Mechanical Standards
The mechanical conventions for panels and mounts. Some of this is settled (screws, gauge sizes); panel-level dimensions are still being worked out and are marked TBD — don't invent them.
Screws
| Screw | Use | Clearance |
|---|---|---|
| M2 | PCB mounts, small standoffs | — |
| M3 | Placards, light rings, small brackets | — |
| M4 | Instrument bezels, gauge mounts | Ø4.3–4.5 mm |
| M5 | Panel-to-subpanel, corner mounts | Ø5.3–5.5 mm |
Gauges
| Gauge | Size | Drive |
|---|---|---|
| LOX gauge | 2-5/8″ (~67 mm) | — |
| Radar altimeter | 3-1/8″ (~100 mm with bezel) | — |
| Cabin pressure | — | X27.589 Switec stepper, shaft-through-PCB mount |
Switches & controls
- Toggle switches: 12 mm standard; ~6 mm on the ECM modules.
Panel dimensions, cutouts, bezels, light rings
TBD — driven by the CAD models
Panel outline dimensions, switch/gauge cutout templates, bezel profiles, and light-ring geometry come from the Fusion/FreeCAD panel models, which are early-stage. These will be documented here as panels are modelled. CAD tooling is still under evaluation — see CAD Workflow.
Board-level placement
Mechanical placement on the PCB itself — LEDs on the front face, everything else on the back, through-hole connectors accessible from the panel side — is part of the PCB Design Rules.