Software modeling

Import STL into Blender

Overview

This section goes over how to load an .STL file into Blender, for viewing. There is also an edit mode to begin making changes.

Steps

• Launch blender on its own, without specifying any additional file name.
• Escape the splash logo
• Left-click on the default cube and press the Delete key to clear it
• Select the File menu, then Import
• Select Stl (.stl)
• Check the Bookmarks area and click on your folder shortcut (or add the Bookmark here)
• Click on a sample .stl file in your folder. You can use the sample hypocycloid.stl

View of a hypocycloid shape in 3D

Navigating

Navigating the model in Blender is straightforward. Hold the middle mouse button down and move the mouse to rotate the view.

Use the scroll wheel on the mouse to zoom in and out. Additionally some of the numeric keys (check the numlock) will change views. It is also helpful to check the full list of keyboard shortcuts for Blender.

Editing the model

(More advanced) At the top left, change from Object mode to Edit mode and you'll be able to select vertices, faces, and edges. You can also pivot around the viewpoint and select certain vertices and then use the selection Invert, to select the remaining ones.

• 

  Another STL model with selection inverted, showing front vertices selected

Other Programs and File Formats

Software programs

• Meshlab - view, repair, or adjust a mesh
• Freecad
• Fusion 360

File formats and alternatives

• STEP format for 2D and 3D (may require some repair)
• Use or create plugins with an API

Create your STL model programmatically (Python, C, etc)

STL is a 3D format which is essentially a set of triangles. If you are just working with a set of 2D points, you can use the STEP format to import/export between programs. Alternatively to STEP format you could still use STL, if working programmatically you could:

• Extend your (spline, etc) or set of 2D points with a Z offset and then stitch together a set of triangles.
• Use the .STL file format to describe your triangles
• Import into your software application (Blender, Fusion 360, Meshlab, Freecad, etc)
• Use the triangles as is, or just highlight the needed vertices in 2D and work with those.

Fusion 360 and mesh editing

• Use Insert mesh to import your .STL file
• Proceed to Mesh tab, Modify dropdown, and then Convert Mesh
• Be sure to select Parametric to keep the design transform in the design history.
• Also consider using the Reduce tool

Building on the example shown before, you could extrude faces, create holes and threads and any other modifications.

How to edit STL in Fusion 360

C example

// ===== Python example =====