[3D Software] How to Export STL/OBJ Files from Various 3D Software

【3D Software】How to export STL/OBJ files from various 3D software

If you want to turn your meticulously created 3D models from 3D software into physical objects, the most convenient way is to directly print them using a 3D printer. However, 3D printers only accept STL (Stereolithography) files,
a format specifically for 3D printing that converts the original curved or solid model into layered cross-sectional data. Most 3D software has the function to export to STL. How can you correctly export these
file formats to avoid printing issues?
In this article, we will compile the export methods for various common 3D software, allowing everyone to efficiently complete the preparatory work for 3D printing!
(PS. Some software only has the option to export OBJ files; you can save as OBJ first and then convert to STL.)
 
◎AutoCAD
◎3DS MAX
◎Solidworks 
◎Maya
◎Pro/ENGINEER
◎Rhino
◎SketchUP
◎Zbrush
◎Fusion 360

 
AutoCAD

Steps to export STL files

1. Click "Application" > "Export" > "Other Formats".
2. In the "Export Data" dialog box, enter the file name.
3. In "Files of type", select "Stereolithography (*.stl)". Click "Save".
4. Select one or more solid objects. All objects must be entirely within the positive XYZ octant of the World Coordinate System (WCS). That is, their X, Y, and Z coordinate values must be greater than zero.
5. The .stl file extension will be automatically appended to the file name.

※Additional notes
You export an AutoCAD 3D model as an .stl file for 3D printing, but the printed detail is not very good? As shown below:

In AutoCAD, you can adjust the precision of curved surfaces by changing the system variable "FACETRES".
A larger FACETRES value means more precise detail.
Since the default value of the AutoCAD system variable "FACETRES" is 0.5, many facets appear as shown in the image above.
You can increase the FACETRES value (e.g., 10), and the printed detail will improve significantly, as shown below:


3DS MAX

Notes for exporting STL files
1. Application Menu > Export > StereoLitho (*.STL)

2. Object Name: Enter the name for saving in STL format.
3. Binary/ASCII: Choose whether the STL output file is binary or ASCII (character) data.
ASCII STL files are much larger than binary STL files.
4. Select only the objects in the scene that you want to export.

Solidworks

Notes for exporting STL files
There is already a plugin that can directly export files to Cura! Please refer to this article for an introduction.
(You can install the plugin from within Cura.)

If you are using other slicing software, please continue reading for the conversion tutorial.

Steps to export an STL file:
1. Click File > Save As.
2. Select STL (*.stl) as the file type, then click Options.
3. Choose from the options described below, then click OK.
4. Click Save to export the file.
Output as
◎Choose Binary or ASCII as the file format. Binary files are smaller than ASCII files, but some other systems do not support Binary files. Choose the type supported by your target system.
◎Units. Select the unit of measurement.
◎Resolution. Controls the facet quality of non-planar surfaces exported in Stereolithography (STL) format. Lower deviation values produce STL files with higher overall part accuracy.
Files with higher accuracy (higher facet quality) are larger and can slow down model calculation.
Coarse or Fine. Default resolution.

Maya

Steps to export OBJ files

1. In the drop-down menu, select Window → Settings/Preferences → Plug-in Manager. A window will pop up.
2. In the C:/Program Files/Alias/Maya?.0/bin/plug-ins menu, find objExport.mll.
3. Check both the "loaded" and "auto load" options.
4. Then go to the drop-down menu and select File → Export All (export everything) or Export Selection (export selected parts).
5. Click the small square next to it → the Export All (Selection) Options window will pop up.
6. In General Options, select OBJexport from the File Type drop-down menu, then click Apply.
7. Enter the file name and select the save path.
 
Pro/ENGINEER

How to export STL files
 
1. Click "File" in the menu, select "Save a Copy", and the "Save a Copy" menu will pop up. Choose the folder to save the STL file, and select "STL" as the file type, then click the "OK" button.
2. Adjust the parameters of the STL file. In the "Export STL" dialog box that pops up, change the default value after "Chord Height" to "0", press the Enter key on the keyboard, and the software will automatically change the chord height to the minimum value. After clicking "OK", the STL file will be successfully saved.
 
※Notes on exporting files:
When saving in STL format in Pro/E, parameter adjustment is crucial. The more reasonable the parameter adjustment, the more accurate the saved file, and the better the effect when printed by a 3D printer.
An STL file should contain the coordinate values of the three vertices of each triangular facet and the normal vector of that facet. The normal vector is defined to have a magnitude of 1, pointing outwards from the solid, and the saving order of the three vertices should satisfy the right-hand rule. Therefore, the more facets a model has in STL format, the more precise the model.
However, more facets are not always better for 3D printing. So, when converting to STL in Pro/E, you can directly change the default value after "Chord Height" to "0" and press the Enter key on the keyboard. The software will automatically set the chord height to the minimum value. Other values can use the defaults.

Rhino

Steps to export STL files
1. From the File menu, select Export Selected Objects or Save As.
2. The File Type list in the dialog box that pops up will show the file types that can be exported.
3. In the File Type field, select STL.
4. In the File Name field, enter a name.
5. Set the save method.
◎Minimize Save
◎Save Geometry Only
6. If the exported file type has options, you can click the Options button to set them.
7. If the exported file type can only save mesh objects, a Mesh Conversion Settings dialog box will pop up for converting NURBS to meshes.

STL Export Options
File Type
1. Binary
2. ASCII
Export open objects
Adjust mesh
STL Export Warnings
A warning message will appear if the exported STL mesh is not closed.
Must Export
Saves open meshes.

STL Mesh Export Check
Some rapid prototyping machines can only read completely closed (watertight) STL mesh files.
Before exporting a model as an STL file for expensive rapid prototyping, it's best to ensure that the exported STL mesh meets the requirements of the rapid prototyping machine.

How to check if a mesh is watertight

1. Join mesh objects.
Join individual mesh objects into a polymesh.
2. Weld all vertices of the joined mesh object.
3. At the angle tolerance prompt, enter 180.
When the angle tolerance is set to 180 degrees, the Weld command welds all overlapping mesh vertices.
4. Execute the UnifyMeshNormals command.

Makes all mesh faces of the mesh object face the same direction (outward or inward).
Use the SelNakedMeshEdgePt command to check if the mesh still has holes.
If any mesh vertices are highlighted, it means the mesh has a hole there.

Avoid creating very large mesh files

◎You can use the Mesh command, which is the same as the render mesh conversion settings in the file properties. The difference is that the Mesh command creates an exportable mesh.
Exporting STL files from Rhino's surface objects also uses the same mesh conversion settings, but it is generally better practice to convert objects to mesh first, inspect them, and then export as STL files.

◎The best settings for converting different objects to mesh vary. To start, you can uncheck Max Angle and Max Aspect Ratio, and set Max Distance Edge to Surface (the maximum allowed distance between the midpoint of a mesh face edge and the surface) to the resolution of your rapid prototyping machine, which is approximately 0.005 inches (0.125 mm). After finding the best settings for your model and rapid prototyping machine, this process may become redundant as you may become accustomed to using validated settings to convert NURBS objects to mesh.

◎After creating the mesh, hide the NURBS object and use the FlatShade command to view the mesh that is not visually smoothed. If the mesh looks good, you can export it as an STL file. If the mesh quality is poor, you can delete it and create a new mesh with different settings.

◎When setting mesh conversion options, it is best to change only one setting at a time to compare the impact of that change. If most of the mesh looks good, but a small part doesn't, you can set the maximum aspect ratio to a value between 4 and 7. It is usually not worth setting the maximum distance from surface to edge to a value smaller than the rapid prototyping machine's resolution.

SketchUp



Export STL files using an extension
To draw 3D models in SketchUp and print them, you must install an extension to export STL files.
There are two ways to install extensions.
The first method is as follows:
1. Click on the "Extension Warehouse" in the toolbar.

2. The "Extension Warehouse" window appears. Click on the "SketchUP STL" item.

3. The "Install" window appears. Click "Install".


The second method is as follows:

1. First, download the extension. Download page: https://extensions.sketchup.com/en/content/sketchup-stl
The downloaded file will be sketchup-stl-2.1.4.rbz, where 2.1.4 may vary depending on the version.

2. Click the drop-down menu "Window" > "Preferences".

2. Click "Extensions" > "Install Extension", select the downloaded file sketchup-stl-2.1.4.rb, then click "Open".

3. When the following screen appears, click the "Yes" button.

4. When the following screen appears, click the "OK" button, then click the "OK" button again to close the "System Preferences" window.


5. Click the drop-down menu "File". If you see "Export STL...", it means the installation was successful.

 
Zbrush

Export as OBJ file
If the sculpted model is to be 3D printed, it must first be saved as an OBJ file and then saved as an STL file using other software.
First, click the "Tool" menu > "Export" button, then open the folder to save the file, name it, and click the Save button, as shown in the figure.

 
[Tip]: An OBJ file can only save one model, and only the subdivision level currently being edited. If there are multiple objects in the SubTool panel, they need to be saved separately, or select the desired model and click the Save button.

Fusion 360




2. Exporting a single component or body
Right-click on the component or body name, then select "Save as STL" from the drop-down menu. This will open the same panel as described above, but it allows direct export of a single component. Alternatively, use the "3D Print" function under the "Make" option in the top toolbar, and select the object you wish to export.

3. Exporting multiple bodies as individual STL files
This can be achieved by creating groups. First, select "New Group" under the "Create" tool in the toolbar. A small panel will appear. Then, select one or more bodies. Make sure to switch the option "From Bodies" and select only one body before clicking "Ok".After creating the group, it will be displayed at the bottom right. Then, add each additional body to this group. Finally, right-click on the group, select "Save as STL", and choose "One File" in the "Structure" panel.



Once you have the complete STL file, you can import it into slicing software for settings and then proceed with 3D printing! Want to use 3D printing but don't have a 3D printer? No problem, we also offer 3D printing services. Feel free to send us your files (remember to save them as STL files!) for our initial assessment!

References:
Autocad
Autocad

3DS MAX

Solidworks

Rhino

Sketchup

zbrush

Fusion 360