After you’ve downloaded and installed Blender, it’s time to enable the 3D printing toolbox add-on. This will give us everything we need to get a model ready for 3D printing success.

Most likely you’ll want to import an already-made 3D model into Blender to get it ready for printing. There are a number of great sites for Blender files, though not all of them are designed for 3D printing. If you want something that’s created to become a 3D print, we suggest you check out our list of the best sites to find STL files.

On the other hand, you might also want to design something yourself. If this is the case, there are a number of very helpful articles on how to use Blender.

Independently of which way you want to prepare the 3D model, here are some useful commands you might benefit from knowing about if you didn’t already:

• Tab: Enters edit mode
• G: Moves the model or vertices
• Shift + F: Fills a space between the selected vertices
• S or S + X, Y, or Z: Scales the object on a certain axis

There are two ways you can go about making a 3D model printable, and depending on the model, more or less work will be required. In particular, a model needs to be “manifold”. This means that it has to be one solid, filled object, with no holes or missing vertices.

Therefore, some models might need some fixing, but don’t worry! The process is very simple, and we’ll explain how to do so in the following sections.

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Non-Manifold Edges: Facts & Fixes

Very rarely will you be able to export a complex object while having it be perfectly manifold.

To check this, follow these steps:

1. Select the object you want to check.
2. Press N on your keyboard to make the toolbar appear, and then select the “3D printing toolbox” section.
3. Click on the button that says “Check All” (circled in red above).
4. Examine the result – it can have several values – focusing on “Non Manifold Edge”.

If it displays 0, your model is ready to be exported as a .stl file and imported in slicing software. If your model displays anything above 0, continue reading.

The simplest and easiest way to fix a non-manifold model inside Blender is to use its built-in cleanup tool. Next to the “Check All” button from before, there’s a “Clean up” section. Simply open it (making sure to have the model selected) and select “Make manifold”.

Note that this tool can also be found in older versions of Blender. The only drawback is that it can mess up your 3D model, so if this happens, read on to learn about a safer option.

This time, instead of using Blender, we’ll use an app called 3D Builder, which is available for Windows 8+ and 10.

1. Open up 3D Builder and import your model by clicking on “Open > Open object” and navigating to your 3D model’s file.
2. After opening, click on “Import model”.
3. The program should then notify you that there’s something wrong with the model and will tell you to click on the pop-up box to fix it.
4. Do so, and if everything went well, the model should now be manifold without changing much of its shape.

Finally, open the side menu in Blender and save the object as a .stl, ready to import into your slicing software.

Note that, when using 3D Builder, it’s still likely that some of the model’s shape will be changed in order to fill all holes and make the model manifold. However, from our experience, it’s much cleaner than Blender’s built-in clean-up function. How much it changes shape will depend on the model’s shape and how well it was made. Changes are completely normal and necessary in order for a model to be printable.

Once you have your model in a slicer, you can go ahead and 3D print it! Check out our filament guide or best print settings for suggestions.