Stepper Motor/Driver Carrier Questions

I bought the Pololu “stepper Motor: Bipolar, 200 Steps/Rev, 28×45mm, 4.5V, 0.67 A/Phase” and the “A4988 stepper motor driver carrier with voltage regulators”, wired it together and nothing happened. I then had other things to do and let the project go for over a year. I’m determined to make this work and I see there is no way to control this particular stepper motor like other motors with the program downloads available on this site. How is this stepper motor stopped/started? Can the amount of rotation be altered by a control panel? Thanks for any help.

If you follow the wiring directions and advice given here pololu.com/product/1182 there is absolutely no reason for the circuit not to work. Of course, you will need a microcontroller, or a couple of switches, to properly activate the DIR and STEP inputs of the motor driver.

I have the A4988 stepper motor driver carrier with voltage regulators which is different from the driver carrier in your link. I have never programmed or used Arduino and much of the operational technology is new to me. Does the DIR/STEP receive commands via wires from a Micro Maestro 6-Channel USB Servo Controller or a Mini Maestro 12-Channel USB Servo Controller or a Pololu Jrk 21v3 USB Motor Controller with Feedback ? It would be so much easier if there was a diagram entailing the components and how they were connected. The film of the home built router/lathe? was helpful in that the cooling fan situation was displayed and a Radio Shack Enercell™ Universal 300mA AC Adapter was used which is what I use although the voltage outputs aren’t accurate.

If you have this motor driver pololu.com/product/1183 then follow the wiring instructions given on that page.

If I understand your last post correctly, you are attempting to use a 300mA battery charger as a motor power supply. This is totally inadequate. The motor driver requires a minimum of 8 V and the motor requires a maximum of about 1.4 amperes (both windings are activated in full step mode and each winding can draw up to 0.67 amperes). You can, however, set the current limit to lower the motor current and thus lower the current required from the power supply.

Finally, none of these products is intended for use with the motor driver: [quote]Micro Maestro 6-Channel USB Servo Controller or a Mini Maestro 12-Channel USB Servo Controller or a Pololu Jrk 21v3 USB Motor Controller with Feedback[/quote] Instead you should use a programmable microcontroller such as the Orangutan from Pololu, an Arduino or a Basic Stamp. There is lots of info on the web on how to do that, for example forum.arduino.cc/index.php?topic=133894.0

So no diagram with all the bells and whistles. The step down transformer, or, the Radio Shack adapter will provide 1.5 to 12 volts @ 300mA, I guess. I read very carefully a warning about exceeding (500 mA??) when using the particular stepper motor in my possession. It will ruin the motor, warned the text. But that is the problem with standing at the threshold of understanding the stepper motor and all the components used to operate it and then dropping it and doing something else for over a year and returning to it with only a fuzzy memory. But I recall choosing my Radio Shack adapter very carefully to ensure I remained within the safe limit of voltage and amperage. It would be nice if there was a diagram or photos of my stepper motor and the necessary components assembled to make it work and with all the values listed.

Jim,
I found it.

Question: “I want to control a 3.9 V, 600 mA bipolar stepper motor like this, but your A4988 stepper motor driver carrier has a minimum operating voltage of 8 V. Can I use this driver without damaging the stepper motor?”

Answer: “Yes. To avoid damaging your stepper motor, you want to avoid exceeding the rated current, which is 600 mA in this instance.”

No, no bells and whistles. Check online tutorials for that, but beware that many are misleading, just plain awful or completely wrong.

Hobbyist suppliers like Pololu, SparkFun, etc. are generally aimed at people who are willing to research and experiment on their own. If available locally, you could also join a makers or robotics club and get help from group members. Expect to burn a few things up – I still do that from time to time, despite having over 40 years of experience with electronics.

Stepping motors are not instantly ruined by allowing too much current to flow through the windings, but they will overheat and can be destroyed after a time. Many stepping motors are intended to run hot (sometimes too hot to touch) but if you make sure that the average winding current does not exceed the manufacturer’s rated maximum, it will survive for very long periods of time.

After reading what you just wrote I am reminded of the adage, “Go strong or go home!” If you don’t have what I asked then why bother responding at all? You said something that would clearly damage my stepper motor. Then you say that you burn things up after 40 years in electronics. Pololu/SparkFun doesn’t work as you said. If Pololu or SparkFun would provide a schematic or instructions or diagrams explaining how to assemble a stepper motor that works then I would become encouraged and buy several more stepper motors from Pololu. If someone says “research it” or “look it up on the internet” then that indicates that they do not know how something works. I am not interested in your failures.

Well, you certainly took that the wrong way.