<p>I see two problems with your printer: your filament seems to overheat in some areas, and you overextrude a little. My suspicion is, that your heating behavior is not well tuned and it overshoots the target temperature, leading to an overcooked filament, then the temperature drops below the temperature you need, leading to a wavy pattern and brown lines.</p>
<h2>fixing</h2>
<p>I suggest running a PID-tune cycle to get better heating behavior and then recalibrating the printer's extruder.</p>

CC BY-SA 4.0
2019-02-23T18:26:45.620Z
Does this happen with 195°C temperature too? I thought overcooking only happens on temperatures where PAL begins to boil which is beyond 210°
Also I have underextrusion too sometimes. You can see it on the top of the Y frame, there is a deeper notch. Supportmaterial also often gets underextruded at the beginning of a layer line (I have retraction off btw for that reason).
user6329530
CC BY-SA 4.0
2019-02-23T20:07:09.430Z
@user6329530 no, but your thermistor is probably inconsistent, resulting in the temperature swaying between above 210 °C and below 190 °C most likely.
Trish
CC BY-SA 4.0
2019-02-23T20:32:52.803Z
OK I will monitor the temperature on that thing maybe that pid tune works
user6329530
CC BY-SA 4.0
2019-02-25T15:50:00.230Z
Also make sure the hotend cooling fan is functioning properly.
Carl Witthoft
CC BY-SA 4.0
2019-02-23T17:32:54.247Z
2019-02-25T14:34:43.463Z
2020-06-18T08:29:41.667Z
Trish
<p>I noticed that thermistors provided with Chinese kits are not up to specs. Do yourself a favor and go to mouser or digikey and order a proper thermistor that is rated for the temperature range in question.</p>

CC BY-SA 4.0
2019-02-25T15:49:04.243Z
Hi, you make a good point, but we strongly urge answers to include a link to a part (or software, or whatever) which meets the requirements you propose.
Carl Witthoft
CC BY-SA 4.0
2019-02-24T19:47:02.597Z
2019-02-24T19:47:02.597Z
David Duley
<p>While you may very well be having temperature issues, I see two other issues:</p>

<p>First, I think the "notches" are z-wobble. Z-wobble is often caused by bent z-axis threaded rods.</p>

<p>I have a very similar Geeetech I3 printer. A lot of my z-wobble was cleaned up by removing the threaded rods and making them more straight. You can find videos to help you do that, just search for "threaded rod straightening".</p>

<p>The other thing I did was decouple the nut on the threaded rod from the x-carriage assembly, allowing it to float in the X-Y plane as it pushes the x-carriage up. The x-carriage ought to be guided up by the smooth rods/bearings. Unfortunately, if the nut is fixed to the x-carriage, the bent threaded rods are strong enough to over-power the smooth rods/bearings and make the whole assembly wobble.</p>

<p>The other problem I see is that your printer seems to be extruding too much filament. That is likely causing the little pyramid flair at the base of your print. If you tell the printer to extrude 100mm, it ought to extrude 100mm, not 110mm. Again, a search for "extruder calibration" will tell you how to do it. For me it involved extruding, measuring, a bit of math, adjusting some variables in Marlin, compiling and uploading the with Arduino IDE. Repeat until 100mm extrudes 100mm.</p>

CC BY-SA 4.0
2019-02-25T07:26:06.657Z
The resulting prints show more positional accuracy than Z-wobble, for Z-wobble it is too random and not in sync with pitch of the threads. But this can indeed cause a lot of problems for some 3D printers.
0scar
CC BY-SA 4.0
2019-03-07T00:57:45.103Z
@Oscar, I see what you're saying. It doesn't have the saw-tooth kind of thing, but there does appear to be a period of about 10 layers to the anomaly. If it does have anything to do with the threaded rods, it is easy to see by watching the rods while moving the z-axis 100mm.
Barry Grumbine
CC BY-SA 4.0
2019-02-25T05:43:31.837Z
2019-02-25T05:43:31.837Z
Barry Grumbine
<p>Here is an extreme example of notches caused by the printer. They go along all sides but are the strongest on the Y faces. They also happen quite randomly sometimes they are tiny sometimes they are strong. </p>

<p><a href="https://i.sstatic.net/VQ7Sr.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/VQ7Sr.jpg" alt="enter image description here"></a></p>

<p>I have tightened the belts already and while that reduced the ghosting on the X face a lot, it did nothing on the Y and actually never helped with the notches. This test cube has notches and ripples too but not that strong (the skirting on the bottom of that cube is my fault I set the bed level a little too low).</p>

<p><a href="https://i.sstatic.net/ZJDG4.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZJDG4.jpg" alt="enter image description here"></a></p>

<p><a href="https://i.sstatic.net/968jC.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/968jC.jpg" alt="enter image description here"></a></p>

<p>All models have been sliced with Ultimaker Cura and printed on an Anet A8. Flow = 110&nbsp;%, layer height of 0.1&nbsp;mm for the first example and 0.2&nbsp;mm for the cube, printing temperature = 195&nbsp;°C, no change on jerking and acceleration from default settings. Cube size = 20x20x20&nbsp;mm.</p>

<p>The printer has frame support <a href="https://www.thingiverse.com/thing:1672959" rel="nofollow noreferrer">https://www.thingiverse.com/thing:1672959</a> but no other upgrades yet.</p>

<print-quality><anet-a8>
Why does my printer create notches on the Y surface?
user6329530
# Why does my printer create notches on the Y surface?

(Asked by: username_0 on 2019-02-23)

Here is an extreme example of notches caused by the printer. They go along all sides but are the strongest on the Y faces. They also happen quite randomly sometimes they are tiny sometimes they are strong.

[![enter image description here](https://i.sstatic.net/VQ7Sr.jpg)](https://i.sstatic.net/VQ7Sr.jpg)

I have tightened the belts already and while that reduced the ghosting on the X face a lot, it did nothing on the Y and actually never helped with the notches. This test cube has notches and ripples too but not that strong (the skirting on the bottom of that cube is my fault I set the bed level a little too low).

[![enter image description here](https://i.sstatic.net/ZJDG4.jpg)](https://i.sstatic.net/ZJDG4.jpg)

[![enter image description here](https://i.sstatic.net/968jC.jpg)](https://i.sstatic.net/968jC.jpg)

All models have been sliced with Ultimaker Cura and printed on an Anet A8. Flow = 110 %, layer height of 0.1 mm for the first example and 0.2 mm for the cube, printing temperature = 195 °C, no change on jerking and acceleration from default settings. Cube size = 20x20x20 mm.

The printer has frame support <https://www.thingiverse.com/thing:1672959> but no other upgrades yet.

**Tags:** print-quality, anet-a8


---

## 3 answers

### Answer by username_1 on 2019-02-23. Score: 3 | Accepted answer

I see two problems with your printer: your filament seems to overheat in some areas, and you overextrude a little. My suspicion is, that your heating behavior is not well tuned and it overshoots the target temperature, leading to an overcooked filament, then the temperature drops below the temperature you need, leading to a wavy pattern and brown lines.

## fixing

I suggest running a PID-tune cycle to get better heating behavior and then recalibrating the printer's extruder.

> **Comments:**
> **username_0**: Does this happen with 195°C temperature too? I thought overcooking only happens on temperatures where PAL begins to boil which is beyond 210° Also I have underextrusion too sometimes. You can see it on the top of the Y frame, there is a deeper notch. Supportmaterial also often gets underextruded at the beginning of a layer line (I have retraction off btw for that reason).  
> **username_1**: @username_0 no, but your thermistor is probably inconsistent, resulting in the temperature swaying between above 210 °C and below 190 °C most likely.  
> **username_0**: OK I will monitor the temperature on that thing maybe that pid tune works  
> **username_2**: Also make sure the hotend cooling fan is functioning properly.  

---

### Answer by username_3 on 2019-02-24. Score: 0

I noticed that thermistors provided with Chinese kits are not up to specs. Do yourself a favor and go to mouser or digikey and order a proper thermistor that is rated for the temperature range in question.

> **Comments:**
> **username_2**: Hi, you make a good point, but we strongly urge answers to include a link to a part (or software, or whatever) which meets the requirements you propose.  

---

### Answer by username_4 on 2019-02-25. Score: 0

While you may very well be having temperature issues, I see two other issues:

First, I think the "notches" are z-wobble. Z-wobble is often caused by bent z-axis threaded rods.

I have a very similar Geeetech I3 printer. A lot of my z-wobble was cleaned up by removing the threaded rods and making them more straight. You can find videos to help you do that, just search for "threaded rod straightening".

The other thing I did was decouple the nut on the threaded rod from the x-carriage assembly, allowing it to float in the X-Y plane as it pushes the x-carriage up. The x-carriage ought to be guided up by the smooth rods/bearings. Unfortunately, if the nut is fixed to the x-carriage, the bent threaded rods are strong enough to over-power the smooth rods/bearings and make the whole assembly wobble.

The other problem I see is that your printer seems to be extruding too much filament. That is likely causing the little pyramid flair at the base of your print. If you tell the printer to extrude 100mm, it ought to extrude 100mm, not 110mm. Again, a search for "extruder calibration" will tell you how to do it. For me it involved extruding, measuring, a bit of math, adjusting some variables in Marlin, compiling and uploading the with Arduino IDE. Repeat until 100mm extrudes 100mm.

> **Comments:**
> **username_5**: The resulting prints show more positional accuracy than Z-wobble, for Z-wobble it is too random and not in sync with pitch of the threads. But this can indeed cause a lot of problems for some 3D printers.  
> **username_4**: @Oscar, I see what you're saying. It doesn't have the saw-tooth kind of thing, but there does appear to be a period of about 10 layers to the anomaly. If it does have anything to do with the threaded rods, it is easy to see by watching the rods while moving the z-axis 100mm.  

---

