How Robotics Hardware Leads Run DFM Reviews Before DVT

A DFM review for robotics hardware works when manufacturability feedback stays on the 3D geometry, shows up in the designer's CAD session, and links to the requirement it affects. It fails when the same feedback leaves the review as email threads, slide decks and PDF markups.

This article follows one robot actuator housing into DVT. It shows what suppliers and manufacturing engineers flag, where that feedback gets lost, a DFM review checklist you can run, and how leading teams keep findings attached to the design until they are closed.

Why the DFM review before DVT decides the build

The DFM review before DVT decides the build because DVT is the first build where tooling, supplier process capability and the design meet at volume-representative conditions. Every manufacturability issue you don't close before that build becomes a tooling change, a scrapped lot or a schedule slip.

For robotics and physical AI hardware, the stakes sit in the mechanical design. Actuator housings, arm links and gearbox covers carry structural load, shed heat from motors and drivers, and hold bearing and gear alignment. A wall that is too thin for the casting process is also a stiffness and thermal path problem. A DFM finding is rarely only a manufacturing finding.

So the review can't be a meeting that ends with a deck. It has to produce changes to geometry and updates to requirements, and it has to leave a record the next build can read. For the build-by-build view of how requirements should move through EVT, DVT and PVT, see EVT, DVT, PVT: Keeping Requirements Straight Across Builds.

The actuator housing walkthrough: what suppliers and manufacturing engineers flag

Picture an actuator housing heading into DVT. The designer has frozen the geometry to hit a torque and mass target. Then the supplier and the manufacturing engineer open the model, and the findings start.

The typical flags fall into a few groups:

• Draft angles. Internal walls and bosses with too little draft will drag on ejection or pull from the mold. The fix is small, but it moves wall thickness and can shift a bearing seat.

• Wall thickness. Thin sections risk short fills in casting or molding, and thick sections risk sink and porosity. Wall thickness is also a structural stiffness input and a thermal conduction path from the motor to the outer surface.

• Tool access. A pocket the cutter can't reach, or a bore that needs a special fixture, adds cost and cycle time. Sometimes the answer is a split part rather than a tweak.

• Fastener stack-ups. Boss heights, thread depths and clamp surfaces that look fine nominally can fail once tolerances stack. That affects preload, sealing and the alignment of the output stage.

• Thermal and structural risk. A rib removed to ease machining may drop stiffness under the load case, and a thinned wall may raise the motor winding temperature.

None of these findings is exotic. Each one points at a specific feature on a specific part, and each one touches a requirement: a mass limit, a stiffness target, a temperature rise, a seal spec. A finding that loses its location or its requirement link gets re-discovered at the next build.

Where DFM feedback goes to die: email, slide decks and PDF markups

DFM feedback dies in the gap between where it is given and where the design is edited. The supplier marks up a PDF export. The manufacturing engineer replies to an email thread. Someone pastes screenshots into a deck for the review meeting. Each of those artifacts is detached from the CAD model.

Three things break once feedback leaves the geometry:

1. Location drifts. A screenshot of a rib with a red circle doesn't survive a design revision. After two rev changes, nobody can say which rib the comment meant.

2. The requirement link disappears. The note says "increase wall to 3 mm." It doesn't say the wall is also the thermal path for a motor temperature requirement, so the designer fixes one problem and quietly opens another.

3. The designer never sees it where they work. The designer lives in the CAD session. A comment in a mailbox or on slide 14 competes with everything else in the day, and it loses.

The result is predictable. The same draft-angle or tool-access issue appears at the next build because the first finding was never closed against the geometry. If your DFM log is a folder of PDFs, you don't have a log. You have an archive.

The same discipline governs any controlled change. The change control board guide covers how to disposition changes once they are proposed. DFM feedback needs to reach that process in a form that carries its location and its reason.

A DFM review checklist for robotics hardware

A usable DFM review checklist for robotics hardware is short enough to run in one session and specific enough to produce changes. Run it against the actuator housing, then against every other load-bearing or heat-bearing part going into DVT.

• Process fit. Has the supplier confirmed the process (casting, machining, molding, additive) against the actual geometry, not an earlier concept?

• Draft and parting. Are draft angles and parting lines agreed for every cast or molded surface?

• Wall thickness range. Are minimum and maximum walls inside the supplier's capability, and have you checked what they do to stiffness and to the thermal path?

• Tool and fixture access. Can every feature be reached and held without a special fixture the program hasn't budgeted?

• Fastener and tolerance stack-ups. Do boss heights, thread engagement and clamp faces hold across the tolerance range for the joints that carry load or seal?

• Structural check. Does any removed or thinned feature reduce stiffness below the requirement under the governing load case?

• Thermal check. Does any change reduce the conduction path or surface area that the motor temperature requirement depends on?

• Failure modes. Does each manufacturability risk appear in the design FMEA with a link to the requirement it threatens? See the Design FMEA guide.

• Ownership and closure. Does every finding have an owner, a geometry location and a closing action before the DVT build release?

Teams skip the last item. A checklist that ends in a list of opinions isn't a review. Every row needs a disposition.

Design review software: keeping manufacturability feedback on the geometry

Good design review software for hardware keeps manufacturability feedback on the 3D geometry, in front of the person who will change it, and linked to the requirement it affects. Most review tools only do the first part.

Tandem is the context layer for hardware engineering: an AI-native platform that connects design intent, requirements, CAD changes, design reviews and validation evidence in one system. Its Design Reviews module is a browser-based 3D viewer that needs no CAD license, so a supplier or a manufacturing engineer can open the housing without installing anything. They place annotations directly on the geometry, reply to each other, mention colleagues, and get Slack link previews.

The next step is what matters. Tandem surfaces those annotations inside the designer's CAD tool through its Annotations function, and it links them to the related requirements. The designer sees the draft-angle comment on the actual face, in the session where they will fix it, next to the requirement it touches. Tandem works inside SolidWorks, Onshape, CATIA, NX and Fusion through a direct plugin.

Tandem is not a CAD application, and it doesn't replace one. It is the layer that keeps review feedback and design intent attached to the model. For a wider look at what to require from review tooling, see our guide to design review software for hardware teams. Adoption is modular, so a team can start with design reviews alone and add requirements, change tracking and PDM later.

From supplier markup to requirement to design change before DVT

The workflow that works before DVT is a chain with no breaks: supplier markup, requirement, design change, closed finding. Here is how it runs on the actuator housing.

1. Markup on geometry. The supplier opens the housing in the browser viewer and flags the thin wall near the motor pocket. The manufacturing engineer adds a tool-access note on the bearing bore. Both sit on the faces they describe.

2. Linked to requirements. Each annotation is linked to the requirement it touches: the motor temperature rise for the wall, the bearing alignment tolerance for the bore. The thermal and structural stakes are visible before anyone edits anything.

3. Visible in the designer's CAD session. The designer sees both annotations in the CAD tool, on the geometry, with the requirement links. Tandem's agents can also review the part for manufacturability and help the engineer judge faster which findings are real risks.

4. The change is captured. The designer thickens the wall and adds draft. Tandem's Design Changes view shows a before and after 3D CAD diff with a plain-language summary, plus the affected requirements and annotations. Requirements that depend on live attributes, such as mass from CAD or a thermal number held in Excel or Google Sheets, are verified against those values continuously.

5. Documentation follows. Tandem generates the ECO, ECN and engineering documentation from the captured CAD changes, in the team's own templates, so the change record doesn't depend on someone retyping it.

The finding closes against the geometry and the requirement, not against a meeting. If you run Teamcenter or 3DEXPERIENCE, Tandem runs alongside it through integrations built during deployment. The handoff discipline after DVT is covered in Design Transfer to Manufacturing: Keeping the Verified Design Intact.

AI tools for mechanical engineering in DFM reviews

AI tools for mechanical engineering earn their place in a DFM review when they work from the program's context, not from a bare model file. A manufacturability opinion with no knowledge of the load case, the thermal budget or the requirement behind a wall thickness is a guess with good grammar.

Tandem's agents can review parts for manufacturability themselves and help engineers judge manufacturability faster and better. The platform already holds the requirements, the CAD changes and the review annotations, so the agents work against the same record the team does. They can also search and update architecture nodes, requirements, attributes and annotations, and run impact analysis when a change lands.

Use AI to widen the first pass, not to replace the supplier. The supplier knows their process window, and the manufacturing engineer knows the floor. The AI pass should surface candidate issues early so the human review spends its time on the hard calls: the rib you can't remove, the wall you can't thicken, the bore you can't reach.

Conclusion

The DFM review before DVT is only as good as the path a finding travels from supplier to geometry to requirement to design change. Keep that path on the model, and the same issue stops coming back at the next build. If your actuator housing is heading into DVT, book a Tandem demo and walk through a supplier markup landing in the designer's CAD session, linked to its requirement.