<p>After printing ~30 calibration test cubes I finally figured out the perfect settings. 
<li>
Apparently, the extrusion width in my slicer was set to a certain number, instead of 
percentage. I was printing at 0.45&nbsp;mm extrusion width, which was ~105&nbsp;% of the 0.4&nbsp;mm nozzle diameter, but less than 50&nbsp;% of the 0.8&nbsp;mm one. Changing the value to 130-140&nbsp;% 
solved the majority of my printing problems.
<li>
As I predicted, the 230-280&nbsp;℃ nozzle temp. was ridiculously high, even with the 
0.8&nbsp;mm nozzle.  I gradually lowered it to 210&nbsp;℃ (ironically, the value I chose at the very beginning). 
<li> There was some warping, so I cleaned the heatbed from the glue, put the glue again and decreased bed temp. to 50&nbsp;℃
<li> Finally, I decreased the flow from 1.3 to 1.05 and everything seems perfect now.</p>

CC BY-SA 4.0
2020-04-16T11:20:54.827Z
Nice that you shared your solution, this was hard to guess based on your question! This proves that stating all the print settings is a must for solving print problems. Your small extrusion width in combination with the large flow modifier mimics the wider extrusion width, but fails to do a proper job. +1 from me! *Note that I still find 100 mm/s to be fast for a 0.8 mm nozzle, but of it works, go for it!*
0scar
CC BY-SA 4.0
2020-04-16T13:05:44.540Z
@0scar Thank you! I found that larger prints required higher temperature/different settings, but luckily the most important part is done.
StLuke5
CC BY-SA 4.0
2020-04-16T10:12:15.650Z
2020-04-16T11:17:30.313Z
2020-04-16T11:17:30.313Z
StLuke5
<p>I am currently printing a simple cup out of PLA (I will later anneal it). My nozzle is 0.8&nbsp;mm and I'm using a 0.4&nbsp;mm layer height. Unfortunately, the layers keep separating. They don't detach completely, but there are 1 layer-tall, 3-7&nbsp;mm wide gaps. I increased the temperature, since my speed is 100&nbsp;mm/s. I also tried decreasing cooling and increasing the flow. This only helped a little bit. </p>

<p>Moreover, small increases in the temperature like 230/240&nbsp;&deg;C didn't work and now I have to use 270 and even 280&nbsp;&deg;C, which is crazy, considering my layer height is 0.4&nbsp;mm. Is there any easy solution that will increase the quality?</p>

<p>Settings:</p>

<ul>
<li>Material: PLA</li>
<li>Layer height: 0.4&nbsp;mm</li>
<li>Nozzle: 235&nbsp;&deg;C first layer, 270&nbsp;&deg;C for the rest.</li>
<li>Bed: 60&nbsp;&deg;C</li>
<li>Cooling: 62&nbsp;%</li>
<li>Speed: 100&nbsp;mm/s</li>
</ul>

<p>I have noticed that 280&nbsp;&deg;C is better for large prints (large area, not height) and small prints look better when I change the temperature to 240/250&nbsp;&deg;C.
This is how my prints look by now. The extrusion is very inconsistent, with overextrusion in the middle of the layers and gaps in the corners:</p>

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

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

<p>I suspect that the layer lines are not parallel to the heatbed and are over extruded, because of the high temp. I lowered it to 230&nbsp;&deg;C and there was no drooping/over extrusion, but there were more 'holes'.</p>

CC BY-SA 4.0
2020-04-14T19:21:24.400Z
Is it possible that your hotend cannot keep up with the flow? Hence the large temperature?
0scar
CC BY-SA 4.0
2020-04-14T19:31:05.680Z
The hotend is the default one that comes with Prusa MK3S. I don't know how powerful it is and I don't know how to check if that's the case. My flow is around 100 now.
StLuke5
CC BY-SA 4.0
2020-04-14T19:48:45.233Z
Just for troubleshooting, have you tried printing more slowly?
Aerik
CC BY-SA 4.0
2020-04-14T19:53:45.650Z
Wow, that is smoking hot for PLA ...
Pᴀᴜʟsᴛᴇʀ2
CC BY-SA 4.0
2020-04-14T21:49:48.613Z
@Aerik I have and it did help. I reduced the speed to 50mm/s and the result was better, but I still think it's too slow. I know someone who could do 100mm/s on the same printer, nozzle and layer height . I saw that a long time ago so I still have no idea how he pulled it off. Also, I changed the nozzle so as to print faster and it turns out that 0.4mm layer height at 50mm/s is far slower than for example 0.3mm at 150mm/s
StLuke5
CC BY-SA 4.0
2020-04-15T09:29:58.830Z
Large nozzles can make larger heights but need to be done slower unless you have a more powerful heater or longer meltzone.
Trish
CC BY-SA 4.0
2020-04-15T14:50:11.997Z
How about you swap in a 0.4 nozzle and see how well the print comes out -- and how long it takes.
Carl Witthoft
CC BY-SA 4.0
2020-04-15T18:01:30.710Z
@CarlWitthoft I've been using the 0.4mm nozzle for a long time now and the print quality is really nice (on the 0.4mm nozzle). I printed a different version of the current model on 0.3mm layer height and 150mm/s speed and it was really nice. I changed the nozzle for two reasons: faster printng and food safety (brass nozzles have lead, hardened steel ones don't) Unfortunately, I have just run into another problem. I'm getting the THERMAL RUNAWAY error, because my nozzle temp. drops from 280*C to 230*C. What's the cause of that?
StLuke5
CC BY-SA 4.0
2020-04-15T18:53:09.713Z
Edit: I fixed the THERMAL RUNAWAY error by placing a small E3D silicon part that protects my nozzle&hotend from excessive cooling caused by the part cooling fan.
StLuke5
<pla><3d-models><nozzle>
Prusa MK3S 0.8 mm nozzle layers separating
StLuke5
# Prusa MK3S 0.8 mm nozzle layers separating

(Asked by: username_0 on 2020-04-14)

I am currently printing a simple cup out of PLA (I will later anneal it). My nozzle is 0.8 mm and I'm using a 0.4 mm layer height. Unfortunately, the layers keep separating. They don't detach completely, but there are 1 layer-tall, 3-7 mm wide gaps. I increased the temperature, since my speed is 100 mm/s. I also tried decreasing cooling and increasing the flow. This only helped a little bit.

Moreover, small increases in the temperature like 230/240 °C didn't work and now I have to use 270 and even 280 °C, which is crazy, considering my layer height is 0.4 mm. Is there any easy solution that will increase the quality?

Settings:

* Material: PLA
* Layer height: 0.4 mm
* Nozzle: 235 °C first layer, 270 °C for the rest.
* Bed: 60 °C
* Cooling: 62 %
* Speed: 100 mm/s

I have noticed that 280 °C is better for large prints (large area, not height) and small prints look better when I change the temperature to 240/250 °C.
This is how my prints look by now. The extrusion is very inconsistent, with overextrusion in the middle of the layers and gaps in the corners:

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

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

I suspect that the layer lines are not parallel to the heatbed and are over extruded, because of the high temp. I lowered it to 230 °C and there was no drooping/over extrusion, but there were more 'holes'.

**Tags:** pla, 3d-models, nozzle

> **Comments:**
> **username_1**: Is it possible that your hotend cannot keep up with the flow? Hence the large temperature?  
> **username_0**: The hotend is the default one that comes with Prusa MK3S. I don't know how powerful it is and I don't know how to check if that's the case. My flow is around 100 now.  
> **username_2**: Just for troubleshooting, have you tried printing more slowly?  
> **username_3**: Wow, that is smoking hot for PLA ...  
> **username_0**: @username_2 I have and it did help. I reduced the speed to 50mm/s and the result was better, but I still think it's too slow. I know someone who could do 100mm/s on the same printer, nozzle and layer height . I saw that a long time ago so I still have no idea how he pulled it off. Also, I changed the nozzle so as to print faster and it turns out that 0.4mm layer height at 50mm/s is far slower than for example 0.3mm at 150mm/s  
> **username_4**: Large nozzles can make larger heights but need to be done slower unless you have a more powerful heater or longer meltzone.  
> **username_5**: How about you swap in a 0.4 nozzle and see how well the print comes out -- and how long it takes.  
> **username_0**: @username_5 I've been using the 0.4mm nozzle for a long time now and the print quality is really nice (on the 0.4mm nozzle). I printed a different version of the current model on 0.3mm layer height and 150mm/s speed and it was really nice. I changed the nozzle for two reasons: faster printng and food safety (brass nozzles have lead, hardened steel ones don't) Unfortunately, I have just run into another problem. I'm getting the THERMAL RUNAWAY error, because my nozzle temp. drops from 280*C to 230*C. What's the cause of that?  
> **username_0**: Edit: I fixed the THERMAL RUNAWAY error by placing a small E3D silicon part that protects my nozzle&hotend from excessive cooling caused by the part cooling fan.  

---

## 1 answers

### Answer by username_0 on 2020-04-16. Score: 1

After printing ~30 calibration test cubes I finally figured out the perfect settings.

- Apparently, the extrusion width in my slicer was set to a certain number, instead of
  percentage. I was printing at 0.45 mm extrusion width, which was ~105 % of the 0.4 mm nozzle diameter, but less than 50 % of the 0.8 mm one. Changing the value to 130-140 %
  solved the majority of my printing problems.
- As I predicted, the 230-280 ℃ nozzle temp. was ridiculously high, even with the
  0.8 mm nozzle. I gradually lowered it to 210 ℃ (ironically, the value I chose at the very beginning).
- There was some warping, so I cleaned the heatbed from the glue, put the glue again and decreased bed temp. to 50 ℃
- Finally, I decreased the flow from 1.3 to 1.05 and everything seems perfect now.

> **Comments:**
> **username_1**: Nice that you shared your solution, this was hard to guess based on your question! This proves that stating all the print settings is a must for solving print problems. Your small extrusion width in combination with the large flow modifier mimics the wider extrusion width, but fails to do a proper job. +1 from me! *Note that I still find 100 mm/s to be fast for a 0.8 mm nozzle, but of it works, go for it!*  
> **username_0**: @username_1 Thank you! I found that larger prints required higher temperature/different settings, but luckily the most important part is done.  

---

