Cura

CURA is an open-sourced slicing software from Ultimaker compatible with most open-sourced 3D printing machines.

Downloading CURA

As of the writing of this article, Cura is in version 4.6. It works on all common OS platforms: Windows, Mac, and Linux. The minimum system requirements for Cura are:

   Windows Vista or newer
   Mac OSX 10.7 or newer
   Linux Ubuntu 15.04, Fedora 23, OpenSuse 13.2, ArchLinux or newer

You can download and run older versions if your computer does not fulfill the requirements for the newest version.

To install Cura, first, download it for your OS from this page. When the download is complete, run the installer and go through the usual steps.

Printer Selection

On first loading Cura, you’ll be asked to select a printer. If not, or if you want to set up a new printer, then select Settings > Printer.

You’ll now be confronted with a selection of many printers. If you downloaded through the link at the top, then the listed printers will all be Ultimaker. For all other printers click Other and if you’re lucky then your printer will be listed.

If not, head along to the manufacturer’s website and you may find that there’s a custom version of the Cura software (or a Cura profile) ready to download. If not, then select Custom and Add Printer.

You’ll now be shown the Add Printer screen and here you’ll need to know a bit about your printer. Again, details should be found on the manufacturer’s website. If you built the printer yourself, then you should know these details off by heart! Just enter the settings for your 3D printer in the Cura Machine settings window.

Adding a Model in .stl Format

Once you have set up Cura for your printer, it’s time to import a model into the Cura software.

To import a model, you can either click on the floating folder icon on the left or select File > Open File(s) from the top menu. Select an STL, OBJ, or 3MF file from your computer and Cura will import it. Wait a little bit and the model will appear on the Cura build area (the box in the center).

Preparing to Print

Adjust your model by scaling, rotating, duplicating, moving, etc. as necessary. If your model is ready to be printed, then it's time to adjust the settings panel on the right. You need to choose the correct settings in this panel in order to get your desired print quality.

Cura’s settings panel is divided into two sections. The topmost section is the Printer Settings and the next section is called Print Setup.

Print Settings

This section lets you select the right printer and material.

Printer: This is the printer that you selected in the first step. If you have more than one printer, then these can be set up, and then selected from this dropdown menu.

Material & Temperature: Quickly select the material and nozzle that your printer is using, and temperatures will be automatically adjusted. Print Setup

There are two options: Recommended and Custom

Recommended: The Recommended print options are calculated on the settings you input when initially configuring the Cura slicer for your printer. This option is a great choice when you’re just starting out or you just want to see how the software and printer communicate. Options are limited under the Recommended header, but you can quickly adjust quality, infill, plate adhesion, and basic support structures.

Custom: This is where the fun really starts and will enable you to adjust the print settings – from quality through to speed. We’ll look at this section and the options a little later.

The Recommended settings

Layer height As we have already discussed, 3D printers print an object by depositing layer after layer of material. The Layer Height slider in Cura controls the height of each individual layer. Here, the rule is: the lower the layer height, the better the print quality and vice versa. But note that setting a low value for Layer Height means that the print is going to take proportionally longer to complete. You need to make a trade-off between quality and print speed and pick your own sweet spot. 0.1 mm is a good starting point.

Infill in Cura The Infill slider controls the quality of the infill. Setting it to 0 % essentially means that you don’t want any infill and want your object to be hollow. Anything in the range of 10% – 40% is known as a light infill. The 50% – 90% range is called a medium infill. Setting the slider to 100% will produce the strongest model. Light is a good starting point.

When the Infill slider is set to above 0%, a checkbox titled Enable Gradual appears. Checking this box will make Cura gradually increase the amount of infill towards the top of the model. This lets you use a low value for Infill and still get decent top quality. It’s recommended that you check this box when using low values for Infill.

Helper parts in Cura These are your support and adhesion settings – controlled by two checkboxes titled Generate Support and Build Plate Adhesion. If this is your first print, then switch both on. As a rule, if your 3D model has plenty of contact with the print platform then switch off Build Plate Adhesion. If your model has no overhangs switch off Generate Support in Cura’s Helper Settings.

Slicing a Model

Generate a G-code file with Cura

The model is now print-ready and all you need to do is to export the file from Cura to either an SD card or send it directly to the printer. Cura will now handle everything converting the 3D STL or OBJ into the G-code file required by the printer.

   Save the 3D print file: Click either Save to file, Save to SD or Send to Printer button on the bottom right of the window.
   Estimate of time for 3D print: Cura will give you a rough estimate on the length of time it will take for your printer to print the piece.
   Start the 3D print: If tethered, sit back and wait for the printer to fire up and start printing. If you save to SD, then eject the SD card from your computer and transfer to your printer. Select print, select the file, and go.