Import
Bring in a STEP, STL, OBJ, 3MF or SOLIDWORKS file as parts, and how to turn a Fusion or Inventor file into STEP.
- Import AdvancedPart workspace toolbar
| SchoolCAD | Onshape | Fusion | SOLIDWORKS |
|---|---|---|---|
| Import | Import | Upload / Insert | Open / Insert Part |
Import brings a 3D model into your design. Many suppliers let you download a STEP file of what they sell, such as a hinge, a battery holder or a motor: import it, then design around the real part (put the screw holes in the right place, and leave room for the motor). You can also bring in a model from Onshape, Fusion or SOLIDWORKS, or a 3D print file from Thingiverse, Printables or a slicer.
| File | What comes in |
|---|---|
| STEP (.step, .stp) | Exact solids, with their names and colours from the file (every part of an assembly). You can fillet, drill, cut, mate and draw them like your own parts. |
| SOLIDWORKS (.sldprt, .sldasm) | A part as an exact solid with its colour (a mesh first, for a few seconds); an assembly (with its part files) with every part in place. See Open SOLIDWORKS files. |
| STL, OBJ, 3MF (.stl, .obj, .3mf) | A mesh: the shape made of triangles. Its flat faces are faces you can sketch on, measure and mate to; it can be cut, exported and 3D printed. A 3MF file from Bambu Studio or PrusaSlicer brings each object with its name and colour. For fillets and holes that follow its shape, turn it into an exact solid with Mesh to solid. |
Three ways in#
- Drag the file onto SchoolCAD: it is imported into the design that is open. Several files at once work too.
- Open file (the folder button, or Documents → Open file) with a STEP, STL, OBJ, 3MF or SOLIDWORKS file: a new design named after the file, with the file imported (as Fusion and SOLIDWORKS open one).
- Import on the toolbar (in Advanced, with Library ▾ in a narrow window), or press ` and type import.
Then put the parts in place with Mate or Transform, or with Move by (below).
Sub-assemblies#
A STEP file of an assembly keeps its sub-assemblies: the parts come in inside folders named after them, as they were in Fusion, SOLIDWORKS, Inventor or Onshape (a drawer, a cabinet, a slide). In Parts, and in the Assembly's instance list:
- Click the arrow to open or close a sub-assembly, and its name to select every part in it. Hold the pointer over it to see its overall size, such as whether a cabinet will fit through a door.
- The eye hides or shows all of it. Right-click it to Rename, Isolate, Zoom to it, Export it, make a new sub-assembly inside it, or Ungroup it (its parts move up a level).
- Your own parts can go in sub-assemblies too: select them, right-click and choose Make a sub-assembly.
- The bill of materials and its CSV list each part's sub-assembly.
A design with more than 40 parts starts with its sub-assemblies closed, so the list stays short.
Fusion, Inventor and other CAD files#
SchoolCAD opens SOLIDWORKS parts and assemblies itself: see Open SOLIDWORKS files.
A .f3d (Fusion), .ipt or .iam (Inventor), .x_t (Parasolid) or .catpart (CATIA) file is that program's own format, which only it can open. So SchoolCAD opens the standard file every CAD program saves: STEP. Give it one of those files and SchoolCAD shows how to save it as STEP in that program:
- Fusion: File → Export → STEP.
- Inventor: File → Export → CAD Format → STEP.
- SOLIDWORKS, for exact solids: File → Save As → **STEP AP214 (*.step)**.
- No copy of the program? Onshape (free for education) can import the file and export STEP.
Options#
To move the parts or change the file, double-click the Import feature in the feature tree. Its name starts with Import.
| Option | What it does |
|---|---|
| Move by | Moves the imported parts along X, Y and Z, in mm. |
| Replace file… | Swaps in another file, such as a newer version of the part. |
The top of the dialog shows the file's name, how many solids it holds, its size, and mesh for a mesh.
Tips#
- The file is kept with your design, compressed to about a fifth of its size, so it goes with Save file, a shared link and Hand in. A big one (over about 7 MB) is kept in the browser's own file store, which has much more room, and Save file puts it back inside the saved design.
- STL, OBJ and 3MF files can be up to 120 MB. A STEP file over 30 MB, such as a whole robot, opens in the Large assembly view, where you can look around it and open any part from it as an exact solid. A mesh with more than 200,000 triangles is simplified so the browser can work with it; download just the part you need, not a whole machine.
- To change the shape of an imported part, change it in the program it came from, export it again, then use Replace file….
- Imported parts have no material yet. Right-click a part in the parts list to choose one, so its mass and cost are right.
- Importing a STEP file needs SchoolCAD's exact 3D engine. The first time, it takes a few seconds to start. The status bar says Exact geometry: on when it is ready. A mesh does not need it.
If it does not work#
- That does not look like a STEP file. In your CAD program use Export → STEP. The file ends in .step but holds something else.
- That file could not be read as STEP. Export it again as STEP (AP203 or AP214). AP203 and AP214 are kinds of STEP file. Choose one of them if your program asks.
- There are no solid bodies in that file, only surfaces or lines. SchoolCAD tries to sew the surfaces into a solid first. If they do not close up, export a solid body from the program it came from.
- … could not be read as STL (or OBJ, 3MF). The file is damaged or not really that type: export it again.
- This browser has no room left to keep this design. Use Save file, and delete designs you no longer need in Documents.
- An imported file in this design is kept in another browser. The design was copied without its big file. Open it from its saved file instead.