Large assemblies
Look around a very big STEP file, such as a whole robotics robot, then open any part from it as an exact solid.
A STEP file of a whole machine can be hundreds of megabytes. A robotics team's robot, for example, can have hundreds of different parts and thousands of screws. That is too much to open as exact solids in a browser, so SchoolCAD opens a STEP file over 30 MB in the Large assembly view instead. It is view only: you can turn it, zoom, hide parts, look inside with a section and take it apart with Explode. Then you can open any single part from it as an exact solid, to measure it, sketch on it or design around it.
Nothing is uploaded. The file is read on your own computer, in the background, so SchoolCAD keeps working while the parts appear one by one.
How to use it#
- Open file (or drag the file onto SchoolCAD) and choose the big STEP file.
- The left side shows how many different parts the file has, how many are placed, and how many of those are fasteners (screws, nuts, washers and rivets). The bar shows how many parts are ready.
- Turn and zoom the view as usual while the rest of the parts appear.
- Click a part to select it. The box in the corner shows its name and how many times the assembly uses it.
- To work on that part, click Open part (a new design with just that part, exact) or Add to design (adds it, exact, to the design you had open).
Options#
| Option | What it does |
|---|---|
| Fit | Shows the whole assembly. |
| Show all | Shows every part again after Hide or Isolate. |
| Shaded with edges, Shaded, Hidden lines | How the parts are drawn. |
| Y up, Z up | Which way is up. SOLIDWORKS, Inventor, Fusion and Creo save files with Y up; Onshape and SchoolCAD use Z up. SchoolCAD guesses from the file: change it if the model lies on its side. |
| Section X, Y, Z | Cuts the view along that axis. Drag the slider to move the cut. |
| Explode | Moves the parts apart so you can see between them. |
| Show screws, nuts, washers and rivets | Fasteners are often half of everything placed. When there are a lot, they are left out at first so the view stays quick. Tick it to load them. |
| Select all, Zoom to, Hide, Isolate | For the selected part. Isolate hides everything else. |
The Parts list on the left is the assembly's own tree. Click a subassembly to select all of its parts, or double-click it to zoom to it.
Tips#
- Every copy of a part shares one shape, so 400 identical bolts take no more memory than one.
- A very big file can take a few minutes until every part is shown. A computer with more processor cores is quicker.
- Click while holding Shift or Ctrl to select more than one part. Esc clears the selection, and then closes the view.
If it does not work#
- This STEP file only points to other files. It was saved with each part in a file of its own. In your CAD program, export the assembly again as a single STEP file.
- There was not enough memory on this computer to read it. Close other tabs and try again, or export the robot in smaller subassemblies.
- Some parts could not be shown. Their names are listed on the left. The rest of the assembly still works. Export those parts again, or open them on their own.
- The model lies on its side. Change Y up to Z up, or the other way round.