Hi everyone...its been a year or more....was busy in study, now got a graduation in computer applications.
i was working on a project, which requires a stepper motor, hopefully i got one in junkyard...there is a sticker saying STP-42D3016-03, 1.8° step, 18 ? and nothing else....
It has six wires, Orange, white, Yellow, Brown, Black and red.
if anyone knows the voltage to drive it, plz let me know, or how to figure out it. Also, i would like to know about X-Y card which can help, or i may be using L298N to drive it.
Thanks in advance. 
Well a multimeter will be needed to work out the windings, and measure the resistance
Since its a 6-wire motor you can drive it either unipolar or bipolar - 18ohms suggests unipolar.
Check the connections (each winding has a centre-tap for unipolar use) Find out if the
18 ohms is the whole of each winding or the half-winding value.
From the size an estimate of the power handling can be made, and thus the current can be
estimated. Shame the winding current rating isn't printed.
STP-42D3016-03 is customer model of SHINANO's stepper motor, only person would have spec is vendor. I guess this time he is out luck as well.
from above chart, voltage: ~8V ; current: ~0.5A (could be 14V/0.35A ?) is my best guess. wait MarkT or OP to confirm.
SHINANO's standard lead wire connection and color code
SHINANO use SST43 for motor size 42!
Well thanks a lot guys, both to MarkT and Sonnyyu...
now please suggest me a good driver for it..can i use ULN2004AN or L293DNE or L298DNE to drive it....?
Daniyal:
Well thanks a lot guys, both to MarkT and Sonnyyu...
now please suggest me a good driver for it..can i use ULN2004AN or L293DNE or L298DNE to drive it....?
As it's a 6-wire stepper, you can drive it in either unipolar mode using a ULN2803 (the ULN2004 is not ideal, because it is designed for at least 6V input), or bipolar mode using L293D or L298N. But you need to first measure the windings, to determine whether 18 ohms is the resistance of a whole winding or half a winding, and thereby calculate the current draw at whatever voltage you decide to use.
I have tried to give it a run via 9VA power supply using ULN2004AN, which resulted in some irregular steps(compiled example sketch of stepper_oneRevolution) and ended in frying the power supply adapter. But hopefully, both arduino and driver are fine, thanks to God.
Now as dc42 mentioned, I'll try it in bipolar mode with L293D or L298N.
I'm not a total noob(am a learner, instead), but I'm not getting what is meant by:
- Center tap(each winding has a center tap for unipolar use),
- How to figure out whether 18 ohms is the resistance of a whole winding or half a winding.
Daniyal:
I'm not a total noob(am a learner, instead), but I'm not getting what is meant by:
- Center tap(each winding has a center tap for unipolar use),
A coil has one connection at the start of the winding and one at the end of the winding. A centre tap is a third connection to the winding half way between the two. In the diagrams in reply #2, the left hand one shows coils without centre taps, and the other two show coils with centre taps.
Daniyal:
2. How to figure out whether 18 ohms is the resistance of a whole winding or half a winding.
Use a multimeter to measure the resistance between all the pairs of wires. If you get values of infinity, 18 ohms and 9 ohms, then 18 ohms is the resistance of the whole winding. If you get values of infinity, 36 ohms and 18 ohms, then 18 ohms is the resistance of half a winding, i.e. from the centre tap to one of the ends.
You need to know which it is before you choose a chip and a power supply to drive the motor.
For a pair [Brown-Black(center tap)-Orange], Brown-Orange gives 36?(36.5? specifically) and center taps (Brown-Black and Orange-Black) gives 18?(18.6? specifically) and same for the second pair [Red-White(center tap)-Yellow].
So this means 18? is the resistance of half-winding.
OK, now you can work out what sort of driver you need. For example:
Bipolar mode (H-bridge driver) with 12V drive: steady state current = 12V/36 ohms = 0.33A. An L293D will suffice, although it will get quite hot. Power supply needs to supply 0.66A.
Unipolar mode with 12V drive: steady state current = 12V/18 ohms = 0.67A. A ULN2803 may be sufficient if you drive each half winding from 2 of the drivers in the chip connected in parallel, but it will get rather hot. Power supply needs to supply 1.33A.
Note: I have ignored the voltage drop in the driver IC in these calculations. In practice, the L293D will drop about 3V, and the ULN2803 about 1.5V; so the current will be a little lower.
okez, so now i have used an H-Bridge(L293DNE) and tried running it via compiled example sketch of stepper_oneRevolution, but it is just vibrating...no revolution(s). Then i tried sketch of stepper_oneStepAtATime, which resulting in irregular steps....3 forward and 1 backwards. I reconnected wires in different fashion, so as to check if pairs could be different, altered the position of pin no(s). in code i.e. changed 8,9,10,11 to 8,9,11,10 etc. but result is same every time...
I'm using this reference(below one, four pins)http://arduino.cc/en/Reference/StepperBipolarCircuit, connected the 5th and 6th wires of stepper to VS(12volts) along with 8th pin of L293D. I have also rechecked to connect all the 4,5,12 and 13th pins of L293D to GND of Arduino and power supply.
Is it possible that stepper is culprit, or may be something left in connections...?
Please sort me out.
It will be a really big deal if i get this thing to work. Thanks.
Daniyal:
I'm using this reference(below one, four pins)http://arduino.cc/en/Reference/StepperBipolarCircuit, connected the 5th and 6th wires of stepper to VS(12volts) along with 8th pin of L293D.
If you are driving the stepper in bipolar mode, then DO NOT connect the centre tap connections to anything.
yeah am connecting in bi-polar....my mistake, I'm just stripping them away now. Would u please explain what will be the difference, in connecting them to VS and not connecting to anything, I would like to know.
If you are driving the stepper in bipolar mode, then DO NOT connect the centre tap connections to anything.
I have disconnected the center taps, but still the result is same 
You need to ensure each winding is driven from one of the H-bridges (don't cross wires over),
then you need to ensure you are driving with a valid sequence (such as A+ B+ A- B-).
I have previously figured out the pairs, which are matched exactly to this sheet(6 wires, color code 2)
But, i have also tried to reconnect wires in various sequences, just to check if another sequence could work fine, but nothing worked all sequences giving the same result.
I tried to check amperes from power supply, but I'm not able to get any successful result. I connected the leads of multimeter in series with the circuit, but multimeter shows zeros only (in ranges of 200?A to 200mA). While I checked the voltages (in parallel) which comes out to be 12 volts(without load) and 10.5(with load of circuit, when motor vibrates).
I think that the current is low as it is vibrating only, but then, the steps are there(via different sketch). The major problem is that the steps are irregular.
what diagnose can i do now..?
please help
Try writing a sketch to do steps very slowly, maybe 1 step every 10 seconds. Use your multimeter to measure the voltage across the A coil and the voltage across the B coil at each step. What you should find is:
-
All the time (once the sketch has run setup()), there should be 10.5V across BOTH windings.
-
On each attempt to step, the polarity of the voltage across ONE of the windings reverses. Which winding reverses changes alternately with each step. So the sequence is: A reverses; B reverses; A reverses; B reverses (at which point the polarities are back where they started); and so on.
ok, now i have used this:
#include <Stepper.h>
const int stepsPerRevolution = 200;
Stepper myStepper(stepsPerRevolution, 8,9,10,11);
int stepCount = 0; // number of steps the motor has taken
void setup()
{
Serial.begin(9600);
}
void loop()
{
myStepper.step(1);
stepCount++;
delay(10000);
}
But the result is same. The steps are in this sequence, which is same for the delay(500)
Forward, forward, backward, blank....and this continues for some loops, then stops and again begins after a short interval of time, like 30 seconds.
However, if I increases the value of 1 in myStepper.step(1), what changes should it bring?
Leave the step argument at 1. You need to measure the voltages across the coils at each step, as I suggested in my previous post. I suspect that one of the 8 drivers in the L293D has failed (or possibly, one of the input connections is bad), and that at one or two positions in the cycle, you are not getting 10.5V across both windings.
at out1(Brown wire-A) and out2(Red wire-B) the readings are:
0.7V (steps backward)
-0.72V (steps forward)
4.52V (steps forward)
10.7V (steps blank/none)
and again 0.7, -0.72 4.52 and 10.7 volts respectively.
at out3(Orange wire-A) and out4(Yellow wire-B), the reading are:
-4.69V (steps forward)
11.0V (steps blank)
6.65V (steps backward)
-6.9V (steps forward) respectively..and so on.
I have rechecked them after letting it run for half an hour, still the readings are same. Polarity is not reversing at any pair.
Daniyal:
at out1(Brown wire-A) and out2(Red wire-B) the readings are:
0.7V
-0.72V
4.52V
10.7Vand again 0.7, -0.72 4.52 and 10.7 volts respectively.
at out3(Orange wire-A) and out4(Yellow wire-B), the reading are:
6.6V
-10.5V
6.65V
4.47V respectively..and so on.
Those are not as they should be. Assuming you measured them with the +ve lead of the multimeter connected to out1 or out3, and the -ve lead connected to out2 or out4 respectively, then it sounds like either out2 is never going anywhere near +12V, or out1 is never going anwhere near ground. Similarly, out3 is never going anywhere near +12V or out4 is never going near ground. The most likely cause is blown drivers in the L293D. Unfortunately, in connecting the centre tap wires to +12V earlier, you will have overloaded it.