<p>The image of the sliced print part is not very clear but printing support on air is a feature of Ultimaker Cura. This is done when support is laid on top of your print part if you enabled <code>Support Placement</code> to <code>Everywhere</code>, which you did. The default Cura setting for <code>Support Bottom Distance</code> (which is a sub-setting of <code>Support Z Distance</code>) is the layer thickness specified in <code>Layer Height</code>. If you have a layer height of 0.2&nbsp;mm, the <code>Support Bottom Distance</code> is also 0.2&nbsp;mm. For the top, option <code>Support Top Distance</code> this is two layer heights, so 0.4&nbsp;mm in this example. These options are visible in the expert mode, you can search for them in the search box, see image below.</p>

<p><strong>Why should you want air in between your part and the support?</strong></p>

<p>You'll soon find out when you want to <strong>remove supports</strong>, if no gap is used, the support will fuse to the print part. This is only interesting (no gap between print part and support structure) when you use a different filament for support like PVA or break-away filament; e.g. PVA dissolves in water.</p>

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

<hr>

<p>Note on the updated printed part images, you seem to have a <a href="https://3dprinting.stackexchange.com/search?q=stringing">stringing issue</a> that needs to be resolved first. Note that it tries to print support on top of inner side of the toroid. Maybe fusing the support will help you to slice better supports, or alternatively set option <code>Support Placement</code> to <code>Touching Buildplate</code> and use an experimental option called <code>Tree Support</code>. You can also try to change the print orientation by rotating the print. Last resort is to design the supports yourself in a 3D model software program.</p>

CC BY-SA 4.0
2020-01-08T11:11:08.767Z
Thanks, I will check the settings you mentioned in the evening and update here for community interest and to confirm the possible real problem on them.
fede72bari
CC BY-SA 4.0
2020-01-08T11:15:23.477Z
@fede72bari You do not need to update, this is not a forum (SE sites work differently, please take the [tour]), you ask a question and the community answers your question. You only update the question when the question is not clear and requires additional information. Beside an image of the sliced part which does not show the problem very good your question is fine, no need to update! If you want to answer yourself, just post your own answer, that is also allowed! And don't forget to accept an answer and vote when you have gained enough reputation. Welcome to 3DPrinting.SE!
0scar
CC BY-SA 4.0
2020-01-08T11:17:41.830Z
I will check thanks, but supports need to lay on something otherwise it will result in a wrong printing and missing part; I  am adding some images of the real printing in the original post. Clicking on the image to enlarge it the problem is clear, that is the best perspective I could get, it is a very small gap.
fede72bari
CC BY-SA 4.0
2020-01-08T11:19:58.487Z
@fede72bari Better images are very welcome! Also try to use a different color for support in the images. And yes, support cannot be printed in thin air, but also note that the slicer frequently doesn't correctly make an image of how it is printed, the visualization has its limits. Your support is printed onto the wheel like structure with a gap if I interpret the image correctly.
0scar
CC BY-SA 4.0
2020-01-08T11:37:34.197Z
yes, one support structure have a complete gap on the entire wheel structure where it should have been lean; on the other side Cura avoided the gap between the support an the wheel structure in the last 25%-30% of the bottom support surface and this saved the support itself.
fede72bari
CC BY-SA 4.0
2020-01-09T08:57:36.993Z
Mmmh there are many things unclear to me I try to summarize:
1. I cannot understand why the support cannot be "partially" fused on the bottom to a part of the model as it is usually on the top supporting the model itself. On the top is "weakly" fused so that is can be detached "easily", whycannot is on the bottom too?
2. not all the support laying on part of the model were wrong, some of them correctly hadn't that gap, I try to upload pictures of this too.
fede72bari
CC BY-SA 4.0
2020-01-09T09:03:45.550Z
3. `you seem to have a stringing issue that needs to be resolved first. Note that it tries to print support on top of inner side of the toroid.` if you refer to the "NOT PRINTED SUPPORT" in the picts, that is indeed the problem. Just because there are 0.4-0.5mm of GAP when the extruder tried to do it, it found nothing but air. But it was a problem of Cura, not of the machine. As shown in the very first slicer screenshot.
Thank you again for your support and patience. Hope it helps others too, I saw similar posts in Cura community.
fede72bari
CC BY-SA 4.0
2020-01-09T11:07:52.423Z
@fede72bari Try enabling "tree support" and "touching build plate" support type and reslice and see what happens. You are most welcome, but at SE sites you express gratitude by voting and accepting questions. Also note that comments are deleted after a while, especially when there are a lot and lengthy. In principle everything is already in the answer, comments shouldn't contain extra information. Hope to see you around!
0scar
CC BY-SA 4.0
2020-01-08T11:05:14.640Z
2020-01-08T12:37:42.603Z
2020-01-08T12:37:42.603Z
0scar
<p>I am new on 3D printing, but I cannot understand how support structures (in Ultimaker Cura 4.4.1) can stand if they do not lay on anything, but air. Throwing everything away after 9 hours of printing is not a good experience, did I do anything wrong? </p>

<p>In the attached screenshots images of the sliced model and Cura settings for support structures are shown. </p>

<p><a href="https://i.sstatic.net/g0IHj.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/g0IHj.png" alt="enter image description here"></a></p>

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

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

<h2>Demonstration of the issue</h2>

<p>Here some pics of the real printing results at 50&nbsp;%-60&nbsp;% of the work done. One of the two critical supports was barely done while other one, the same encircled in the slicer model, was not. I saved the printing attaching with some glue an "L" shaped piece of cardboard. </p>

<p><a href="https://i.sstatic.net/Z40SA.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Z40SA.jpg" alt="two critical support structures one barely done, the other one not"></a>
<a href="https://i.sstatic.net/PoLq2.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/PoLq2.jpg" alt="detail of the not done support structure"></a></p>

<p><strong>UPDATE 11/01/2020</strong></p>

<p>The tree support option greatly failed, but if anybody could suggest different settings I will be happy to try and report here an update. These are some screenshots:</p>

<p><a href="https://i.sstatic.net/4hPI3.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/4hPI3.png" alt="enter image description here"></a>
<a href="https://i.sstatic.net/Fsx6p.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Fsx6p.jpg" alt="enter image description here"></a>
<a href="https://i.sstatic.net/1KSW0.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/1KSW0.jpg" alt="enter image description here"></a></p>

<p>I've highlighted with red pencil the horizontal pieces of structure supported by nothing. I have to say anyway that the resulting model is worth to Moebius, could be an alien spaceship it-self!!! </p>

<p>I have partially fixed the problem setting the support horizontal expansion to 3 instead 0 mm as suggested by a more skilled friend. Anyway, this is clearly a workaround of an intrinsic bug that appears just with Anycubic printer setting and not with other printers configuration. The drawback of using 3mm instead 0mm is that the supports become too strong and some of them completely envelop model parts. </p>

<p><a href="https://i.sstatic.net/i7CJr.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/i7CJr.png" alt="enter image description here"></a></p>

CC BY-SA 4.0
2020-01-12T22:15:56.253Z
it might help to know other settings: Print speed, Printer (some have specific issues), nozzle diameter, temperature and material.
Trish
<ultimaker-cura><support-structures>
Cura is printing support on nothing?
fede72bari
# Cura is printing support on nothing?

(Asked by: username_0 on 2020-01-08)

I am new on 3D printing, but I cannot understand how support structures (in Ultimaker Cura 4.4.1) can stand if they do not lay on anything, but air. Throwing everything away after 9 hours of printing is not a good experience, did I do anything wrong?

In the attached screenshots images of the sliced model and Cura settings for support structures are shown.

[![enter image description here](https://i.sstatic.net/g0IHj.png)](https://i.sstatic.net/g0IHj.png)

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

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

## Demonstration of the issue

Here some pics of the real printing results at 50 %-60 % of the work done. One of the two critical supports was barely done while other one, the same encircled in the slicer model, was not. I saved the printing attaching with some glue an "L" shaped piece of cardboard.

[![two critical support structures one barely done, the other one not](https://i.sstatic.net/Z40SA.jpg)](https://i.sstatic.net/Z40SA.jpg)
[![detail of the not done support structure](https://i.sstatic.net/PoLq2.jpg)](https://i.sstatic.net/PoLq2.jpg)

**UPDATE 11/01/2020**

The tree support option greatly failed, but if anybody could suggest different settings I will be happy to try and report here an update. These are some screenshots:

[![enter image description here](https://i.sstatic.net/4hPI3.png)](https://i.sstatic.net/4hPI3.png)
[![enter image description here](https://i.sstatic.net/Fsx6p.jpg)](https://i.sstatic.net/Fsx6p.jpg)
[![enter image description here](https://i.sstatic.net/1KSW0.jpg)](https://i.sstatic.net/1KSW0.jpg)

I've highlighted with red pencil the horizontal pieces of structure supported by nothing. I have to say anyway that the resulting model is worth to Moebius, could be an alien spaceship it-self!!!

I have partially fixed the problem setting the support horizontal expansion to 3 instead 0 mm as suggested by a more skilled friend. Anyway, this is clearly a workaround of an intrinsic bug that appears just with Anycubic printer setting and not with other printers configuration. The drawback of using 3mm instead 0mm is that the supports become too strong and some of them completely envelop model parts.

[![enter image description here](https://i.sstatic.net/i7CJr.png)](https://i.sstatic.net/i7CJr.png)

**Tags:** ultimaker-cura, support-structures
> **Comments:**
> **username_1**: it might help to know other settings: Print speed, Printer (some have specific issues), nozzle diameter, temperature and material.  

---

## 1 answers

### Answer by username_2 on 2020-01-08. Score: 3

The image of the sliced print part is not very clear but printing support on air is a feature of Ultimaker Cura. This is done when support is laid on top of your print part if you enabled `Support Placement` to `Everywhere`, which you did. The default Cura setting for `Support Bottom Distance` (which is a sub-setting of `Support Z Distance`) is the layer thickness specified in `Layer Height`. If you have a layer height of 0.2 mm, the `Support Bottom Distance` is also 0.2 mm. For the top, option `Support Top Distance` this is two layer heights, so 0.4 mm in this example. These options are visible in the expert mode, you can search for them in the search box, see image below.

**Why should you want air in between your part and the support?**

You'll soon find out when you want to **remove supports**, if no gap is used, the support will fuse to the print part. This is only interesting (no gap between print part and support structure) when you use a different filament for support like PVA or break-away filament; e.g. PVA dissolves in water.

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

---

Note on the updated printed part images, you seem to have a [stringing issue](https://3dprinting.stackexchange.com/search?q=stringing) that needs to be resolved first. Note that it tries to print support on top of inner side of the toroid. Maybe fusing the support will help you to slice better supports, or alternatively set option `Support Placement` to `Touching Buildplate` and use an experimental option called `Tree Support`. You can also try to change the print orientation by rotating the print. Last resort is to design the supports yourself in a 3D model software program.

> **Comments:**
> **username_0**: Thanks, I will check the settings you mentioned in the evening and update here for community interest and to confirm the possible real problem on them.  
> **username_2**: @fede72bari You do not need to update, this is not a forum (SE sites work differently, please take the [tour]), you ask a question and the community answers your question. You only update the question when the question is not clear and requires additional information. Beside an image of the sliced part which does not show the problem very good your question is fine, no need to update! If you want to answer yourself, just post your own answer, that is also allowed! And don't forget to accept an answer and vote when you have gained enough reputation. Welcome to 3DPrinting.SE!  
> **username_0**: I will check thanks, but supports need to lay on something otherwise it will result in a wrong printing and missing part; I  am adding some images of the real printing in the original post. Clicking on the image to enlarge it the problem is clear, that is the best perspective I could get, it is a very small gap.  
> **username_2**: @fede72bari Better images are very welcome! Also try to use a different color for support in the images. And yes, support cannot be printed in thin air, but also note that the slicer frequently doesn't correctly make an image of how it is printed, the visualization has its limits. Your support is printed onto the wheel like structure with a gap if I interpret the image correctly.  
> **username_0**: yes, one support structure have a complete gap on the entire wheel structure where it should have been lean; on the other side Cura avoided the gap between the support an the wheel structure in the last 25%-30% of the bottom support surface and this saved the support itself.  
> **username_0**: Mmmh there are many things unclear to me I try to summarize: 1. I cannot understand why the support cannot be "partially" fused on the bottom to a part of the model as it is usually on the top supporting the model itself. On the top is "weakly" fused so that is can be detached "easily", whycannot is on the bottom too? 2. not all the support laying on part of the model were wrong, some of them correctly hadn't that gap, I try to upload pictures of this too.  
> **username_0**: 3. `you seem to have a stringing issue that needs to be resolved first. Note that it tries to print support on top of inner side of the toroid.` if you refer to the "NOT PRINTED SUPPORT" in the picts, that is indeed the problem. Just because there are 0.4-0.5mm of GAP when the extruder tried to do it, it found nothing but air. But it was a problem of Cura, not of the machine. As shown in the very first slicer screenshot. Thank you again for your support and patience. Hope it helps others too, I saw similar posts in Cura community.  
> **username_2**: @fede72bari Try enabling "tree support" and "touching build plate" support type and reslice and see what happens. You are most welcome, but at SE sites you express gratitude by voting and accepting questions. Also note that comments are deleted after a while, especially when there are a lot and lengthy. In principle everything is already in the answer, comments shouldn't contain extra information. Hope to see you around!  

---

