Trace Mechanical designs a 3D-printable case around your real board. Ask the assistant for an enclosure and it builds a base and lid with openings where your connectors face, posts under the mounting holes and room for the tallest parts, then checks that everything fits, plugs in, goes together, prints well and stays cool enough.
New in Trace 3.2 and Trace Plugin 2.0. The app and the plugin use the same engine, so the same board gives the same case.
What It Makes
- Cases made by 3D printing: filament (FDM) and resin printers.
- A base and a lid, plus small printed parts such as light pipes and button plungers.
- Print files (STL, 3MF) and CAD files (STEP, GLB, DXF, IDF).
It does not design cases for injection moulding, CNC machining or sheet metal.
Before You Start
- Trace app: open the project and its board.
- Trace Plugin: link the plugin to the board open in Altium Designer, KiCad or Autodesk Fusion.
- Give the case real part heights. Parts with 3D models are used as they are; see Part Heights and Heat for parts without one.
- Mounting holes help. A board without them rests on ledges along its edges instead.
Ask for a Case
- Open the chat in Agent mode.
- Describe the case you want: how the lid closes, which connectors and buttons must be reachable, and anything else from the list below.
- The assistant writes the case, builds it, reads the check results and shows the case on the Mechanical page.
- Look the case over on the Mechanical page, then ask for changes in the chat or edit a feature yourself.
Example requests:
Design a 3D-printed case for this board with a snap-on lid.
Leave the USB-C and the JST connector reachable, and add a light pipe for D1.
Make the case wall-mountable with keyhole slots, add vents over U3,
and give the lid a groove for a seal.
Add a plunger for SW1 through the lid and four rubber-foot recesses underneath.
Case Options
| You can ask for | What you get |
|---|---|
| Lid closure | Screws (M2 to M5, into heat-set inserts, self-tapping or nuts), snap catches, a friction fit, a printed hinge, or a sliding lid |
| Seal | A groove in the walls for a silicone cord the lid presses. Splash-proofing only; Trace gives it no rating |
| Buttons | Holes and printed plungers |
| LEDs | Holes or printed light pipes |
| Air | Vent slots or holes, or a grille and screw holes for a 25, 30, 40, 50 or 60 mm fan |
| Feet | Printed feet or recesses for rubber feet |
| Wall mounting | Screw ears or keyhole slots (M3 to M5) |
| Parts that stand out | Openings for parts that stand out through the lid, such as a shaft or antenna |
| Connectors | An opening where each connector faces, sized for it and its plug, including USB-C, JST, Qwiic, flat flex and screw terminals |
| Boards without holes | Ledges along the board's edges, with ribs from the lid holding it down |
A sliding lid can't be combined with screws, snaps or a hinge, with a ledge mount, or with a wall whose opening reaches the lid's slot. The assistant tells you when a choice clashes.
Open the Mechanical Page
| Where | How |
|---|---|
| Trace app | The Mechanical button beside Simulation at the top of the window |
| Trace app | Tools > Mechanical in the main window, or View > Mechanical in the board editor |
| Trace app | Double-click a case file (.trace_mech) in the project tree |
| Trace Plugin | The Mechanical cases button at the top of the chat opens the Mechanical window |
The menus show in the Full layout; on a Mac the menu bar is always there. The assistant also opens the page on the case it is working on.
The page opens on the case the assistant last built, on your only case, or on the list of your project's cases, newest first. All cases at the top brings the list back. With no case yet, press Ask Trace to start one, or New case in the list to add another.
In the Trace app, each open project has its own Mechanical tab, which comes back with the same case and view.
Use the Mechanical Page
Top of the page
- All cases: the case list, with each case's check results and exports.
- Open spec: opens the case's text description, which you can edit by hand.
- Rebuild: builds the case again. A notice appears when the board or the case changed since the last build.
- Export: the export menu (below).
3D view tools
| Tool | What it does |
|---|---|
| Fit to view and Iso | Frame the whole case, or look from the front right, above |
| XYZ marker | Click an axis on the turning marker in the corner to look from that side, including underneath |
| Lid and Board & parts | Show or hide those groups in one click |
| Show | Hide any group or a single part, such as the light pipes or one chip. Hide selected and Show all are in the same menu |
| Heat | Colour each part by the heat it gives off, with a legend |
| Explode | Take the case apart in assembly order: the base stays, the board lifts out with its parts and plugs, light pipes, plungers and fans float above it, and the lid comes off last |
| Section | Cut the model at a height you set |
| Measure | Click two points to measure between them. Esc cancels |
Measure and Section are off while the case is exploded, and Explode is off while the heat view is on.
Side panels
- Statements (left) lists every feature of the case, one line each.
- The inspector (right) shows the Checks, the Properties of what you selected, the Hardware to buy (screws and inserts), and a summary of the printed parts and openings.
Change a Feature
- Pick a feature in Statements, or click a part in the 3D view.
- Change a value in Properties. The case rebuilds and the checks run again.
- Or press Ask Trace about this to take the feature to the chat and describe the change there.
Your edits are saved to the case, and the assistant sees them the next time it looks.
The Checks
Each case shows six checks. Click a finding to see it in 3D. Every finding names the change that fixes it.
| Check | What it looks at |
|---|---|
| Fit | Parts overlapping the case or each other |
| Clearance | Room between each part and the case, and parts taller than a height limit on the board |
| Access | Whether each plug can go in all the way, past the case, other plugs and the room around it |
| Assembly | Whether the board drops into the base and the lid closes over it |
| Printability | Thin walls, bridges, overhangs and bed contact, which printers can take the parts, and printing tips |
| Thermal | A rule-of-thumb temperature for a closed box, compared with the material's softening point |
The thermal check is an estimate, not a thermal simulation. Check the printed case on the real board before you rely on it.
Export the Case
- Press Export. STEP and STL are ticked by default.
- Tick the formats you need, then press Export N formats.
- To open the folder, press Show exported files in the same menu.
| Format | For |
|---|---|
| STEP | Your mechanical CAD tool: the whole assembly, with names and colours |
| STL | Your 3D printer: each printed part, laid flat and centred |
| 3MF | Your slicer: every printed part set out on one plate |
| GLB | Viewing and sharing: the whole scene as shown |
| DXF | What the case asks of the board, in 2D |
| IDF | The same, for ECAD tools |
Files go in the mechanical/exports folder of your project. Each case itself lives in the project's mechanical folder; keep that folder with your project. Trace also keeps a cache folder there, which is safe to delete.
You can also ask the assistant to export, for example "Export STL and 3MF for printing".
Print the Case
Trace makes print files, not printer instructions. Open the STL or 3MF files in your usual slicer, choose your printer and material there, and slice as usual.
- Each STL lies flat and centred, ready to drop on the bed.
- The 3MF sets out every part on one plate, sized for the smallest common printer bed that takes them all, and names the parts as your slicer lists them (base, lid, light pipes).
- Printability says which printers can take the parts and gives tips, such as a brim for tall thin parts or tilting the base and lid 30 to 45 degrees on a resin printer.
- Tell the assistant which printer you have, or its bed size, and it checks every part against that bed, turning a part when that is the only way it fits.
Part Heights and Heat
The case is sized from your parts, so their heights matter.
- 3D models: a part with a 3D model is used exactly as it is.
- Height field: without a model, Trace uses a Height field on the part (also IDF_HEIGHT, Component Height or Max Height).
- Package estimate: otherwise the part is sized from its package, and the checks name it as an estimate.
In the Trace Plugin, parts come from Altium's 3D bodies, KiCad's 3D models and Fusion's 3D packages.
For heat, add a Dissipation field to the parts that get warm (in watts; Power Dissipation, POWER_OPR and Heat also work), or tell the assistant how much each part gives off. A field named Power is ignored, because it is usually a rating. Heat stays off until at least one part's heat is known.
In the Trace app, File > Export > IDFv3 writes each part's real height and heat for other CAD tools too, and File > Import > IDFv3 Board keeps them.
Plan the Case Before the Board
In the Trace app you can design the case first and lay the board out to fit it.
-
Tell the assistant the size the product has to fit and the connectors it needs, for example:
Before we lay out the board, plan a case that fits within 60 x 40 x 25 mm, with a USB-C on the bottom wall and a JST-PH on the right wall. -
A plan card shows the board size, the mounting holes and the room left for parts.
-
Press Use this to lay the board out to that plan, Adjust to change it on the Mechanical page, or Skip to go on without it.
With Use this, the board gets its outline, corner mounting holes, height limits above and below, and each connector placed at its opening. Without a board size, the board becomes the largest that fits the case. Once the board is laid out, ask for the case to be built around the real board.
The plan card is not in the Trace Plugin yet.
Keep the Board and Case in Step
Once a case exists, the assistant's board checks warn you when:
- a connector moves away from its opening;
- a part lands where a case post stands;
- the board outline changes from the one the case was built for;
- a part becomes too tall for the lid.
After board changes, open the case and press Rebuild, or ask the assistant to update it.
Cases in Autodesk Fusion
Trace Plugin 2.0 builds cases for Fusion Electronics designs too, around each part's real 3D package. If the design has no 3D PCB yet, the plugin makes one with Fusion's own command.
Ask the assistant to open the case in Fusion. It goes into a new 3D design beside yours in the hub, around a linked copy of your 3D PCB that follows the board. Asking again replaces the case as a new version. See Autodesk Fusion.
Cases in Team Workspaces
Cases are part of your project, so they commit, push and branch with it. When teammates change the same case on different branches, Workspaces merges it feature by feature. Where both sides changed the same feature, the assistant works out the merged version from what moved on the board, and you review it before you apply. See Branches.
If Something Looks Wrong
- Nothing was built: the engine stopped before it made a part. Press Show statements and read the messages on the marked lines, or ask the assistant to fix them.
- Spec has an error: a line in the case could not be read. Open the case and look for the marked statement.
- A part is shown as an estimate: add its 3D model or a Height field, then rebuild.
- Heat is greyed out: no part's heat is known yet. Add Dissipation fields or tell the assistant.
- The case no longer matches the board: press Rebuild on the notice at the top of the page.
Print a test part first, such as the lid, and check it against the real board before you print everything.