Exporting a Part for 3D Printing
This document will describe the workflow necessary to export a 3D part in SolidWorks to a file that can then be imported to your 3D printing slicer program.
Two different options / workflows will be presented by examples, and the pros and cons of each will be discussed.
In addition, tips for dealing with a Part that contains multiple Bodies will be discussed.
In general, there are two approaches you can take:
- (Preferred) Export to a STEP file or
- Export to an STL file
Both workflow options will be described independently in sections below.
Prerequisites required:
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SolidWorks for Makers 2024
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Access to the Input-Inc. CAD repository (The February 2024 CAD Release will be referenced in the included examples)
Older versions of the Input Inc. CAD releases included a '3D Printable Parts' folder with pre-exported STL files. That folder has been deprecated, should NOT be used, and the STL files contained within are very likely out of date!
Do NOT use any pre-exported STL files. Always export the files (to either STEP or STL) yourself!
When exporting a SolidWorks 3D part (.SLDPRT) file for 3D printing, there are two popular files types: STEP (.step or .stp) and STL (.stl).
STEP files are preferred, and here's why:
- The file sizes are much smaller, and
- (most importantly) the original geometry is not modified
However, there is a downside to STEP files: Not all slicer programs currently support them.
So, the decision is clear: if your slicer program supports STEP files, use them!
STL files offer no advantage over STEP files, and actually have a severe disadvantage:
- The original part geometry is modified by tessellation during export!
Yes, you understood that correctly: STL files do not contain the original part geometry. They contain an approximation of the original geometry, and the accuracy of that approximation is only as good as settings you choose: poor approximation/small file size or better approximation/very large file sizes. If you have ever looked at a 3D printed part and wondered why it had facets instead of smooth curved surfaces, STL resolution settings are the culprit!
To illustrate this, here is a comparison of the [TUPR-B-COVR-01] Potentiometer Covering.SLDPRT file in Bambu Studio:
You can see that SolidWorks' default "fine" STL export setting results in an STL file that is very faceted (left) as a result of the tessellation that occurs during export. Custom STL export settings would need to be set in order to achieve a better result (middle) at the expense of file size. Compare that to the appearance of the exported STEP file (right): the file is only 6.4% the size and matches the original 3D part geometry!
Let's use a Part in the updated V2 Neck Drive Assembly as an example, so open the assembly [TUPR-C-V2] Neck Drive.SLDASM located in the \[04 TUPR] Upper Torso\[C] Neck Drive\[V2] Plate Interlock\ folder.
From this assembly, we will export [TUPR-C-V2-COMN-08] PCB Mount for 3D printing. The Part is highlighted in blue in the screenshot below:
Open this example Part by left-clicking it in the FeatureManager Design Tree and then clicking the Open Part icon as shown:
With the part to be exported now open, go to the File menu and select Export As... as shown in the image below:
In the Export dialog window that appears, select a folder to save the .STEP file to, and set the the file type to STEP AP214 as shown below. (The AP214 standard is overkill for this use, but we've seen no harm in using it and it appears to be compatible will all STEP-friendly slicers.)
Click the Export button and you are done. You can now import the .STEP file into your Slicer software and start printing.
We will use the same example Part that we used in Example 1 above, so refer to Example 1, Step 1: Opening the Part to be Exported if necessary to open the appropriate Part file.
With the part to be exported now open, go to the File menu and select Export As... as shown in the image below:
In the Export dialog window that appears,
- select a folder to save the .STL file to,
- set the the file type to STL, and then
- click the Options... button as indicated in the screenshot below
In the System Options - STL/3MF/AMF dialog that appears, set the Resolution to Custom, and the Deviation and Angle tolerance values to the recommended values shown below. NOTE: This will yield large file sizes but with geometry that most closely matches the original 3d part (as discussed in STEP vs STL above).
Click OK to close the System Options dialog, then click the Export button.
You will then be presented with the tessellated STL preview as shown below:
Click the Yes button to save the part. You can now import the .STL file into your Slicer software and start printing.
Let's now compare our Workflow 1 (.STEP) and Workflow 2 (.STL) parts.
We can see that the .STEP file is indeed a much smaller file than the .STL:
In Bambu Studio, the parts look indistinguishable, with no obvious faceting:
Sometimes, a Part file will contain multiple Bodies that are intended to be treated as separate objects... either for machining or 3D printing. One such example can be found in the [TUPR-A-COMN-08] Wire Tunnel part of the updated v2 [TUPR-A] Frame.SLDASM assembly, highlighted in blue in the screenshot below:
Open the [TUPR-A-COMN-08] Wire Tunnel part. This Part contains 2 Bodies that we will want to Export and print separately. If we select the Split operation in the FeatureManager Design Tree, we can see the "cut line" that splits this part into 2 separate Bodies:
Now, scroll up the FeatureManager Design Tree, and select / expand the Solid Bodies(2) entry as shown:
Select the Split1[1] body and it will highlight in blue on the Part as shown:
Now, go to the File menu and select Export As... as shown in the image below:
Follow whichever workflow you prefer (STEP or STL, referencing the examples above as necessary). Two additional steps are required, however:
- Append the file name to be something unique (such as adding "left" or "right" to the file name), as SolidWorks defaults to the name of the Part, not a unique name of the Body, and
- once you then click the Export button, you will be presented with an additional dialog window. Make sure to pick Selected bodies as shown below.
Once that Body is saved, select the other Split1[2] body in the FeatureManager Design Tree and Export it as well, again making sure to give the file a unique name.