<p>Thermal runaway occurs when the hotend is on, but the temperature does not reach the desired temperature. This happens when printing faster than the hotend can heat the filament.
To be sure that this is really the case, keep an eye on the temperature during layer 2 and 3.
Lower the print speed to fix your issue. I am impressed that you achieve 600mm/s at all as it is well beyond the max speed of an Ender3 v2, so don't be surprised if you have to slow down though.</p>

CC BY-SA 4.0
2024-12-09T19:53:11.693Z
600mm is the filament max. I didn't go over 250. The build plate lost steps at that speed too. I just went back to the 50mm default settings and everything is fine. Guess I found the limits of the ender 3v2. Time for something bigger. Now the hard part - trying to justify it to my wife!!! Like my kids really need braces anyway.
Aussie Nuf Man
CC BY-SA 4.0
2024-12-12T09:37:19.463Z
Too bad 250mm/s is already too high. I highly recommend the Bambulab A1 mini as it can easily reach your desired speed and up to 500mm/s for a very low price.
Hacky
CC BY-SA 4.0
2024-12-05T13:45:15.463Z
2024-12-05T13:45:15.463Z
Hacky
<p>Recently I picked up some Creality Hyper Series filament. It says that it can run at 600mm/s. That 'feels' too quick. I have been running at 250mm/s and the quality is great.</p>
<p>BUT, when printing bit flat areas (with no retraction) I get Thermal Runaway problems. It is my guess that with the increase in feed rate, the hot end can't keep up with the heating requirements and slowly decreases in temperature.</p>
<p>I ran a 200x200x2mm square. The initial layer was fine. Thermal runaway would happen somewhere between the last 20% of layer 2 and the first 50% of layer 3. I've done other prints fine that have used more filament, but the print was more complex - ie more retraction and non-print travel times.</p>
<p>I'm running tests: Currently, I have dropped the fan speed to 75% and the filament speed to 200mm/s (I know - change one thing at a time, but I'm impatient)</p>

<creality-ender-3><thermal-runaway><part-testing>
Ender 3v2 thermal runaway after speed increase
Aussie Nuf Man
# Ender 3v2 thermal runaway after speed increase

(Asked by: username_0 on 2024-12-04)

Recently I picked up some Creality Hyper Series filament. It says that it can run at 600mm/s. That 'feels' too quick. I have been running at 250mm/s and the quality is great.

BUT, when printing bit flat areas (with no retraction) I get Thermal Runaway problems. It is my guess that with the increase in feed rate, the hot end can't keep up with the heating requirements and slowly decreases in temperature.

I ran a 200x200x2mm square. The initial layer was fine. Thermal runaway would happen somewhere between the last 20% of layer 2 and the first 50% of layer 3. I've done other prints fine that have used more filament, but the print was more complex - ie more retraction and non-print travel times.

I'm running tests: Currently, I have dropped the fan speed to 75% and the filament speed to 200mm/s (I know - change one thing at a time, but I'm impatient)

**Tags:** creality-ender-3, thermal-runaway, part-testing

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## 1 answers

### Answer by username_1 on 2024-12-05. Score: 2 | Accepted answer

Thermal runaway occurs when the hotend is on, but the temperature does not reach the desired temperature. This happens when printing faster than the hotend can heat the filament.
To be sure that this is really the case, keep an eye on the temperature during layer 2 and 3.
Lower the print speed to fix your issue. I am impressed that you achieve 600mm/s at all as it is well beyond the max speed of an Ender3 v2, so don't be surprised if you have to slow down though.

> **Comments:**
> **username_0**: 600mm is the filament max. I didn't go over 250. The build plate lost steps at that speed too. I just went back to the 50mm default settings and everything is fine. Guess I found the limits of the ender 3v2. Time for something bigger. Now the hard part - trying to justify it to my wife!!! Like my kids really need braces anyway.  
> **username_1**: Too bad 250mm/s is already too high. I highly recommend the Bambulab A1 mini as it can easily reach your desired speed and up to 500mm/s for a very low price.  

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