# Cura is printing support on nothing?

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.

## 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.

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:

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.

• it might help to know other settings: Print speed, Printer (some have specific issues), nozzle diameter, temperature and material. – Trish Jan 12 at 22:15
• Please cut out the solution you posted in your question, this is in fact an answer, and paste it as an answer, you can even accept it after 24 hours! Please remember that multiple answers are allowed and voting/accepting is necessary for our community to grow. Thanks! – 0scar Jan 28 at 12:00

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.

Note on the updated printed part images, 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. 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.

• 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 Jan 8 at 11:11
• @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 Jan 8 at 11:15
• 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 Jan 8 at 11:17
• @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 Jan 8 at 11:19
• @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 Jan 9 at 11:07