> Historical R3 button reference, retained for unchanged button mechanisms. Use the R3.1 root START_HERE and assembly for current files and light placement; R3 filenames and package paths below are historical.

# Switch estimation basis

The owner authorized a reasonable estimate-based prototype using online information. No LIDUOLE part-level mechanical drawing or measured sample data has been verified. The switches below are estimated reference geometry, not downloaded LIDUOLE OEM solids and not substitute procurement choices.

## Evidence

- Owner-selected LIDUOLE sizes: PTT 6 x 6 x 6; volume x2 6 x 6 x 5; front 12 x 12 x 4.3 mm, four-pin momentary variants. The third dimension is treated provisionally as released overall height above the body mounting plane, excluding leads.
- A matching LIDUOLE assortment listing contains these sizes. The exact purchased ASIN has not been confirmed: https://www.amazon.com/dp/B0H6PPJYHX . The listing is not a travel/force/tolerance drawing.
- E-Switch TL1105 is an analogous 6 mm family. Its primary datasheet gives typical travel 0.25 mm and dimensioned body/lead diagrams. This supports the small-switch travel estimate and the general reference layout, not equivalence to LIDUOLE: https://configured-product-images.s3.amazonaws.com/Datasheets/TL1105.pdf . Research copy in the local workspace (the portable package links to the source): `reference/ESwitch_TL1105_ANALOG_NOT_LIDUOLE.pdf`.
- E-Switch TL1100 is an analogous 12 mm family. Its primary datasheet gives typical travel 0.30 mm and includes a 4.3 mm-height option and lead diagrams. It is used only as a mechanical analogy: https://configured-product-images.s3.amazonaws.com/Datasheets/TL1100.pdf . Research copy in the local workspace (the portable package links to the source): `reference/ESwitch_TL1100_ANALOG_NOT_LIDUOLE.pdf`.

## Explicit modeling assumptions

| Reference feature | Small switches | Front switch |
|---|---:|---:|
| Housing footprint | 6 x 6 | 12 x 12 |
| Fixed housing depth | 3.6 | 3.5 |
| Plunger diameter | 3.5 | 7.1 |
| Released overall height, excluding leads | 6 PTT / 5 volume | 4.3 |
| Lead projection behind mounting plane | 3.5 | 3.5 |
| Simplified lead section | 0.9 x 0.3 | 1.0 x 0.3 |
| Lead positions in footprint plane | +/-3.25 and +/-2.25 | +/-6.25 and +/-2.5 |

These values combine owner nominal dimensions, same-footprint manufacturer examples and deliberately simplified reference geometry. Not every listed value is directly stated in a LIDUOLE or E-Switch drawing. Plungers, housing corners and terminals are simplified rather than detailed stamped/formed supplier geometry. There is no modeled internal dome, contact mechanics, spring curve or guaranteed maximum travel.

Separate hidden `KEEP_OUT` bodies reserve local terminal/solder space. They are clearance gauges, not physical parts. They cover immediate joints, not the complete final cable harness or manufacturing access sequence. Actual insulated wire and solder geometry must fit these channels or trigger a local revision.

The default external key travel is a design setting, not a switch specification. Thin contacts, bearing shims and carrier stop shims make this setting tunable. Never interpret a nominal CAD clearance as proof that all assortment variants share the same tolerances or operating force.

## Authoring and provenance

The complete R2 Fusion archive was copied before editing. All device and tuning geometry was authored with Autodesk Fusion's native BRep and sketch APIs through its Python console. Adam MCP was not used. Independent OpenCascade checks inspect exported geometry only. The saved F3D is the editable deliverable; scripts document the incremental authoring steps, not a one-command parametric product generator. Their dimensions are not automatically linked to a user-parameter table.

R2's missing-U6 envelope remains nominal; the supplied PCB model, antenna identity and no-GNSS prototype direction are retained. Unresolved R2 physical/electrical/RF checks are not converted into passes by this button revision.