<blockquote>
  <ol>
  <li>Should I replace the nozzle with this one so that I know what nozzle I've got and so I'm sure this isn't a problem?</li>
  </ol>
</blockquote>

<p>That is not really necessary. The exact nozzle size does not really matter.</p>

<blockquote>
  <p>Should I replace the filament with new 1.75 mm PLA? If so, why?</p>
</blockquote>

<p>No, there's no reason to do that. Going from 3&nbsp;mm to 1.75&nbsp;mm filament usually requires replacing the entire extruder.</p>

<blockquote>
  <p>How do I fix the extruder?</p>
</blockquote>

<p>Tighten the grub screw (the "black hole") with a hex key.</p>

<blockquote>
  <p>Is the unconnected fan important and if so: what do I do with it? There's no remaining wire to connect it to.</p>
</blockquote>

<p>The fan appears to be cooling the stepper motor. This shouldn't really be necessary, the stepper should be fine without any additional cooling. People tend to "upgrade" their printers by adding unnecessary bells and whistles so it is possible the original owner added this fan just because they wanted to, and not because it is necessary.</p>

<blockquote>
  <p>How tight should the 4 screws that hold the filament between the extruder and the rolling disk be?</p>
</blockquote>

<p>Tight enough that the extruder grips the filament and is able to extrude it consistently. If it is too tight it might deform the filament too much which could cause printing problems but it should be obvious if this is the case. There is a wide margin here so don't worry about this too much.</p>

CC BY-SA 4.0
2020-04-24T09:10:24.217Z
If the stepper fan is not used, the fan should be better removed to improve cooling
FarO
CC BY-SA 4.0
2020-04-24T07:45:25.960Z
2020-04-24T07:54:52.743Z
2020-04-24T07:54:52.743Z
Tom van der Zanden
<blockquote>
  <p>Should I replace the nozzle with this one so that I know what nozzle I've got and so I'm sure this isn't a problem?</p>
</blockquote>

<p>It appears the default nozzle size is 0.3&nbsp;mm. The linked nozzle is a direct replacement.</p>

<blockquote>
  <p>How do I fix the extruder?</p>
</blockquote>

<p>The "feed knurl", usually called the extruder gear is attached to the stepper shaft using a fine grub screw ("threaded pin" is a bad choice of words...). The black hole you mention is the hole of the screw (it should be in there, usually an allen key or flat screwdriver should be used). Position it so that the screw is tightened against the flat spot on the stepper shaft.</p>

<blockquote>
  <p>Should I replace the filament with new 1.75 mm PLA? If so, why?</p>
</blockquote>

<p>If the PLA has been open for a year and not stored properly it could have taken up moisture, I would buy a new spool (3.0&nbsp;mm) of filament, not 1.75&nbsp;mm.</p>

<blockquote>
  <p>Is the unconnected fan important and if so: what do I do with it? There's no remaining wire to connect it to.</p>
</blockquote>

<p>The fan doesn't look as if this is a default fan, this fan is mounted onto cooling fins probably put there by the previous owner to cool the extruder stepper. Maybe the printer has been enclosed and used to print ABS at elevated temperatures. For Printing PLA cooling the extruder stepper would not be necessary as it doesn't require an elevated print temperature.</p>

<blockquote>
  <p>How tight should the 4 screws that hold the filament between the extruder and the rolling disk be?</p>
</blockquote>

<p>The 4 screws need to be tight enough for the extruder gear to leave indentations on the filament, but not too deep.</p>

CC BY-SA 4.0
2020-04-24T08:49:59.527Z
Thank you! Where'd you find the default nozzle size? The manual on the SD card says the nozzle diameter is 0.5 mm. Would the wrong nozzle size in the slicer show significant differences in the results?
Stefan
CC BY-SA 4.0
2020-04-24T10:22:23.410Z
@Stefan yes - the nozzle dameter dictates directly how the print is configured. 0.5 mm in the setting with a 0.3 mm nozzle gets you a different print than having the same settings, your prints should be lacking stability.
Trish
CC BY-SA 4.0
2020-04-24T10:28:19.163Z
You'll see the difference when printing. Make that a new question then. :-)
0scar
CC BY-SA 4.0
2020-04-24T07:50:12.887Z
2020-04-24T10:26:48.843Z
2020-04-24T10:26:48.843Z
0scar
<p>I've got a Renkforce RF1000 which should be a good 3D printer. I got it second-hand for my birthday one year ago. I've got no way of contacting the old owner.</p>
<p>I spend a good amount of hours fine-tuning the slicer settings last year but at best got mediocre prints. Between September and a week ago I lived somewhere else and didn't touch my printer.</p>
<p>Now here's what I don't know:</p>
<ul>
<li>I don't know what parts are replaced</li>
<li>I don't know what my nozzle size is</li>
<li>I don't know if the limit switches are calibrated correctly
<ul>
<li>Though I think they are. This doesn't seem to be a problem. I did re-calibrate the Z-axis</li>
</ul>
</li>
</ul>
<p>Here are some important details:</p>
<ul>
<li>I use 3 mm Renkforce PLA filament which I print at 190 °C on a bed heated at 60 °C. The PLA is over one year old now.</li>
<li>There's a fan on the motor on top that isn't connected to anything.</li>
</ul>
<p>Here are some of the problems I've got:</p>
<ul>
<li>I've had multiple prints failing due to the extruder not working properly. The motor keeps on spinning but the &quot;feed knurl&quot; remains stationary</li>
<li>I can't seem to get the right extraction settings</li>
<li>I can't seem to get my prints to consistently stick. It tends to work when I heat the bed to 60 °C and use glue and get lucky.</li>
</ul>
<p>Feel free to give any thoughts you've got. These are the most important questions I've got:</p>
<ol>
<li>Should I replace the nozzle with <a href="https://www.conrad.com/p/renkforce-nozzle-v2-03-mm-suitable-for-3d-printer-renkforce-rf1000-renkforce-rf2000-1296238?searchTerm=renkforce%20nozzle&amp;searchType=suggest&amp;searchSuggest=product" rel="nofollow noreferrer">this one</a> so that I know what nozzle I've got and so I'm sure this isn't a problem?</li>
<li>Should I replace the filament with new 1.75 mm PLA? If so, why?</li>
<li>How do I fix the extruder?</li>
</ol>
<ul>
<li>I tried getting the &quot;feed knurl&quot; off but can't seem to do this easily. I've got some super glue I could try to put in there but something's telling me this might be a very bad idea...</li>
</ul>
<ol start="4">
<li>Is the unconnected fan important and if so: what do I do with it? There's no remaining wire to connect it to.</li>
<li>How tight should the 4 screws that hold the filament between the extruder and the rolling disk be?</li>
</ol>
<p>For now, these are all hardware problems. I can post my Slic3r settings too but I believe the hardware should be fixed before going into slicer settings.</p>
<p>Here are some pictures showing the problems:</p>
<p><a href="https://i.sstatic.net/ynZ9v.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ynZ9v.jpg" alt="Top image one" /></a></p>
<p>This is the extruder. The feeding mechanism can be seen in front. It shows the &quot;feed knurl&quot; of which the inside spins while the outside remains stationary (question 3). Next to it are 4 screws which determine how tight the filament is held against the extruder (question 5). On the back it shows a black fan, this got placed by the previous owner but isn't connected (question 4).</p>
<p><a href="https://i.sstatic.net/Cu0UM.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Cu0UM.jpg" alt="Image unconnected fan with unscrewed extruder" /></a></p>
<p>This image shows the unconnected fan (question 4) to the right. Behind it is the motor that's connected to the extruder. The motor works but the extruder doesn't spin with it. The extruder has a little black hole on top.</p>
<p><a href="https://i.sstatic.net/WyWj2.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/WyWj2.jpg" alt="Front view extruder" /></a></p>
<p>This shows the extruder from the front. The inner layer spins, the outer layer doesn't (question 3)</p>
<p><a href="https://i.sstatic.net/yZd1o.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/yZd1o.jpg" alt="Failed print example" /></a></p>
<p>These are some of the prints when the extruder was still working.</p>
<p><a href="https://i.sstatic.net/zdToY.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zdToY.jpg" alt="Nozzle and print bed" /></a></p>
<p>Nozzle and print bed (question 1)</p>

CC BY-SA 4.0
2020-04-23T22:24:44.603Z
If the stepper spins, but not the extruder gear ("feed knurl"), you need to tighten the grub screw.
0scar
CC BY-SA 4.0
2020-04-24T07:33:38.627Z
How would I do this? The gear has a small black hole on top but I can't find it's use. The manual only says this about it:
"Push the feed knurl onto the axis of the actuator and attach
it with the threaded pin. Apply threaded pin with threadlocker
varnish. The motor axis must end flush with the upper edge of the feed
knurl."
Stefan
CC BY-SA 4.0
2020-04-24T07:36:31.423Z
That "black hole" on top is the grub screw ("threaded pin" in the Chinglish instructions). It can be tightened with a hex key to lock the drive gear to the motor's shaft.
Tom van der Zanden
CC BY-SA 4.0
2020-04-24T09:08:44.217Z
Be careful with Z calibration: just like the other ones, it's better if you just calculate the theoretical value and stick to it. Also, I use 5 years old 3 mm PLA (after drying it in a silica filled box) with no problems, it only tends to snap if left stretched for a while, so I remove it from the extruder when not in use
FarO
CC BY-SA 4.0
2020-04-24T09:10:57.283Z
Nozzles are consumables. If you don't know the age (in "spools") of the old one, don't even ask and replace it.
FarO
CC BY-SA 4.0
2020-04-24T09:24:21.373Z
Would PLA snapping when left in overnight be a sign of bad or expired filament? It's connected like [this](https://preview.redd.it/ym0lilmphku41.jpg?width=1824&format=pjpg&auto=webp&s=523ef73bbee9dfd2747ebd02fd838a630d984c0e) (forgot to add this detail earlier)
Stefan
CC BY-SA 4.0
2020-04-24T10:18:55.840Z
it can, but it also can be a bad filament path with a sharp bend.
Trish
CC BY-SA 4.0
2020-04-24T13:39:31.677Z
@Stefan it's filament from over 4 years ago... and once dried at too high temperature. It prints fine, but there are likely microcracks which make the filament snap when stretched.
FarO
<extruder><troubleshooting><renkforce-rf1000>
Can you help me improve my Renkforce RF1000 print quality?
Stefan
# Can you help me improve my Renkforce RF1000 print quality?

(Asked by: username_0 on 2020-04-23)

I've got a Renkforce RF1000 which should be a good 3D printer. I got it second-hand for my birthday one year ago. I've got no way of contacting the old owner.

I spend a good amount of hours fine-tuning the slicer settings last year but at best got mediocre prints. Between September and a week ago I lived somewhere else and didn't touch my printer.

Now here's what I don't know:

* I don't know what parts are replaced
* I don't know what my nozzle size is
* I don't know if the limit switches are calibrated correctly
  + Though I think they are. This doesn't seem to be a problem. I did re-calibrate the Z-axis

Here are some important details:

* I use 3 mm Renkforce PLA filament which I print at 190 °C on a bed heated at 60 °C. The PLA is over one year old now.
* There's a fan on the motor on top that isn't connected to anything.

Here are some of the problems I've got:

* I've had multiple prints failing due to the extruder not working properly. The motor keeps on spinning but the "feed knurl" remains stationary
* I can't seem to get the right extraction settings
* I can't seem to get my prints to consistently stick. It tends to work when I heat the bed to 60 °C and use glue and get lucky.

Feel free to give any thoughts you've got. These are the most important questions I've got:

1. Should I replace the nozzle with [this one](https://www.conrad.com/p/renkforce-nozzle-v2-03-mm-suitable-for-3d-printer-renkforce-rf1000-renkforce-rf2000-1296238?searchTerm=renkforce%20nozzle&searchType=suggest&searchSuggest=product) so that I know what nozzle I've got and so I'm sure this isn't a problem?
2. Should I replace the filament with new 1.75 mm PLA? If so, why?
3. How do I fix the extruder?

* I tried getting the "feed knurl" off but can't seem to do this easily. I've got some super glue I could try to put in there but something's telling me this might be a very bad idea...

4. Is the unconnected fan important and if so: what do I do with it? There's no remaining wire to connect it to.
5. How tight should the 4 screws that hold the filament between the extruder and the rolling disk be?

For now, these are all hardware problems. I can post my Slic3r settings too but I believe the hardware should be fixed before going into slicer settings.

Here are some pictures showing the problems:

[![Top image one](https://i.sstatic.net/ynZ9v.jpg)](https://i.sstatic.net/ynZ9v.jpg)

This is the extruder. The feeding mechanism can be seen in front. It shows the "feed knurl" of which the inside spins while the outside remains stationary (question 3). Next to it are 4 screws which determine how tight the filament is held against the extruder (question 5). On the back it shows a black fan, this got placed by the previous owner but isn't connected (question 4).

[![Image unconnected fan with unscrewed extruder](https://i.sstatic.net/Cu0UM.jpg)](https://i.sstatic.net/Cu0UM.jpg)

This image shows the unconnected fan (question 4) to the right. Behind it is the motor that's connected to the extruder. The motor works but the extruder doesn't spin with it. The extruder has a little black hole on top.

[![Front view extruder](https://i.sstatic.net/WyWj2.jpg)](https://i.sstatic.net/WyWj2.jpg)

This shows the extruder from the front. The inner layer spins, the outer layer doesn't (question 3)

[![Failed print example](https://i.sstatic.net/yZd1o.jpg)](https://i.sstatic.net/yZd1o.jpg)

These are some of the prints when the extruder was still working.

[![Nozzle and print bed](https://i.sstatic.net/zdToY.jpg)](https://i.sstatic.net/zdToY.jpg)

Nozzle and print bed (question 1)

**Tags:** extruder, troubleshooting, renkforce-rf1000
> **Comments:**
> **username_1**: If the stepper spins, but not the extruder gear ("feed knurl"), you need to tighten the grub screw.  
> **username_0**: How would I do this? The gear has a small black hole on top but I can't find it's use. The manual only says this about it: "Push the feed knurl onto the axis of the actuator and attach it with the threaded pin. Apply threaded pin with threadlocker varnish. The motor axis must end flush with the upper edge of the feed knurl."  
> **username_2**: That "black hole" on top is the grub screw ("threaded pin" in the Chinglish instructions). It can be tightened with a hex key to lock the drive gear to the motor's shaft.  
> **username_3**: Be careful with Z calibration: just like the other ones, it's better if you just calculate the theoretical value and stick to it. Also, I use 5 years old 3 mm PLA (after drying it in a silica filled box) with no problems, it only tends to snap if left stretched for a while, so I remove it from the extruder when not in use  
> **username_3**: Nozzles are consumables. If you don't know the age (in "spools") of the old one, don't even ask and replace it.  
> **username_0**: Would PLA snapping when left in overnight be a sign of bad or expired filament? It's connected like [this](https://preview.redd.it/ym0lilmphku41.jpg?width=1824&format=pjpg&auto=webp&s=523ef73bbee9dfd2747ebd02fd838a630d984c0e) (forgot to add this detail earlier)  
> **username_4**: it can, but it also can be a bad filament path with a sharp bend.  
> **username_3**: @Stefan it's filament from over 4 years ago... and once dried at too high temperature. It prints fine, but there are likely microcracks which make the filament snap when stretched.  

---

## 2 answers

### Answer by username_1 on 2020-04-24. Score: 2 | Accepted answer

> Should I replace the nozzle with this one so that I know what nozzle I've got and so I'm sure this isn't a problem?

It appears the default nozzle size is 0.3 mm. The linked nozzle is a direct replacement.

> How do I fix the extruder?

The "feed knurl", usually called the extruder gear is attached to the stepper shaft using a fine grub screw ("threaded pin" is a bad choice of words...). The black hole you mention is the hole of the screw (it should be in there, usually an allen key or flat screwdriver should be used). Position it so that the screw is tightened against the flat spot on the stepper shaft.

> Should I replace the filament with new 1.75 mm PLA? If so, why?

If the PLA has been open for a year and not stored properly it could have taken up moisture, I would buy a new spool (3.0 mm) of filament, not 1.75 mm.

> Is the unconnected fan important and if so: what do I do with it? There's no remaining wire to connect it to.

The fan doesn't look as if this is a default fan, this fan is mounted onto cooling fins probably put there by the previous owner to cool the extruder stepper. Maybe the printer has been enclosed and used to print ABS at elevated temperatures. For Printing PLA cooling the extruder stepper would not be necessary as it doesn't require an elevated print temperature.

> How tight should the 4 screws that hold the filament between the extruder and the rolling disk be?

The 4 screws need to be tight enough for the extruder gear to leave indentations on the filament, but not too deep.

> **Comments:**
> **username_0**: Thank you! Where'd you find the default nozzle size? The manual on the SD card says the nozzle diameter is 0.5 mm. Would the wrong nozzle size in the slicer show significant differences in the results?  
> **username_4**: @Stefan yes - the nozzle dameter dictates directly how the print is configured. 0.5 mm in the setting with a 0.3 mm nozzle gets you a different print than having the same settings, your prints should be lacking stability.  
> **username_1**: You'll see the difference when printing. Make that a new question then. :-)  

---

### Answer by username_2 on 2020-04-24. Score: 2

> 1. Should I replace the nozzle with this one so that I know what nozzle I've got and so I'm sure this isn't a problem?

That is not really necessary. The exact nozzle size does not really matter.

> Should I replace the filament with new 1.75 mm PLA? If so, why?

No, there's no reason to do that. Going from 3 mm to 1.75 mm filament usually requires replacing the entire extruder.

> How do I fix the extruder?

Tighten the grub screw (the "black hole") with a hex key.

> Is the unconnected fan important and if so: what do I do with it? There's no remaining wire to connect it to.

The fan appears to be cooling the stepper motor. This shouldn't really be necessary, the stepper should be fine without any additional cooling. People tend to "upgrade" their printers by adding unnecessary bells and whistles so it is possible the original owner added this fan just because they wanted to, and not because it is necessary.

> How tight should the 4 screws that hold the filament between the extruder and the rolling disk be?

Tight enough that the extruder grips the filament and is able to extrude it consistently. If it is too tight it might deform the filament too much which could cause printing problems but it should be obvious if this is the case. There is a wide margin here so don't worry about this too much.

> **Comments:**
> **username_3**: If the stepper fan is not used, the fan should be better removed to improve cooling  

---

