Need guidance on nema23 motor and powersupply

Using Arduino Motors, Mechanics, Power and CNC
1

Hello
I got myself an arduino uno and an motor shield rev3.
With this i want to drive an motor with these specs http://cnc4you.co.uk/resources/Stepper%20Motor%20Nema%2023%2060BYGH401-03%204Nm.pdf
In the bipolar series configuration.
However im wondering what kindoff powersupply i need. I have one 12v 5000ma, however since the Volt rating of the motor is 5,6V im afraid of burning it. My theory is that it takes 5,6v volt per channel which would make the total 12v however im not sure and would like confirmation before i burn something.
I have also disconnected the vin"jumper" on the underside of the board so that the power should be separate.

Anyone have any idea is it will work with a 12v supply or if ill burn the motor.

2

Basicly im trying to do the same thing as this guy.
http://forum.arduino.cc/index.php?topic=248862.0
However he doesnt mention if he reduced the voltage from his supply.

3

You need to read stepper motor basics.

That motor shield is quite unsuitable. The power supply is probably OK, but a higher voltage would probably be better.

...R

4

Big low impedance bipolar steppers like that are driven by current control, using
an industrial chopper driver costing $100's from a supply of 48V to 80V or so.
Probably not what you want.

What are you trying to do (include the numbers please, words like "big" or "fast"
aren't very informative when sizing a motor).

5

Thanks for the replies. I am making a automated zeovit reactor so basicly im going to spin a chamber of submerged rocks (about 1.2kg) back and forth a few times per day.

what would you recommend if i am doing a project as the guy in the link?

6

Why on earth use a stepper motor - this isn't a motion-control system, a geared DC
motor would be fine and much easier to drive. In fact a secondhand windscreen
wiper motor might be a perfect fit.

7

i guess i didnt take enough time to reasearch it proporely. I saw 2 threads about using steppers and the arduino (one used a smaller motor and one used the 4nm version). so i went with it and then ran headlong into problems.

8

Ok so i got it moving now. I changed the shield for a st-m5045 driver instead and that seems to have done the trick.
I am running the code below at the moment and the motor is wired according to the parallel setting detailed in the pdf in the first post.

However its still quite noisy while running less noisy when on a higher speed though. Is there anything i can do to reduce the noise? The guy i linked to seem to have gotten his motor more or less noiseless (however he is also running it on an arduino motor shield which i couldnt get to work)

Would it make a difference if i connected it in a series ionstead of a parallel connection or is there anything i can do settings wise och codewise to quiet it down?

The settings are at the moment (played around with em and it seems like this gives the most speed and the least noise)

400pulse/rev
4a
Full current

// Bounce.pde
// -- mode: C++ --
//
// Make a single stepper bounce from one limit to another
//
// Copyright (C) 2012 Mike McCauley
// $Id: Random.pde,v 1.1 2011/01/05 01:51:01 mikem Exp mikem $

#include <AccelStepper.h>

// Define a stepper and the pins it will use
AccelStepper stepper(2, 8, 9); // dir_a and dir_b pins used
const int pwmA = 8;
const int pwmB = 9;

void setup(){

Serial.begin(9600);
stepper.setMaxSpeed(7000);
stepper.setAcceleration(4000);
stepper.moveTo(5000);

pinMode(pwmA, OUTPUT);
pinMode(pwmB, OUTPUT);
digitalWrite(pwmA, HIGH);
digitalWrite(pwmB, HIGH);
// initialize the serial port:

}

void loop()
{
// If at the end of travel go to the other end
if (stepper.distanceToGo() == 0)
stepper.moveTo(-stepper.currentPosition());
stepper.run();

}

9

Should this line

AccelStepper stepper(2, 8, 9);

be

AccelStepper stepper(1, 8, 9);

if you are using a stepper driver that takes step and direction signals

Steppers tend to be noisy. They are usually quieter if you use microstepping but then you lose torque and precision.

If you want to experiment this simple stepper code does not use any libraries.

...R
Stepper motor basics

10

Or even

AccelStepper stepper(DRIVER, 8, 9);

using the relevant #define from AccelStepper.h ....

Microstepping reduces noise and increases torque and precision (a little).

The issue with torque is resonance - microstepping reduces resonance
significantly meaning the motor is less likely to stall at resonant speeds -
this is normally a bigger effect than the theoretical increase of torque due
to square wave v. sine wave drive in practice.

Mechanical damping can reduce resonance if you are forced to use full steps,
and in practice you need either microstepping or damping or both in any
high performance stepper system. Sometimes damping comes for free with the
mechanical load.

Higher performance stepper drives switch automatically from microstepping to
full stepping at high speeds, past the resonant frequencies, and some have
electrical damping via circuitry that senses resonance from the back-EMF signal.

It is true that microstepping can't give you much more precision unless the
motor is lightly loaded, and is limited by the tolerances of motor mechanical
construction. In general 1/16th steps is about the most you really need unless
acoustic noise is the main issue and you only need to move slowly.

As a datapoint I've recently been playing with the DRV8711 stepper driver
chip (very flexible/configurable driver) and a 2.5A NEMA17 motor (1.2 ohms).
3600rpm achievable (with fair amount of torque, 1/4 steps) from only 20V supply...
I suspect I could get higher with 1/8th steps, but I cannot generate them(*) fast enough!

The same motor, unloaded, stalls everytime on full steps when accelerated slowly.

That would move a reprap about 50cm/s

(*) Well I can, but not with a smooth acceleration profile.