Capture the complete trajectory
Provide a sequence of positions or a motion model that includes travel, changing curvature, twist, nearby surfaces, and endpoint rotation. Record rate, dwell, environment, and required service exposure. Use mechanical models to communicate the path, but identify the physical constraints that create it. A model showing one attractive folded position leaves most of a dynamic problem unresolved.
Dynamic design evidence map
| Requirement | Design record | Verification focus |
|---|---|---|
| Motion path | Positions, restraints and free span | Observed shape throughout travel |
| Electrical duty | Active nets and meaningful failure thresholds | Continuity or resistance during motion |
| Construction | Regional materials and copper arrangement | Sample conformity before testing |
| Environment | Operating and storage exposures | Representative combined conditions |
Control where movement happens
Decide which span is intended to deform and how its ends are supported. Review friction, free length, shields, and local thickness changes together. Apply the strain-relief workflow at load entry points and inspect conductor paths through the active span. A layout change that moves a reinforcement edge can change the motion even when the overall outline stays the same.
Make the prototype answer a reliability question
Create a bend test specification before ordering representative samples. Define the actual fixture, monitoring method, interruption criteria, and post-test examination. Preserve a construction record for each sample so a promising result can be reproduced. If a failure appears, retain its position and history rather than immediately increasing thickness or changing several variables at once.
Before you release the design
- Include startup, reversal, dwell, and service handling in the motion description.
- Check enclosure contact in all operating positions.
- Specify how intermittent electrical events will be captured.
- Tie every tested sample to its material and drawing revision.
Watch points
- Do not assume a static fit check represents moving-service duty.
- Changing the fixture can invalidate comparisons between otherwise identical samples.
Practical questions
Can a material datasheet supply the required cycle life?
A material result describes its specimen and conditions. Use it as selection context; verify the finished assembly with its actual construction, support, movement, and environment.
Should I add slack to improve endurance?
Evaluate free length with the mechanism. Additional length can alter curvature or introduce rubbing and buckling. Observe and test the resulting path rather than treating slack as a universal solution.
Technical references
References support the material or design context. Check the exact grade, part number, document revision and project conditions before release.Updated 27 September 2026 · Technical content policy · Engineering guidance supports project review; the agreed drawing defines the build.