Connecting A4983 to a Nema23 motor

Evening gents,

Stepping into new territory here so please be gentel…

Building a CNC machine, and using the following electronics.

3x Pololu A4983 stepper motor driver, Carrier with voltage regulators,
3x Nema 23 motor:
Step/Deg 1.8
Rated Votage 4V
Current/Phase 2A
1x Aduino Mega.
Now I am strarting to connect everything up, read through the A4983 data sheet, but don’t want to end up toasting a board.

Is there any advice on this setup or something that I should or shouldn’t do?

Back again,
Had a look at the resourse tab,but I am still stuck. Sure this is a easy as pie, but can someone shed some light for me.
I think I am fine with the digital outputs to the arduino.
But how do I connect the motor. Do I need any other components or do I connect the motor only to the Driver?
Stepper motor has 8 wires:
two for each coil, from the motor driver I can see connections for 2 coils. Then still power, just a bit confusing. he he.
Diagram of motor. … -2808S.pdf



It looks like those eight wires are intended to allow you multiple configurations. You want the bipolar(s) one to get a bipolar motor with the pairs of coils in series. Connect A’ to C’ and use A and C as one of your coils, and then connect B’ to D’ and use B and D as your other coil.

If you want to get past about an amp per coil, you’ll have to do some heat sinking to keep the drivers from overheating.

- Jan

Thank you Jan,

I actually did manage to figure out the correct connection for the Bipolar (S) connection of the motors to the stepper motor. Advice for a heat sink on the chip is appreciated and this is something that I will definitely look into.

Looking at the Motor Spec sheet the rated voltage is 4V and the Inductance is up to 6.4mH when connected in Bipolar (S).
What would the voltage on the power supply be that I should connect to each Vmot and how do I calculate it? My understanding was that each motor used 4v and I was planning on using a ATX power supply.

Someone suggested a 80v but 48v would do that seemed a bit much to me, and I noted that the motor driver stated (8 – 35 V).

Thank you

You can get some double-sided tape made for mounting heat sinks or thermal epoxy. For the voltage question, I would use whatever is convenient that fits the motor driver range. If you’re using a computer power supply, 12V should be fine.

- Jan

Managed to cut some small heatsinks from a old CPU heatsink, waiting for the tape then I will be on my way.

Found a thread where someone is doing the same as myself, and could look at his schematics. I build a CNC, his is a reprap, but the Arduino controller is flashed with the same GCode interpretor.

I did wire the board up in the same manner, and ran a test. Got the motor to move backwards and forwards, but cautions of the temp I kept monitoring the chip on the A4983 with my finger. High tech measurements I know.
This became fairly hot after 2-3 seconds, where I disconnected the power.

Adhering on the side of caution,
Firstly is this connections correct?

Then whats the best/safest to run the controller at for the setup. Still a bit confused on the step size that I should select and the current limiting that I probably should configure on this board. Any advice.

This setup will drive a small CNC table that I built on the below design. … g-Machine/

Once the heat sink is on each chip I will mount a small pc fan to keep it cool.

PS. Followed your advice and all runs off a 12v feed.

If the motor is running the way you want it to, you probably have the right connections. The step size is up to you and your application; at some point, you won’t really get meaningful steps, and it will just be a hassle making faster pulses and keeping track of your position counts.

- Jan