<p>If it is 40&nbsp;W then it shouldn't matter what length it is. Note that the heater cartridge just contains a Nickel-Chrome wire-resistor (see image below for the construction), this resistor gives its heat to the metallic shell, the length of that shell shouldn't matter, it usually contains heat free/colder zones at the tip and root. Even if it is a 30&nbsp;W heater cartridge it should be able to get to temperature, it would just take longer.</p>

<p>If it is a 24&nbsp;V, 40&nbsp;W cartridge, operating at 12&nbsp;V, then the effective power would be <span class="math-container">$40[V] \times \frac{12[V]^2}{24[V]^2}=10 [W]$</span>. This might be too low to reach the temperature. It is best to check the resistance of the heater element with a multitester; it should be about 4 &ohm; for a 12&nbsp;V heater cartridge and about 14 &ohm; for a 24&nbsp;V heater cartridge.</p>

<p><a href="https://i.sstatic.net/ZQ3Ak.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZQ3Ak.png" alt="enter image description here"></a></p>

CC BY-SA 4.0
2020-05-27T14:46:05.567Z
2020-05-27T14:46:05.567Z
0scar
<p>Recently I had an issue with my heating cartridge, and I decided to change it.</p>

<p>For my Anet A8, I needed a <strong>12&nbsp;V 40&nbsp;W</strong> one. I ordered it but I received a <strong>15&nbsp;mm length</strong> instead of <strong>20&nbsp;mm length</strong> heater element, but as the characteristics where the same I thought that it should not be an issue!</p>

<p>When I finally tried it, it was not able to reach the commanded temperature. It's like <strong>175&nbsp;°C</strong> instead of <strong>195&nbsp;°C</strong>.</p>

<p>I don't understand why it's harder for the newer heating cartridge to reach the commanded temperature, is the length important even if it's the same power (12&nbsp;V and 40&nbsp;W) ?</p>

CC BY-SA 4.0
2020-05-27T12:15:08.337Z
Try to measure the resistance - does it have the expected 3-4 Ohms for a 40W 12V cartridge?
towe
CC BY-SA 4.0
2020-05-27T12:24:17.537Z
It might be the wrong cartridge
user77232
<hotend><anet-a8><heat-management>
Issue with the new heating cartridge of my 3D printer
Macronaute
# Issue with the new heating cartridge of my 3D printer

(Asked by: username_0 on 2020-05-27)

Recently I had an issue with my heating cartridge, and I decided to change it.

For my Anet A8, I needed a **12 V 40 W** one. I ordered it but I received a **15 mm length** instead of **20 mm length** heater element, but as the characteristics where the same I thought that it should not be an issue!

When I finally tried it, it was not able to reach the commanded temperature. It's like **175 °C** instead of **195 °C**.

I don't understand why it's harder for the newer heating cartridge to reach the commanded temperature, is the length important even if it's the same power (12 V and 40 W) ?

**Tags:** hotend, anet-a8, heat-management
> **Comments:**
> **username_1**: Try to measure the resistance - does it have the expected 3-4 Ohms for a 40W 12V cartridge?  
> **username_2**: It might be the wrong cartridge  

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## 1 answers

### Answer by username_3 on 2020-05-27. Score: 1

If it is 40 W then it shouldn't matter what length it is. Note that the heater cartridge just contains a Nickel-Chrome wire-resistor (see image below for the construction), this resistor gives its heat to the metallic shell, the length of that shell shouldn't matter, it usually contains heat free/colder zones at the tip and root. Even if it is a 30 W heater cartridge it should be able to get to temperature, it would just take longer.

If it is a 24 V, 40 W cartridge, operating at 12 V, then the effective power would be $40[V] \times \frac{12[V]^2}{24[V]^2}=10 [W]$. This might be too low to reach the temperature. It is best to check the resistance of the heater element with a multitester; it should be about 4 Ω for a 12 V heater cartridge and about 14 Ω for a 24 V heater cartridge.

[![enter image description here](https://i.sstatic.net/ZQ3Ak.png)](https://i.sstatic.net/ZQ3Ak.png)


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