For Design for Manufacture, my team made an aluminum box that utilizes
a flexure to have a twist-to-lock feature. When in the "open" position, the two halves
of the box have a running fit and come apart easily. Twisting the halves so that they
align deflects a flexure that snaps into the "closed" position, locking the halves
together.
My contributions and experience gained include:
- Fatique Analysis with S-N curve
- Beam bending calculations to validate FEA analysis of flexure
- HSMworks CAM - Tolerancing force fits
- Designing to promote high material removal rate and decrease cycle time
- Cost analysis
Toolpaths from HSMworks CAM
Stress plot from FEA analysis of flexure. Max stress is below the stress that
causes fatigue failure after 1,000 cycles.
The team de-risked the flexure design through prototypes in PLA and aluminum. These
prototypes behaved as the calculations and FEA predicted, validating our modeling
assumptions. The final, complete version of the box works great: it is easy to open
in the "open" position, and stays closed against gravity in the "closed" position.
