STEP workflows: moving between Solid Vibes and other CAD

STEP is the lingua franca of mechanical CAD. It carries exact solid geometry, so faces stay faces and arcs stay arcs. This article covers the practical workflows, plus what STEP does and does not carry.

What travels in a STEP file

A STEP file is a snapshot of shape, not of how it was made. This is true in every direction: STEP from SolidWorks arrives in Solid Vibes without its feature tree, and STEP from Solid Vibes arrives in SolidWorks as a dumb solid.

Bringing a part in

1. Import the STEP (IGES also works for solids). It is placed as a body in a piece, using an Import step with a position and rotation.
2. Check units and size. Everything inside Solid Vibes is in millimetres. Verify the bounding box against what you expect. Ask: "What is the overall size of this body?"
3. Orient it. Z is up and the XY plane is the bed. Rotate with a Transform if it landed on its side.
4. Build on it. Add features with the usual steps:
   • cut holes and pockets with Boolean cuts or Hole steps,
   • add fillets and chamfers to edges you select,
   • add bosses, ribs and brackets as new bodies and union them.
5. Name parameters for your additions. The imported body itself is fixed, but anything you add can be parametric.

Selecting on imported geometry

Imported bodies have no creation history, so selectors cannot use createdBy. Use geometric ones:

• normal or parallelTo for planar faces,
• extreme for outermost faces,
• radius and surface for cylindrical holes and bosses,
• nearest or containsPoint for a specific location.

Pick in the viewport and Solid Vibes builds a suitable selector for you. See Selectors and topological naming.

Mesh formats are different

STL, 3MF and OBJ are triangle meshes. They are fine as reference geometry or for boolean operations, but smooth-surface features (fillets, shells) work best on real solids from STEP. If a mesh is all you have, build a clean Solid Vibes model next to it, using the mesh as a visual guide.

Sending a part out

1. Export STEP.
2. Check in the receiving CAD that the units, size and orientation are right.
3. If a shop is involved, also send a PDF drawing with dimensions and tolerances. See Drawings for a CNC shop.

For an assembly Thing

A Thing with several pieces can be sent piece by piece or as a whole. Open the result in your CAD and check that:

• the pieces are separate bodies (or components) as you expected,
• bought pieces such as screws arrived at their correct positions,
• nothing is duplicated.

When in doubt, export the pieces you need individually.

Round-tripping

Practical tips

• Simplify before importing. Remove tiny cosmetic details, threads and fasteners you do not need. Large imports are slower and noisier.
• Prefer solids over surfaces. A closed, watertight solid behaves well. Open surface models may need repair first.
• Heavy files are processed on the server with a high-fidelity kernel, so very large STEP files can take longer than small ones.
• Check for a stray reference body. Some exports include construction geometry, which you can suppress.
• Keep vendor models separate. Bring supplier STEP files in as their own pieces rather than merging them into a piece you are designing.

Try it

I just imported a STEP of a motor mount. Tell me its bounding box and the diameters of its round holes. Then add four M4 clearance holes 5 mm in from the corners of the largest flat face, as new parametric features on top of the import.

Notice that your holes are parametric, and the imported body stays fixed.