<p>You are correct, from the connector, only 4 wires are used.</p>
<p>Stepper motors are DC motors that usually have multiple coils, organized in groups called &quot;phases&quot;. The stepper in question has two phases, energizing each phase in sequence, the motor will rotate, one step at a time.</p>
<p>Note that is doesn't matter how these phases are called, as long as you pair the correct coils. In order to find two wires of the same coil, just short circuit 2 of the wired, if you feel resistance, then the two wires are from the same coil, if not, try to connect a different set. You could use a multimeter as well. Once you have identified the 2 pairs of wires it does not matter if they are A or B, just connect the pair correctly to the connector on the controller board, usually this is seen on the silk screen on the board, otherwise, look up the documentation for the board. If the stepper runs in the wrong direction, switch direction in firmware or flip the connector 180° on the board or rewire the connector on the board side.</p>

CC BY-SA 4.0
2024-07-05T09:54:19.767Z
2024-07-05T09:54:19.767Z
0scar
<p>Does the fact that a given stepper motor used in a 3D printer is &quot;NEMA 17&quot; and uses 4 out of 6 pins (1, 3, 4, and 6) reliably imply anything about the functionality of those 4 pins (at the motor end), insofar as polarities A/+ and B/- of coils 1 and 2 are concerned?</p>
<p>I'm trying to replace the stock controller board in my Anet ET4+ with a BTT SKR Mini E3 v3.0, and going crazy trying to identify the pins on the stepper motor's 6-pin connector (which uses only 4 of them).</p>
<p>The specific part number on the steppers is 42SHDC3025-24B</p>
<p>I've spent days trying to confidently nail down the pin functions, and it seems like every document I've found has had a different opinion. I've literally found 3 radically different opinions:</p>
<pre><code>    2B    1A 2A    1B
    1+    2+ 1-    2-
    A+    A- B+    B-
</code></pre>
<p>Here's an example:</p>
<p><a href="https://i.sstatic.net/LhHTgqFd.webp" rel="nofollow noreferrer"><img src="https://i.sstatic.net/LhHTgqFd.webp" alt="probably-incorrect pinout diagram for Anet stepper motor" /></a></p>

<stepper><wiring>
Anet stepper (42SHDC3025-24B) pinout?
Bitbang3r
# Anet stepper (42SHDC3025-24B) pinout?

(Asked by: username_0 on 2024-07-05)

Does the fact that a given stepper motor used in a 3D printer is "NEMA 17" and uses 4 out of 6 pins (1, 3, 4, and 6) reliably imply anything about the functionality of those 4 pins (at the motor end), insofar as polarities A/+ and B/- of coils 1 and 2 are concerned?

I'm trying to replace the stock controller board in my Anet ET4+ with a BTT SKR Mini E3 v3.0, and going crazy trying to identify the pins on the stepper motor's 6-pin connector (which uses only 4 of them).

The specific part number on the steppers is 42SHDC3025-24B

I've spent days trying to confidently nail down the pin functions, and it seems like every document I've found has had a different opinion. I've literally found 3 radically different opinions:

```
    2B    1A 2A    1B
    1+    2+ 1-    2-
    A+    A- B+    B-

```

Here's an example:

[![probably-incorrect pinout diagram for Anet stepper motor](https://i.sstatic.net/LhHTgqFd.webp)](https://i.sstatic.net/LhHTgqFd.webp)

**Tags:** stepper, wiring


---

## 1 answers

### Answer by username_1 on 2024-07-05. Score: 0

You are correct, from the connector, only 4 wires are used.

Stepper motors are DC motors that usually have multiple coils, organized in groups called "phases". The stepper in question has two phases, energizing each phase in sequence, the motor will rotate, one step at a time.

Note that is doesn't matter how these phases are called, as long as you pair the correct coils. In order to find two wires of the same coil, just short circuit 2 of the wired, if you feel resistance, then the two wires are from the same coil, if not, try to connect a different set. You could use a multimeter as well. Once you have identified the 2 pairs of wires it does not matter if they are A or B, just connect the pair correctly to the connector on the controller board, usually this is seen on the silk screen on the board, otherwise, look up the documentation for the board. If the stepper runs in the wrong direction, switch direction in firmware or flip the connector 180° on the board or rewire the connector on the board side.


---

