance schematics available to build my own?

you can find schematics, just do a google search for h-bridge. There are a ton of versions, they are all similar and you need a low current one. A diy version won't be so small though. I don't have any experience with mach but two h-bridges will have 4 inputs.

I've never used them before but this is how they work. Bipolar motors work by energizing each coil in different directions in a sequence. Each h-bridge gets a coil and the inputs allow each coil to be energized in either direction, and with a little trial and error you can find the right sequence for each motor direction, or find it online.

i also have a question about the motor... are those 4 wires the only ones? or is there a ground/positive that is being used by the casing? i don't have much experience with bi-polar motors

There should only be four wires. a good way to make sure is to get a multimeter and test for continuity between the case and each wire.

[viroy]

well I ordered that dual h-bridge on thursday and it just arrived! quick shipping!
Its going to take a while to solder it all up, but atleast its on a pcb

[viroy]

Ok I was successfull at assembling the h-bridge, I have also tested it with a generic 3v DC motor and it does work... However, I dont know how to connect it to those motors pictured above. You were saying I need to find the motor direction sequence, I am a bit of a noob so could you please explain?

The H-Bridge has 4 out leads, 2 for each motor. The motors I would like to control have 4 pins... do I connect all 4 leads to the motor?