<p>Sadly this is a known-weak part on all Creality extruders of this design.</p>
<p>The tension arm is ABS plastic and will work fine for a few months, maybe a year and will then break around where the bearing is secured to the arm.</p>
<p>That equates to 5-10 kg of printing before the arm breaks.  Since its a higher pressure point, gluing will not succeed.</p>
<p>Your best option is to buy a replacement tension arm, in Aluminium.  There are many options on Aliexpess, though fit and finish can be a mixed bag.    I had to swipe some bolts from my original extruder-motor mount because the new one was short.</p>
<p>It is telling that Creality offer a metal one and not a plastic one, but sells new printers with just plastic ones.</p>

CC BY-SA 4.0
2023-03-30T04:15:19.413Z
2023-03-30T04:15:19.413Z
Criggie
<h4>Replacing the broken part</h4>
<p>You certainly don't need to buy a <em>whole</em> new extruder assembly, including a stepper motor.</p>
<p>You could just buy a new extruder mechanism, and upgrade from the  plastic<sup>1</sup> extruder, to a metal (aluminium(?)) extruder, such as the one (apparently) sold by Creality themselves, such as this<sup>2</sup>, <a href="https://store.creality.com/products/metal-extruder-kit-red" rel="nofollow noreferrer">Metal Extruder Kit (Red)</a>:</p>
<p><a href="https://i.sstatic.net/SV0nC.png" rel="nofollow noreferrer" title="Metal Extruder Kit (Red)"><img src="https://i.sstatic.net/SV0nC.png" alt="Metal Extruder Kit (Red)" title="Metal Extruder Kit (Red)" /></a></p>
<p>However, if you just need a certain piece of the extruder (from your photo, I can't tell which part is broken), you could search for that, although, it would probably be cheaper just to buy the whole thing.</p>
<p>As to the name of the particular part that is broken, again, it is difficult to tell from the photo which part is actually broken. If you could add an annotated photo or more explicitly show the broken part, then it would be easier to provide a name of the actual part.</p>
<p>That said, after re-reading your question, I <em>think</em> that you may be referring to the whole black assembly - along with the spring, brass knurled nut, pulley/bearing, and associated bolts - that sits on the stepper motor... if so, then that is the <strong>extruder</strong>.</p>
<h4>Identifying the parts of an extruder</h4>
<p>It can be confusing knowing exactly what the names of the <em>various parts of the extruder</em> are - seeing as the entire extruder assembly (including the hotend and stepper motor) is often referred to as the extruder, either individually or as a whole.</p>
<p>Here are a couple of images that map out the various parts of the extruder assembly:</p>
<p>From the excellent <a href="https://reprap.org/wiki/Category:Extruders" rel="nofollow noreferrer">RepRapWiki - Extruders</a></p>
<p><a href="https://i.sstatic.net/94ebr.png" rel="nofollow noreferrer" title="Annotated extruder diagram"><img src="https://i.sstatic.net/94ebr.png" alt="Annotated extruder diagram" title="Annotated extruder diagram" /></a></p>
<p>From <a href="https://www.matterhackers.com/articles/extruders-101:-a-crash-course-on-an-essential-component-of-your-3d-printer" rel="nofollow noreferrer">Extruders 101: A crash course on an essential component of your 3D printer</a></p>
<p><a href="https://i.sstatic.net/lnAYp.jpg" rel="nofollow noreferrer" title="Annotated extruder photo"><img src="https://i.sstatic.net/lnAYp.jpg" alt="Annotated extruder photo" title="Annotated extruder photo" /></a></p>
<p>Note that:</p>
<ul>
<li>The <em>hobbed bolt</em>, is sometimes referred to as the <em>knurled bolt</em> or <em>knurled nut</em></li>
<li>The idler wheel is (generally) just a bearing</li>
</ul>
<hr />
<h4>Footnotes</h4>
<p><sup>1</sup> As <a href="https://3dprinting.stackexchange.com/questions/20664/replacing-and-identification-of-a-broken-piece-of-the-extruder/20665?noredirect=1#comment39442_20665">confirmed in the comments</a>, the extruder that comes with the non-pro version of the Ender 3 is plastic.</p>
<p><sup>2</sup> I'm not recommending this seller, nor am I sure that they are genuine Creality parts... this is just an example for what you need to be looking for.</p>

CC BY-SA 4.0
2023-03-09T15:25:08.397Z
If you have access to a printer in working condition, you can even print these parts.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2023-03-11T05:36:07.833Z
thank you for the advice.  I will do some research on replacement extruders.  I'm likely going to go to creality directly.  thanks again.  

RE: what broke? 

the metal "guide wheel" that hugs the filament as its pushed through, the plate beneath it broke.  I dropped a socket wrench on it. -- it's just sitting there in the photo, but it's not doing it job. I thought the "extruder" was the hot end.
Glenn Ferrie
CC BY-SA 4.0
2023-03-11T10:06:22.103Z
@GlennFerrie - Not quite. While the hotend does indeed actually extrude the filament, it is generally referred to as the hotend, which make up part of the overall extruder. It's confusing, I know. I've added a couple of images to help explain what the various parts are called. However, there may be better annotated images out there.
Greenonline
CC BY-SA 4.0
2023-03-20T00:59:14.080Z
from your image about the "bearing" broke off.  I am going to order another one AND try to repair it... wish me luck
Glenn Ferrie
CC BY-SA 4.0
2023-03-20T06:18:52.620Z
@GlennFerrie - Ah, good luck! One question, is your original extruder made of plastic, or is it already a metal of some kind? The bits that are red in my first photo... It would be interesting to know.
Greenonline
CC BY-SA 4.0
2023-03-28T02:50:46.567Z
@Greenonline Yes. It was a plastic extruder. the one that shipped with the Ender 3 (not pro)... I was able to repair it.  I remove the screw / washer / wheel then fixed the base underneath. I installed the red metal replacement but I am keeping the repaired part ... because I'm a hoarder. :-)
Glenn Ferrie
CC BY-SA 4.0
2023-03-28T07:19:18.497Z
@GlennFerrie - excellent! :-)
Greenonline
CC BY-SA 4.0
2023-03-09T10:29:18.960Z
2023-03-28T07:25:55.977Z
2023-03-28T07:25:55.977Z
Greenonline
<p>I've an Ender 3 and a piece broke.</p>
<p>The part that is broken is on top of the Z stepper motor that guides the filament to the extruder.</p>
<p>The metal &quot;guide wheel&quot; that hugs the filament as its pushed through, the plate beneath it broke. I dropped a socket wrench on it. -- it's just sitting there in the photo, but it's not doing it job.</p>
<p>Do I have to replace the whole stepper motor or can I just get the feeder thing that sits on top of the motor?</p>
<p><a href="https://i.sstatic.net/ouABu.jpg" rel="nofollow noreferrer" title="This thing..."><img src="https://i.sstatic.net/ouABu.jpg" alt="This thing..." title="This thing..." /></a></p>
<p>I don't know what it's called so it's tough to search for</p>

CC BY-SA 4.0
2023-03-09T08:18:08.613Z
I might be wrong but... This looks like a generic extruder mechanism - You can find them for pennies, made from aluminium, on eBay or AliExpress. I must admit that I can't quite see which part is broken. Could you maybe annotate the photo to point out the part that is broken and add that to your post..? Or add a photo taken from another angle? Or add a photo of an unbroken Creality extruder for comparison. FWIW, here is [an answer](https://3dprinting.stackexchange.com/a/9943/4762) that has a photo of the parts of a generic MK8 extruder, it may help you.
Greenonline
<creality-ender-3><extruder>
Replacing (and identification) of a broken piece of the extruder
Glenn Ferrie
# Replacing (and identification) of a broken piece of the extruder

(Asked by: username_0 on 2023-03-09)

I've an Ender 3 and a piece broke.

The part that is broken is on top of the Z stepper motor that guides the filament to the extruder.

The metal "guide wheel" that hugs the filament as its pushed through, the plate beneath it broke. I dropped a socket wrench on it. -- it's just sitting there in the photo, but it's not doing it job.

Do I have to replace the whole stepper motor or can I just get the feeder thing that sits on top of the motor?

[![This thing...](https://i.sstatic.net/ouABu.jpg "This thing...")](https://i.sstatic.net/ouABu.jpg "This thing...")

I don't know what it's called so it's tough to search for

**Tags:** creality-ender-3, extruder
> **Comments:**
> **username_1**: I might be wrong but... This looks like a generic extruder mechanism - You can find them for pennies, made from aluminium, on eBay or AliExpress. I must admit that I can't quite see which part is broken. Could you maybe annotate the photo to point out the part that is broken and add that to your post..? Or add a photo taken from another angle? Or add a photo of an unbroken Creality extruder for comparison. FWIW, here is [an answer](https://3dprinting.stackexchange.com/a/9943/4762) that has a photo of the parts of a generic MK8 extruder, it may help you.  

---

## 2 answers

### Answer by username_1 on 2023-03-09. Score: 5 | Accepted answer

#### Replacing the broken part

You certainly don't need to buy a *whole* new extruder assembly, including a stepper motor.

You could just buy a new extruder mechanism, and upgrade from the plastic1 extruder, to a metal (aluminium(?)) extruder, such as the one (apparently) sold by Creality themselves, such as this2, [Metal Extruder Kit (Red)](https://store.creality.com/products/metal-extruder-kit-red):

[![Metal Extruder Kit (Red)](https://i.sstatic.net/SV0nC.png "Metal Extruder Kit (Red)")](https://i.sstatic.net/SV0nC.png "Metal Extruder Kit (Red)")

However, if you just need a certain piece of the extruder (from your photo, I can't tell which part is broken), you could search for that, although, it would probably be cheaper just to buy the whole thing.

As to the name of the particular part that is broken, again, it is difficult to tell from the photo which part is actually broken. If you could add an annotated photo or more explicitly show the broken part, then it would be easier to provide a name of the actual part.

That said, after re-reading your question, I *think* that you may be referring to the whole black assembly - along with the spring, brass knurled nut, pulley/bearing, and associated bolts - that sits on the stepper motor... if so, then that is the **extruder**.

#### Identifying the parts of an extruder

It can be confusing knowing exactly what the names of the *various parts of the extruder* are - seeing as the entire extruder assembly (including the hotend and stepper motor) is often referred to as the extruder, either individually or as a whole.

Here are a couple of images that map out the various parts of the extruder assembly:

From the excellent [RepRapWiki - Extruders](https://reprap.org/wiki/Category:Extruders)

[![Annotated extruder diagram](https://i.sstatic.net/94ebr.png "Annotated extruder diagram")](https://i.sstatic.net/94ebr.png "Annotated extruder diagram")

From [Extruders 101: A crash course on an essential component of your 3D printer](https://www.matterhackers.com/articles/extruders-101:-a-crash-course-on-an-essential-component-of-your-3d-printer)

[![Annotated extruder photo](https://i.sstatic.net/lnAYp.jpg "Annotated extruder photo")](https://i.sstatic.net/lnAYp.jpg "Annotated extruder photo")

Note that:

* The *hobbed bolt*, is sometimes referred to as the *knurled bolt* or *knurled nut*
* The idler wheel is (generally) just a bearing

---

#### Footnotes

1 As [confirmed in the comments](https://3dprinting.stackexchange.com/questions/20664/replacing-and-identification-of-a-broken-piece-of-the-extruder/20665?noredirect=1#comment39442_20665), the extruder that comes with the non-pro version of the Ender 3 is plastic.

2 I'm not recommending this seller, nor am I sure that they are genuine Creality parts... this is just an example for what you need to be looking for.

> **Comments:**
> **username_3**: If you have access to a printer in working condition, you can even print these parts.  
> **username_0**: thank you for the advice.  I will do some research on replacement extruders.  I'm likely going to go to creality directly.  thanks again.    RE: what broke?   the metal "guide wheel" that hugs the filament as its pushed through, the plate beneath it broke.  I dropped a socket wrench on it. -- it's just sitting there in the photo, but it's not doing it job. I thought the "extruder" was the hot end.  
> **username_1**: @GlennFerrie - Not quite. While the hotend does indeed actually extrude the filament, it is generally referred to as the hotend, which make up part of the overall extruder. It's confusing, I know. I've added a couple of images to help explain what the various parts are called. However, there may be better annotated images out there.  
> **username_0**: from your image about the "bearing" broke off.  I am going to order another one AND try to repair it... wish me luck  
> **username_1**: @GlennFerrie - Ah, good luck! One question, is your original extruder made of plastic, or is it already a metal of some kind? The bits that are red in my first photo... It would be interesting to know.  
> **username_0**: @Greenonline Yes. It was a plastic extruder. the one that shipped with the Ender 3 (not pro)... I was able to repair it.  I remove the screw / washer / wheel then fixed the base underneath. I installed the red metal replacement but I am keeping the repaired part ... because I'm a hoarder. :-)  
> **username_1**: @GlennFerrie - excellent! :-)  

---

### Answer by username_2 on 2023-03-30. Score: 0

Sadly this is a known-weak part on all Creality extruders of this design.

The tension arm is ABS plastic and will work fine for a few months, maybe a year and will then break around where the bearing is secured to the arm.

That equates to 5-10 kg of printing before the arm breaks. Since its a higher pressure point, gluing will not succeed.

Your best option is to buy a replacement tension arm, in Aluminium. There are many options on Aliexpess, though fit and finish can be a mixed bag. I had to swipe some bolts from my original extruder-motor mount because the new one was short.

It is telling that Creality offer a metal one and not a plastic one, but sells new printers with just plastic ones.


---

