Controller for Ebay-Bought Sanyo Denki Stepper Motor

Discussion in 'The Projects Forum' started by ukee1593, Jun 24, 2012.

  1. ukee1593

    Thread Starter New Member

    Jun 24, 2012
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    Hi folks, I'm fairly new to electronics so please be patient with me ...

    I'm looking at buying a stepper motor as a good way to learn more about controller circuits and similar.

    I have found this: Sanyo Denki stepper motor cheap on ebay and thought it would be a good unit to experiment with ... and in the future use to build a home-made CNC machine.

    However I have read that certain Sanyo Denki steppers require a special controller chip in order to work ... and cannot be driven from a standard controller. My question is: would I be able to run that particular stepper motor with a PIC or AVR microprocessor and a H-Bridge amplifier??

    The diagrams on the ebay listing look like it is a standard stepper and should work ... I'd just like to be sure before I blow $20 on a stepper.

    Research I have already done: http://ww1.microchip.com/downloads/en/devicedoc/41233a.pdf basic research on driving stepper motors with simple microcontrollers

    http://www.instructables.com/id/Drive-a-Stepper-Motor-with-an-AVR-Microprocessor/?ALLSTEPS

    Thanks in advance


    Luke
     
  2. Sparky49

    Active Member

    Jul 16, 2011
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    417
    Hi Luke, welcome to the forums! :)

    I've not had any experience with the motor you are talking about, but a good thing to do would be to google its part number and look for data sheets on it. If it does need a specific driver ic, then it should have it in the datasheet.

    I'll see if I can find anything for you,

    Sparky
     
  3. Sparky49

    Active Member

    Jul 16, 2011
    834
    417
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
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    If the motor has only 4 wires you will be forced to use a Bipolar stepper driver.

    If it has 5,6 or 8 wires you can use any type of stepper controller, Unipolar or Bipolar.
     
  5. ukee1593

    Thread Starter New Member

    Jun 24, 2012
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    Thanks very much for taking a look at this for me.

    Now to just get onto ordering the stepper so I can start playing with it ;) ... I can't wait!!

    Cheers,




    Luke
     
  6. Sharpen047

    Member

    Apr 19, 2012
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  7. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    If you just want to play with a stepper, why not find an old ink jet printer? they have small step motors in them that won't cost as much. The motor you found on E-bay would be very marginal in power for even a small CNC. Most use a NEMA size 23 and that is a NEMA 17 size.
     
  8. ukee1593

    Thread Starter New Member

    Jun 24, 2012
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    ^^ I have been asking around for some old inkjet printers, but I haven't had any luck.

    If I find that this specific stepper is too small to be of any use in a CNC machine, I have some other ideas that I could use it in ... so I won't be left with something I cannot use.

    ++ The oldest inkjet I own is only about 3-4 years old, and still works. A friend has also advised me that the newer inkjet printers cut costs by using a standard brushed DC motor instead of steppers these days ... so pulling apart a new inkjet might not be very useful if scrounging for stepper motors!
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    As Shortbus mentioned, NEMA 17 size steppers are really too small to be practical for CNCs; they have comparatively meager torque. You might make them work, but you will be forced to run your setup very, very slowly. If you want any kind of speed out of it, use NEMA 23 or larger stepper motors.
     
  10. AlainB

    Active Member

    Apr 12, 2009
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    Hi,

    I would say that you can build a small CNC machine with Nema 17 motors. It would be very good for PCB drilling and small milling on soft material. Not so fast but it could be accurate.

    It is certainly a good and not expensive start.

    If you did not order your motor yet, here is one that I suggest you to buy instead. Less strong than the one on EBay but will be easily driven using a ULN2803A as power stage. It is the SM4202, a unipolars motor at 4.99$:

    http://www.abra-electronics.com/products/Bipolar-and-Unipolar-Stepper-Motors.html?setCurrencyId=1

    Here is some of these motors in action in one of my "yet to be finished (one day) project":

    http://www.youtube.com/watch?v=BAvMMzYG5r4


    The driver here is the same design as in the video but built on a copper strips protoboard. It will work well with the motor that I suggested but will not work well with the Ebay one. ULN2803A is limited to .5 amp. Note, if you want to build it, that the red X indicate where the copper strips must be cut. 4070 and 4027 chips are Ok to use instead of 14070 and 14027.

    The logic stage design, using 4070 and 4027 (or 14070 and 14027) chips is not from me. It is a design that I found on the web many years ago. It provide a full step sequences.

    [​IMG]

    [​IMG]
     
    Last edited: Jul 8, 2012
  11. ukee1593

    Thread Starter New Member

    Jun 24, 2012
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    0
    ^^ Thanks AlainB for posting the controller designs that you are using for your CNC. Those motors look quite good for such a reasonable price tag!! I'll keep an eye on your Youtube so I can see how your CNC works out. ++ I understand your timeframe of finishing "one day" ... I too am not expecting to get my CNC project built for at least 6 months!!

    I'm planning on building a stack of H-Bridges out of MOSFETs to drive the steppers so the extra current draw of the Sanyo Steppers should not be a problem. (I'm planning on using IRF 9640 for the high side, and IRF 640N for the low side).

    Instead of jumping straight into a huge timber/metal CNC as a first project I might start off with building a small CNC for routing/drilling PCBs for other electronics projects. I also took a look at the NEMA 23 size steppers on Ebay, but they were a lot more expensive ($50 per stepper vs $15) ... so for the moment I'll be starting off with these smaller units.
     
  12. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    You might want to check out this guy's forum - http://www.microcarve.com/forum/
    he also posts on CNCZone.com. John has a couple of real nice easy CNC machines that he gives the design away for or he'll sell you one ready to run. They are one of the best and easiest machines I've seen.
     
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