Speeding Up Stepper Motor

[herring_fish]

I can’t get my stepper motor to go very fast. I have a very low mass to move but I need printer level speeds over an 8 foot slide. I am using a 1A wall wart so that might be the problem but right now, I’m just pushing a piece of tape around in a circle. How do I get it to go faster?

The simplified code and result of the different settings that I used are listed below and the hardware that I have is all listed below that.

        
#include <Stepper.h>

#define EN1_PIN 3
#define DIR1_PIN 12
#define EN2_PIN 11
#define DIR2_PIN 13

  const int stepsPerRevolution = 200;         // change this to fit the number of steps per revolution for your motor
                                                          // initialize the stepper //library on pins 12 and 13
  Stepper myStepper(stepsPerRevolution, DIR1_PIN, DIR2_PIN);

   void setup() {
         
      analogWrite(EN1_PIN, 255);               //>>>>>>With the other //motor I bumped the voltage up to 9 and set these to 10 - 66
      analogWrite(EN2_PIN, 255);               //>>>>>>per product support

      myStepper.setSpeed(150);                // Example sets the speed at //60 rpm. >>>>>>>My max is 150
                                                          //>>>>>>>after that, it //buzzes
       Serial.begin(9600);                          // initialize the serial port
                                                          // Change from divide-by-64 prescale on Timer 2 to divide by 8 to get
                                                          // 8-times faster PWM frequency (976 Hz --> 7.8 kHz). This should //prevent
                                                          // overcurrent conditions for steppers with high voltages and low //inductance.
       TCCR2B = _BV(CS21);                      //>>>>>>>Tried with and //without this line
      }

   void loop() {
                                                          // step one revolution in one direction:
                                                          // Serial.println("clockwise");
          myStepper.step(stepsPerRevolution);
 }

I have currently:
>Arduino Mega 2560 >Rugged Motor Driver >Breakout Board Shield (Assembled) >BNC Sensor Shield (Assembled) >RTC/EEPROM board

>57BYG084/1.8 Step Angle/12V/4 phase/0.6A per/100ohm(500VDC)/20ohm per/Class B/25mH Inductance per/Rotor inertia 38g.cm2/holding torque 6Kg.cm
Spec. Sheet http://www.jameco.com/Jameco/Product...2027.pdf

I also have this motor. I bought it because the driver board manufacture said that it was a good match for the price but I couldn't get it to work. I don’t know what I was doing wrong. That is when I pulled out the motor above.
>23KM-K213-P7V/ 1.8 DEG./COIL: 3VDC/1.8 ohms/2.6mH,TYPE: 2 Phase Uni-Polar, 6 lead STEPMOTOR-MPJA, Inc.

[doorknob]

What voltage are you running the motor at?

That motor has a relatively high inductance per winding. You will want a relatively high voltage to drive it with. The Rugged Motor Driver Shield has a maximum voltage rating of 30V, which may not be high enough to get the speed that you want.

You might be able to run the second motor that you listed at a good speed by using a lower voltage. How did you determine which wires to hook up to the driver? If you wired it incorrectly, that could explain why it failed to work.

[herring_fish]

I was using 12 volts for the bigger motor.

This is the motor that I bought.
1.8 DEG. STEPMOTOR-MPJA, Inc.
This the motor pin out.
http://www.mpja.com/download/17276ms.jpg
This the rugged motor driver shield.
Rugged Motor Driver
This is the board layout.
http://ruggedcircuits.com/assets/ima...0_D_layout.png

The other motor was hooked up this way:
I went from left to right on the layout.
J1+ was Red
J1- was Yellow
J2- was Orange
J2+was Blue
I didn’t use Black or White
I ran it at 9Volts
I just hooked it back up and it makes a plus (but doesn’t go anywhere) about very second and a half.

[doorknob]

12 volts is a very low voltage for the larger motor in this application. If you could increase that to 24 volts or more (up to 30 volts), the stepper motor should rotate faster, but it will probably not go anywhere near the maximum speed that you could get from it by using a higher voltage with a different controller (that can handle that higher voltage - it can probably take around 100 volts with a pulsed driver).

As for the smaller motor, it appears to me that you are hooking up the MPJA motor leads correctly. That smaller motor also needs a much higher voltage than 9 volts in this application. You could also increase that voltage to 24 volts or more, up to 30 volts.

Do you have, or can you borrow a 24 volt DC power supply (or a 30 volt supply) to test with?

Make sure that you are feeding the motor voltage through J4, and follow the directions in the Rugged Motor datasheet for external power supply input (for example, you must cut jumper J21 or else you will damage the Arduino board by applying more than 15 volts).

[herring_fish]

Thank you. Now I have hope again.

As for the smaller motor. How should I hook it up? You have the links to both the motor pin out and the board. Could you please give it a look. The guys at rugged told me to hook it up that way. They said that either of the pairs could be backward and that I could just reverse them around to get it right but I didn't have any luck.

[doorknob]

As for the smaller motor. How should I hook it up? You have the links to both the motor pin out and the board. Could you please give it a look. The guys at rugged told me to hook it up that way. They said that either of the pairs could be backward and that I could just reverse them around to get it right but I didn't have any luck.

Yes, you have hooked up the smaller motor properly.

If you have one of the pairs of wires connected "backward" the only result will be that the motor will turn in the opposite direction of the intended one. If that happens, you can either reverse the wiring of one of the pairs of wire, or else you can probably configure the direction of rotation in your Arduino software.

The smaller motor also needs a higher voltage. Your problem is most likely that 9 volts is nowhere near enough voltage to drive it properly in this application. Please review my post above for more info.

Good luck with it...

[herring_fish]

I can try to get access to 24 or 30 volts. I just tried 12 as well and the 9 volt setting. But like the bigger motor, the smaller motor should turn some right? Do you think that it is a defective motor?

[doorknob]

I can't say for certain, although you would think that if you were able to get some motion from the larger motor (that requires even more voltage than the smaller one), you might expect to get at least some motion from the smaller one.

Do you have (or have access to) an oscilloscope? Without probing the motor leads with an oscilloscope as they are being driven by the Rugged Motor Driver you are pretty much shooting in the dark.

One thing that you could try with the smaller motor just to verify that it does not have a defective coil is to disconnect it from the Rugged Motor Driver board and check continuity (low ohms reading) between the Red and Yellow wires, and then separately check for continuity between the Orange and Blue wires.

If those check out OK, you could try some more probing (to make sure that there is not a short circuit between the two windings or between either of the windings and the motor case).

If you're even more adventurous, you could put together a test circuit with some toggle switches (wired as an "H bridge") and a couple of D-cell batteries (wired in series to get 3 volts - for this test you will not be pulsing the voltage to the motor windings, so you probably should keep the test voltage to only 3 volts), and then attempt to cause the stepper to rotate by alternately energizing and de-energizing the windings in the pattern used to drive bipolar motors. It would be a good learning exercise as well as a diagnostic test. But if you're not comfortable with basic electronics you might find it a bit of a challenge, and you would need to take care to make sure that you don't set the switches in a way that shorts out the battery (I don't think that you'll do any major damage if you did, other than perhaps overheating some wires).

If you wanted to do that, take a look at any of the "intro to stepper motors" articles that you can find on the web. One of the standard ones is Jones on Stepping Motors, but that might be rough going if you have no prior electronics knowledge. If you do want to try it, read at least Chapter 1 and Chapter 3, paying particular attention to the Bipolar sections, for example:

Jones on Stepping Motor Types

and

Jones on Stepping Motor Control Circuits

[herring_fish]

If I go with the motor that works and go from 12 volts to 24 or 30, should it double the speed?

[doorknob]

Yes, I believe that if you double the voltage you should see double the speed.

[herring_fish]

Cool, then that is what I will do thanks a lot.

[herring_fish]

Well I found a Delta ADP-25HB AC adaptor. It says that it is:

30V=-=-=0.83A
That^^^is an approximation of the symbol linked below.
http://t0.gstatic.com/images?q=tbn:A...vfwN5bUC8xRngg

I also looked at several sights and finally found one that says that is was a 30VDC0.83A unit. So I guess that this is what I need? I sure hope so.

Oh! and when you say "...cut jumper J21...", do you mean drag something over the solder connector or cut it with a shape knight or something like that?