Imported CAD machines

Assign physical roles, inspect preparation and understand route limits.

Printing keeps the current diagram selections and checklist state. Select the views you need before printing or saving as PDF.

On this page

Bring the solids, give them roles Prepare before solving The same pages as a parametric design Know the current limits Check losses separately from torque Review assignments before preparing Save and inspect preparation When preparation cannot continue

CAD IMPORT / ASSIGN → CHECK → PREPARE

From solids to a declared machine.

A conceptual reading aid for the development import workspace. It does not load CAD, prepare a mesh or run a solver.

The segmented tooth has a wider shoe at each axial end. Copper on either side of the stem represents two sections through the same coil; its end turns are outside this section. One rotor is shown. The +z axis points down in this diagram only; check your declared machine frame.

A CAD solid needs a physical role.

In the application: Select solids in the list or 3-D view. Check Rotor iron, Stator iron, Magnet, Coil or Air, then inspect the material and assignment source. Name rules suggest assignments; review their result.
Before continuing: Check that every physical part has its intended role. An unassigned solid is treated as air; that does not mean it is physically air. Keep rotor and stator iron distinct.
Scope of this illustration: This schematic shows representative parts, not a supported CAD file, mesh or complete machine. Colours identify roles, not field strength.

Read the preparation checks → · Compare solver routes →

01Bring the solids, give them roles

Switch Design to CAD import and open a STEP, 3MF, STL or OBJ file. The app reads it with its own reader; no CAD program or kernel is needed. STEP's curved faces are read too, including B-spline, cone, sphere, torus, revolved and extruded surfaces.

Each solid gets a role, by selection or by rules on its name:

iron, with its material;
a magnet, with its material and magnetisation direction;
a coil, with its turns, phase and polarity.

Live checks cover the assignments, the sector, the airgaps and the pole pairs. The import is saved as a project file beside the CAD file.

02Prepare before solving

Prepare is the gate before any solve. It runs on one of three backends:

Structured: the solids are classified onto the native 3-D grid. This is the most complete route.
Tetrahedral: the machine is meshed in pieces, and the mesh is accepted or refused on its quality and topology. The rotor turns on its own mesh.
Quasi-3-D: the solids are cut by cylinders at several radii, and each cut is solved in 2-D.

A refused mesh is reported with its reason. The app does not quietly solve a broken one.

03The same pages as a parametric design

A prepared import uses the same Simulate, Capability and Results pages:

no-load and loaded field solves;
a flux map on its measured d-axes, with the resistance from the coils' own solids;
envelopes, MTPA and efficiency maps, with the losses the route measured.

On the structured route, temperatures, continuous ratings and short-time ratings come from the import's own 3-D thermal model, with uncertainty bands.

04Know the current limits

The structured route has temperatures, a coupled loop and ratings with uncertainty bands. In the development build, loaded tet runs also report temperatures using the shared structured conduction model; the tet route's coupled loop and uncertainty bands remain open. The quasi-3-D route has no temperatures yet. The packaged candidate predates these additions.
The quasi-3-D slices sample no magnets, rotor iron or coil field; their AC copper loss is the strands' skin effect alone.
Coils must be wound round the machine's axis, and rotor iron must be round. Other shapes are refused.
Drive cycles and PWM losses are refused on imports for now.

05Check losses separately from torque

Good mean-torque agreement does not qualify rotor-iron or magnet eddy losses. In the documented AF50 comparison, the default tet gap mesh under-resolves the slot-harmonic field that drives those losses. An accepted preparation mesh has passed its quality checks, not demonstrated convergence of every output.

For a rotor-loss study, check refinement of the gap and conducting regions, and the harmonic sampling used by the loss calculation. Compare the same loss component and operating conditions as those settings change. The structured route remains the reference for that documented comparison; this is not a general accuracy guarantee for either route.

Back to your first machine →

06Review assignments before preparing

Use the illustrated sequence above as a reading aid, not a CAD model to reproduce. Open your imported project in Design → CAD import and select a solid in the list or 3-D view. Review whether its assignment comes from a solid-specific entry or a name rule. Unassigned solids are treated as air; check that a physical part has not been omitted accidentally.

Distinguish Rotor iron from Stator iron and review Material. For Magnet, check Component and Direction (r, θ, z) as well as material. In a purely axial example, (0, 0, +1) and (0, 0, −1) point in opposite axial directions; they are not general settings for every imported machine. Check the project's coordinate frame and actual magnet arrangement.

For Coil, review Component, Phase, Polarity, Turns and Wire area. Multiple solids representing one physical coil need a consistent winding assignment. Select whole coil, where available, helps select its sides and end turns. Polarity +1 or −1 is a winding sign, not the magnetisation vector. Check the winding definition rather than assigning every coil the same sign.

When selected solids have mixed values, an edit can apply one assignment across the selection. Inspect the selection before changing a magnet direction, phase or polarity.

07Save and inspect preparation

Review the machine declaration, backend, sector, pole pairs and airgap locations. Use Save as… for a new import, or Save for edits. The project folder keeps preparation artifacts, and relative CAD paths depend on the saved project location.

Choose Prepare after saving and resolving blocking findings. Read both the job result and findings. Prepared applies to the document that was prepared, not every later edit. Changed since it was prepared means the current document needs preparation again. A prepared import proceeds to Simulate on its selected backend; preparation itself is not a solved field or a validation result.

08When preparation cannot continue

Observation	Check	Next action
Prepare is unavailable	Is the project saved, edited since saving, blocked by findings or already preparing?	Save the current document, read blocking findings and wait for an active preparation job
Assignment or geometry finding identifies solids	Review the named parts, physical roles, material, magnet directions, coil grouping and machine declaration	Correct the reported cause, save and prepare again
The last Prepare refused the import	Read the reason for the selected backend, including geometry, mesh quality or topology requirements	Adjust the input or route only where supported; a refusal is not evidence that another route is suitable
The last Prepare failed	Inspect the job error and logs; distinguish execution failure from an explicit geometry refusal	Resolve the reported cause or draft a support report with the exact message
Changed since it was prepared	Compare the current document with what was prepared	Save and prepare the changed document again

Do not hide a blocking finding by reclassifying a real component as air or dropping it from the physical model. Keep the original CAD and saved project while investigating. If needed, draft an application report with the selected backend, preparation state and exact message, excluding private CAD unless you choose to share it.

This guide follows the development import workspace. Release status distinguishes packaged availability; successful preparation does not remove the route limits described above.