Start with Walter’s heat.
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Recorded from the existing physical setup. This is not a live feed or a test inside the unprinted helmet. Room temperature and installed cooler are not yet documented.
Each point comes from the Pi sensor. No synthetic warm-up curve is mixed into this recording.
What we measured
What remains unknown
Total input power, USB/peripheral loads, ambient and local air temperature, heatsink contact, shell temperature, and battery temperature. PMIC rail output does not measure the whole system.
Fan RPM shows that the fan is turning. It does not measure the air leaving the helmet.
Inspect the calculation. Keep its limits visible.
Cooling design & whole-build test lab ↗
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| Helmet mesh | Air cells | Quality result |
|---|
The mesh is the small volume cells used for numerical calculations. These cells are separate from the smooth printable shell. A failed mesh is not an accepted airflow prediction. The preliminary2.5mm cells span only about1.6 cells across nominal4mm vent slots; the0.4mm crown seam is smaller than a cell. Those passages need better resolution and a specified treatment of joint leakage.
Independent heat-and-buoyancy reference test
This is a tall heated cavity supplied with OpenFOAM, compared with the accompanying Betts–Bokhari experimental profiles. It is not Walter’s head, fan or thermal calibration.
Dots: experimental measurements. Line: numerical solver. Errors remain visible; the curves are not fitted to hide disagreement.
Official reference case ↗Published hardware evidence
Numbers below keep their original meaning: a workload reference, standard consumption or amplifier output is not automatically a maximum heat load.
| Component | Electrical input evidence | Meaning and remaining measurement |
|---|
Before a temperature or airflow prediction earns trust
The rear-facing Pi changes the airflow problem. The original R07 comparison cannot be used to approve R08. The manufacturer’s cooler test was performed in open air; it does not establish Walter’s enclosed temperature.
Open the separate assumption calculator ↗Its CPU-temperature prediction has been withdrawn. Its mixed-air and fan calculations require an explicit opt-in and remain uncalibrated comparisons.
Where the reference numbers come from
Raspberry Pi’s thermal bench tests · Pi5 workload power reference · Pi sensor and power documentation · Download the evidence register