Machine Contact Large

Adom press-fit machine pin contact (Large) for the Adom modular electronics system. A machine contact (MC) is a receptacle pressed into a plated through-hole on a molecule or scaffold. It accepts a machine pin (MP) tail, a machine needle, or a bare wire, forming the solderless junction that ties molecules to the workcell control panel and to each other on the 32mm scaffold grid. This page carries the KiCad + Fusion 360 .lbr library, STEP, and an interactive 3D view.

What it is and where it goes

Large machine contacts populate the base scaffold (an 18x18 grid of large contacts at 32mm pitch) and large-class molecules. Their role depends on where they sit. On the base scaffold they are purely mechanical - that grid is not electrically connected, so the contacts serve only as the mechanical mounting interface that molecules and scaffolds seat into. Everywhere else (molecules, user scaffolds) they are electromechanical - carrying power and signal between stacked boards in addition to providing the mechanical interface. Large contacts are pressed directly into the board, and also press into the tops of large machine pins so that pins, needles, and wires can be inserted into a stacked assembly.

Rating and wiring

The rating is contact-limited (a large machine pin can carry more, so the 20.8 A figure is set by the contact) and is quoted at an 80% derating for margin. The mating wire is solid core (the enamel coating implies this, but it is called out explicitly).

Mounting: press-fit into a plated through-hole

The contact presses into a Ø2.62 mm plated through-hole ringed by a Ø4.40 mm copper annular pad. It is a solderless press-fit; solder-assist is available via the ring of 300um jet-paste solder balls on the annular ring (Adom's solder-ball-layer standard, shown in the 3D view above, which also animates the press-fit insertion). The hole must be plated and fabricated to the drill spec below.

Dimensions

Press-fit hole sizes are still under validation (Caleb is testing). The Ø2.62 mm drill here matches the current dimensions sheet and the shipped footprint; confirm against the latest dims sheet before committing a fabrication.

Files

• Fusion 360 library: MachineContactLarge.lbr (EAGLE/Fusion, round thru-hole pad + contact symbol)
• KiCad: MachineContactLarge.kicad_sym, MachineContactLarge.kicad_mod
• STEP: MachineContactLarge.step; web 3D: MachineContactLarge.glb
• Canonical adom-lbr JSON: MachineContactLarge.adom-lbr.json

Provenance and related

• Original KiCad source: adom-inc/adom-kicad-library (MachineContact + MachinePin).
• Dimensions originate in adom-inc/adom-tsci-library (lib/src/globals.ts), published as @tsci/adom-inc.library v1.2.1. That repository and the KiCad one above are private, so both links need org access.
• Public KiCad PCM feed, installable without a login: Adom KiCad Library, at https://wiki.adom.inc/adom/adom-kicad-library/pcm/repository.json
• Dimensions: Adom "Machine Pin Dimensions" sheet. Usage and ratings: "White Paper: Molecule Design" (v1.0, September 2025).
• Mating pins: adom/machinepinlargeshort, adom/machinepinlargestandard.
• Smaller sibling: adom/machinecontactmedium.

CAD provenance and independent review

Audit by Codex Astra (AI). Per-file provenance, sources and checks documents the current file hashes, source or generation inputs, modifications, verification limits and unknown origins. AI-created models are identified explicitly; a wiki upload is not manufacturer verification.

Unresolved original provenance: symbol, footprint, step, glb. See the record before treating these as source-verified assets.

Report a component problem with the filename/hash and evidence.

Optional MPN-marked model, preview and provenance

Displayed model and review status

The main 3D viewer uses machinecontactlarge-hero-mpn.glb, derived from the reviewed machinecontactlarge-mpn.glb. The exact MPN is AI-added identification artwork, not a factory marking. Marking inputs, fit and licensing and source provenance remain applicable.

The hero applies only a 180-degree Z display rotation; no geometry is scaled. Use the original-frame marked STEP/GLB downloads for board assemblies. The rendered package and readable mark were reviewed; that does not establish manufacturer-exact dimensions, polarity, or native-tool qualification. Binding and file hashes.

Footprint-aware inspection hero

The current hero adds separate nonphysical reference layers: teal dashed copper boundaries at 50% opacity, silkscreen at 30% opacity and actual symbol pin names (unique pad numbers when unnamed) at 50% opacity. Orbit underneath to compare physical terminals, copper and pin1 marks. Copper outlines are not soldermask/paste. Existing MPN, materials, animations and lights are preserved. These helpers are excluded from board-use STEP/GLB files. Geometry, mapping and source hashes; pin-map input. Physical body can occlude seating-plane artwork; inspect the underside or isolate it. Generated display-font contours are not native fab artwork.