The problem
Charging connectors are handled thousands of times by users with different hand sizes, often in rain or dark car parks, and heavy DC cables make them tiring to hold. The mating face is fixed by standards, but the handle shape, latch and cable exit are design choices that decide comfort, robustness and ease of use.
Objectives
- Collect anthropometric hand data and define grip size targets.
- Sketch and surface a grip form in Alias around a fixed mating face envelope.
- Detail the shell parts, latch mechanism and cable exit in SOLIDWORKS.
- Check strength under misuse loads and estimate drop robustness.
- Test hand fit with a 3D-printed model and refine.
What you need
Tools and toolboxes
- Autodesk Alias — Grip form from sketches with Skin and Rail surfaces, checked with Zebra and curvature evaluation.
- SOLIDWORKS Part and Assembly — Imported grip surfaces thickened into two shells, latch, spring and cable boot.
- SOLIDWORKS Simulation (Static) — Latch and housing stress under misuse loads such as pulling on the cable and dropping.
- SOLIDWORKS Motion or Mates — Latch movement with Limit Angle mates or a simple Motion Study to check travel and clearance.
- 3D printing — Hand-fit prototypes for user testing.
Software
- Autodesk Alias 2024 or later
- SOLIDWORKS 2023 or later
Extra parts and data
- Anthropometric hand data for the target population — Hand length and grip diameter percentiles set the handle size; Indian data from published sources is preferred.
- 3D printer access — Printed handles are needed to test grip with real users.
Key concepts
- Mating face envelope
- The connector's mating geometry is defined by standards such as IEC 62196 for Type 2 and CCS2. The handle design must keep this interface unchanged.
- Grip diameter
- The handle cross-section a hand wraps around. Too large or too small reduces grip strength and comfort; it is chosen from anthropometric percentiles.
- Wrist neutral posture
- A handle angle that keeps the wrist straight during insertion reduces strain and effort.
- Latch
- The mechanical catch that holds the connector in the inlet. Its release must be easy to operate but resist accidental release.
Step-by-step guide
- 1
Define users and requirements
Choose a connector type, for example a CCS2 DC connector for a car or a smaller connector for a two-wheeler. Gather hand anthropometric data for the target population from published sources, and pick a design range such as 5th percentile female to 95th percentile male. Define requirements: grip diameter range, handle angle, latch force feel, cable mass supported, glove use and rain shedding.
Checkpoint: A requirement table with anthropometric ranges and target grip dimensions.
- 2
Model the mating envelope
Model the mating face and its envelope as a fixed reference body in SOLIDWORKS from the standard's published outline, or a simplified example if the full standard is not available, and say which. Include the latch position and cable entry. Export it as STEP to Alias so the grip is built around a fixed interface. Make the envelope a separate part that is never edited, and mate all handle parts to it so the interface cannot drift.
Checkpoint: A reference body with the mating face and latch position, labelled as standard-derived or simplified.
- 3
Sketch grip concepts
Sketch at least four side views around the envelope, varying handle angle, trigger position and cable exit. Consider insertion: the user pushes along the inlet axis, so the handle angle should let the wrist stay straight. Consider resting the connector in a holster. Pick two concepts to make quick foam or printed blocks of for an early feel test. Photograph users holding the blocks so you can later compare hand postures between concepts and explain your choice.
Checkpoint: Two concepts tested as rough blocks with a few users, and one chosen with reasons.
- 4
Surface the grip in Alias
Import the envelope and scaled sketches, draw section curves of the grip at intervals and the side silhouette. Build the grip with Skin or Rail surfaces, keeping a simple CV structure. Blend into the nose around the mating face with Surface Fillet. Check with Zebra and Curvature Evaluation and use Align to get G2 on visible blends. Keep the grip cross-sections slightly oval rather than round, which resists twisting in the hand, and check them against your target grip size.
Checkpoint: Grip surfaces with smooth zebra stripes and G2 continuity on the main blends.
- 5
Export and build shells
Export the surfaces as STEP to SOLIDWORKS, knit them and thicken inward to a wall of an example 3 mm to make a solid, then split into two shells along a parting line that avoids the grip area. Add Lip/Groove, screw bosses and ribs. Check draft with Draft Analysis for the moulding direction of each shell. If Thicken fails at tight curvature, return to Alias and relax that area rather than patching in SOLIDWORKS, so the master surface stays clean.
Checkpoint: Two shells that close with a clean split, draft on all walls and no gaps.
- 6
Design the latch
Design the latch lever with a pivot pin, a return spring and a thumb or finger button positioned so a gloved user can reach it from the grip. Use Limit Angle mates or a Motion Study to check its travel and that it clears the shell. Estimate button force from the spring rate and lever ratio, aiming for a stated range.
Checkpoint: Latch travel and clearance shown in motion, and a calculated button force within the target range.
- 7
Design the cable exit
Design the cable exit at the back of the handle with a clamp inside and a tapered flexible boot outside to control bending. Position the exit so the cable weight hangs naturally and does not twist the wrist. For heavy DC cables, consider an exit angle that brings the cable down rather than straight back. Add a configuration with the cable at its heaviest angle so the assembly shows the worst-case hang during insertion.
Checkpoint: Cable clamp and boot modelled, and the cable hang direction shown in the assembly.
- 8
Check strength
Run static studies on the shells and latch: a cable pull load, a side load on the nose as if the connector is levered in the inlet, and the latch holding force, all with example values. Use contact between shells and bolt connectors for screws. Refine mesh at latch pivot and boss roots. Treat a drop case as an equivalent static impact if Drop Test is not licensed.
Checkpoint: Factor of safety above a target such as 2 in all load cases, with mesh convergence on the latch pivot.
- 9
Print and test grip
Print the two shells at full size and assemble them with a weight inside to match the connector and some cable. Ask several users with different hand sizes to hold, insert into a mock inlet and release the latch. Record comfort ratings and observations. Adjust grip diameter, angle or button position and print a second version. Use the same short rating questionnaire for both versions so the scores can be compared directly between rounds.
Checkpoint: User feedback from at least five people, with changes made and a second version tested.
- 10
Drawings and report
Produce drawings of shells, latch and boot with key dimensions, materials and general tolerances, and an assembly drawing. Render the final handle in KeyShot, VRED or SOLIDWORKS Visualize. Write a report linking each design choice to anthropometric data or test feedback, and state that conformity of the mating face to the standard must be checked separately. Include photos of users holding the printed prototypes next to the CAD images, so the ergonomic choices are easy to follow.
Checkpoint: A drawing set, renders and a report with ergonomic evidence and standards caveats.
Testing & validation
- Grip size is justified by anthropometric percentiles.
- Zebra and continuity checks pass on the grip surfaces.
- Latch travel and button force are checked.
- Strength studies meet factor of safety targets with converged meshes.
- Printed prototypes are tested by users with different hand sizes.
Expected results
A charging connector handle design with an Alias grip surface, SOLIDWORKS shells, latch and cable boot, strength checks and user-tested printed prototypes, documented with drawings and renders.
Take it further
- Add a torch or status LED and a lens to the nose.
- Design a matching holster for a charger kiosk.
- Compare two grip angles with a structured comfort rating study.
Viva and review questions
Why not change the mating face to improve the grip?
The mating face is fixed by the connector standard so it works with every inlet. All the design freedom is in the handle, latch and cable exit.
How did you choose the grip diameter?
From hand anthropometric data for the target population, covering a range from small to large hands, then refined it with printed prototypes and user feedback.
Why does the cable exit angle matter?
A heavy cable creates a moment on the handle. Bringing it out downward reduces the twisting load on the wrist and makes insertion easier.
Learn it at DIYguru
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