<h2>You seem to be looking for closed-loop stepper motors.</h2>
<p>Detection of stalling and skipping on open-loop (aka regular) steppers is possible - that's how Prusa mk3s+ finds home position without endstops*. But it is not reliable and precise - that's why Prusa firmware tests every axis a couple of times.</p>
<p>If quality matters, and you want to reliably detect stalls and skips during print, closed-loop motors are what you need. Per <a href="https://www.soyamotor.com/new_detail/nid/68655.html" rel="nofollow noreferrer">one of the manufacturers description</a>, they signal back to the controller what they are doing, so that controller can correct for skips and stalls:</p>
<blockquote>
<p>On the contrary, NEMA17 closed loop stepper motor feedback signal, according to the signal stepper motor driver to take the corresponding action measures or signal feedback to PLC, by PLC to determine the next step of the program.</p>
</blockquote>
<p>Open-loop steppers are much cheaper, so most manufacturers just massively over-spec their open-loop steppers to make them force their way thorough any obstacles like blobs of plastic, and not need to care about feedback signal, and pay for it. As far as I know, closed-loop steppers are not used in hobby or even entry business machines, cost of motors and controllers being prohibitive.</p>
<hr />
<p>* When the motor stalls, power draw changes. If your driver can monitor power draw, firmware can make educated guess about the stall.</p>

CC BY-SA 4.0
2023-12-06T10:41:09.027Z
Really great answer. Thank you. I just don't understand `that's how Prusa mk3s+ finds home position without endstops`, could you further explain that?
Bob Ortiz
CC BY-SA 4.0
2023-12-06T11:14:18.300Z
Also, do you know if step skipping could be detected using an encoder wheel as an error correction wheel, as mentioned here: https://3dprinting.stackexchange.com/q/21756/36802?
Bob Ortiz
CC BY-SA 4.0
2023-12-06T12:48:12.143Z
@BobOrtiz when the motor stalls, power draw changes. If your driver can monitor power draw, firmware can make educated guess about the stall.
Mołot
CC BY-SA 4.0
2023-12-04T17:27:56.050Z
2023-12-06T12:49:00.723Z
2023-12-06T12:49:00.723Z
Mołot
<p>Is there a method such as fetching data from to stepper motor drivers, that can <strong>automatically</strong> detect or count stepper motor skips or stepper motor stalling?</p>
<p>Preferably for a Creality Ender 3 V2 board v4.2.2, but any related information is welcome. If something like this exists, how does it work and what are common use cases or implementation of it?</p>
<p>The reason I am asking is because it is a performance indicator that could help to track or measure print consistency and quality.</p>

<stepper-driver><stepper><sensors>
Can stepper motor skipping or stalling be detected automatically?
Bob Ortiz
# Can stepper motor skipping or stalling be detected automatically?

(Asked by: username_0 on 2023-12-03)

Is there a method such as fetching data from to stepper motor drivers, that can **automatically** detect or count stepper motor skips or stepper motor stalling?

Preferably for a Creality Ender 3 V2 board v4.2.2, but any related information is welcome. If something like this exists, how does it work and what are common use cases or implementation of it?

The reason I am asking is because it is a performance indicator that could help to track or measure print consistency and quality.

**Tags:** stepper-driver, stepper, sensors


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## 1 answers

### Answer by username_1 on 2023-12-04. Score: 1 | Accepted answer

## You seem to be looking for closed-loop stepper motors.

Detection of stalling and skipping on open-loop (aka regular) steppers is possible - that's how Prusa mk3s+ finds home position without endstops\*. But it is not reliable and precise - that's why Prusa firmware tests every axis a couple of times.

If quality matters, and you want to reliably detect stalls and skips during print, closed-loop motors are what you need. Per [one of the manufacturers description](https://www.soyamotor.com/new_detail/nid/68655.html), they signal back to the controller what they are doing, so that controller can correct for skips and stalls:

> On the contrary, NEMA17 closed loop stepper motor feedback signal, according to the signal stepper motor driver to take the corresponding action measures or signal feedback to PLC, by PLC to determine the next step of the program.

Open-loop steppers are much cheaper, so most manufacturers just massively over-spec their open-loop steppers to make them force their way thorough any obstacles like blobs of plastic, and not need to care about feedback signal, and pay for it. As far as I know, closed-loop steppers are not used in hobby or even entry business machines, cost of motors and controllers being prohibitive.

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\* When the motor stalls, power draw changes. If your driver can monitor power draw, firmware can make educated guess about the stall.

> **Comments:**
> **username_0**: Really great answer. Thank you. I just don't understand `that's how Prusa mk3s+ finds home position without endstops`, could you further explain that?  
> **username_0**: Also, do you know if step skipping could be detected using an encoder wheel as an error correction wheel, as mentioned here: https://3dprinting.stackexchange.com/q/21756/36802?  
> **username_1**: @username_0 when the motor stalls, power draw changes. If your driver can monitor power draw, firmware can make educated guess about the stall.  

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