How to Split Objects Into Parts in Cura? Explained

While Cura doesn’t offer a lot in terms of manipulating an imported model, and rightly so, as it’s not a CAD software that requires to have such features, the need to split a model into multiple pieces comes up rather frequently when 3D printing, whether it’s due to the model being way too large, or to make it possible to print the part in a more reliable way.

In this guide, we will take you through the process of splitting objects into parts in Cura with two different methods; where one of the methods is suitable for splitting objects that are actually multiple objects bundled into one in a single STL file, and the other is a fairly limited workaround for splitting a standard singular object into multiple parts in a quick way.

As a bonus, we will also go through an alternative method of splitting a singular object into parts with another software called TinkerCAD, as it will allow you to conduct this process more reliably due to it being a CAD software explicitly designed to carry out such operations.

Splitting Objects Into Parts in Cura

While splitting objects into parts in Cura isn’t the most challenging process, the way of doing so is more of a workaround rather than a reliable method due to Cura not being an STL editor that supports such operations, meaning that it can fall short in many cases where you need better control over the way you’re splitting the object.

For this method, start by importing the object you would like to split into parts, which, for our example, will be a standard calibration cube.

cura calibration cube example


Next, navigate to the Move tab using the sidebar on the left, as this will allow you to move the 3D model you selected by entering positions for each of the axes.

cura move tab


Now, look at the bottom-left corner of the Cura window to find the Z-axis length of your imported model, divide that number by two, negate it, and put the value you have found in the Z-axis input box of the Move tab.

So, for instance, if the model you have imported has a Z-axis length of 20 mm, the value you would find by dividing by two and negating it would be -10, which is what you would enter into the Z-axis input box.

cura moving model on z axis


Once you do this, the model half of the model you have imported will be below the build plate, and your 3D printer will only print the top half that remains above, meaning that our next step is to get the 3D printer to print the other half that we have left out so far as well.

For this process, right-click the 3D model, choose the Multiply Selected option from the dropdown menu, and click OK, which will create a copy of the 3D model right next to the original.

cura multpliying selected model


Finally, choose one of the two 3D models you see on your screen, and rotate it 180 degrees on the Z-axis, which will effectively create a situation where the first model has one half, and the second model has the other half of the whole thing above the build plate, effectively splitting your 3D model into two pieces that you can print separately.

cura rotating model


From here, you can feel free to move the models on the X and Y axes the way you wish, use different print settings for each part, or even export each half as a separate Cura project file that you can load whenever necessary.

On the other hand, the downside of this method, as you may predict, is the fact that you won’t be able to rotate any of the parts to orient them in a particular way, which can be problematic in cases where the 3D model you’re splitting into two requires the rotation one of its parts to minimize overhangs and bridges.

Splitting Objects Into Parts (Submeshes) With the Cura Mesh Tools Plugin

If the object you want to split into individual parts is already designed to be in the form of multiple items (sub-meshes) that should technically be separate from each other but are bundled into one STL file, which causes Cura to recognize all of them as a single object, this method is for you.

stl file with multiple objects in it


Starting out, the first thing you will need to do is to click the Marketplace button on the top-right corner of the Cura window, which will bring up the Cura Plugin Manager window where you can find and add the plugin of your choice to your Cura installation.

cura marketplace


Next, type “mesh tools” into the search input, click the Install button next to the Mesh Tools entry, and follow the on-screen instructions to complete the installation of the plugin, which will end with restarting Cura for the plugin to load.

cura installing mesh tools


Finally, import the 3D model of your choice into Cura, right-click it, hover over the Mesh Tools entry, and choose the “Split model into parts” option from the dropdown menu.

cura split model into meshes with mesh tool plugin


Provided that the 3D model you have imported contains submeshes that it can be split into, you should now notice that you can select each of the two parts separately, meaning that you have successfully split the object into its parts with the Mesh Tools Plugin.

cura model split with mesh tools


On the other hand, if the 3D model you’re trying to split doesn’t contain submeshes, the Mesh Tools plugin will tell you that it couldn’t split the object into submeshes, which effectively means that you won’t be able to use this method for that particular 3D model.

cura mesh tools could not be split into submeshes


Splitting Objects Into Parts in TinkerCAD – Alternative Method

If you don’t mind using a different tool more suited for splitting objects into parts, we recommend TinkerCAD for the task, a free-of-charge, online 3D modeling program that will get the job done quickly and conveniently.

As each of the parts you split in TinkerCAD will become separate STL files, they won’t behave any differently than any standard 3D model you obtain from the internet, meaning that you will be able to rotate them the way you wish in Cura, unlike the first method where it’s not possible.

To start, click the Create button on the TinkerCAD dashboard (after registering & logging in), and choose the 3D Design option from the dropdown menu.

tinkercad creating 3d design


Next, click the Import button on the top-right corner, drag and drop the 3D model file you would like to split into parts and click the Import button to import the 3D model into TinkerCAD.

importing stl file in tinkercad


Now, make as many copies of the 3D model you’ve imported as you will be splitting it into parts by selecting it, clicking the Copy (CTRL+C) button on the top-left corner, and clicking the Paste (CTRL+V) button until you have the correct number of copies on the screen.

For this example, we will split the 3D model into two parts, so we will make only one copy to have two of the same 3D model on the screen.

copy pasting in tinkercad


With that done, click the cube shape on the top-right corner of the screen (select Basic Shapes from the dropdown menu above if you don’t see the cube), and click on an empty space on the Workplane, which will create a box on the screen.

adding box in tinkercad


Now, select the box you’ve created, and choose the Hole option on the menu that pops up in the top-right corner of the screen, right next to where you initially created the box.

changing the box type to hole in tinkercad


Next, drag the box over your 3D model and resize it to make it cover the entirety of the area that you will be splitting off.

Since we’re splitting the model into two halves in this example, we will make the box cover exactly one half by looking at the length (hover over the black square on the left or the right) of the 3D model first, dividing this value by two, and specifying it as the length of the box (click on the black square on the left or the right and type the value into the box at the bottom).

resizing box length in tinkercad


Once that’s done, select both the model you’ve imported and the box together, and click the group button on the top-right corner (CTRL+G key bind), which will remove the boxed-in portion of the 3D model, effectively giving us the first split-off piece.

split one half of the model off in tinkercad


Now, repeat this process for each of the copies you have made so far, and once you are through with all of them, you should have all of the individual pieces you have split the original 3D model into on your screen.

splitting model into two parts in tinkercad


With all the parts ready, it’s time to export them one by one into separate files by selecting one of the parts, clicking the Export button on the top-right corner, choosing the The selected shape option at the top of the pop-up, clicking the .STL button to export as an STL file and saving this file into a folder of your choice on your computer.

exporting as stl in tinkercad


Finally, by repeating the exporting process for all the parts to obtain different STL files for each, you will have access to all individual 3D model parts that you can import into Cura separately and print them in any way that works for you.

Conclusion

While it’s definitely possible to split objects into parts in Cura to an extent, the method to do so will only be handy in particular cases where you don’t need to change the orientation of the parts after splitting them, as the limited nature of this workaround won’t allow for such modifications.

On the other hand, as this is a fairly straightforward process in any CAD software, with TinkerCAD being the one we recommend due to it being free & easy to use and running directly in the web browser, our recommendation would be to do the necessary modifications outside of Cura and to import the modified file into Cura instead.