Dock Cell v0.1 — first real parametric part

The technical heart of the station: automated battery-swap + tank-refill cell, bench-rig configuration per requirements/dock-cell/*. Graduated from a space claim to 27-solid parametric geometry with 18 derived gates — verdict PASS.

Headline (machine-derived, build 3581841)

68 s

swap cycle, worst path

SWAP_CYCLE_TARGET ≤ 90 s

42 s

tank drain + refill (20 L)

TANK_REFILL_TARGET ≤ 45 s

327 kg

cell mass incl. 4 spare packs

zone claim ≤ 350 kg

150 A

battery contact rating

120 A × 1.25 margin

131.9 Wh/kg

14S 28 Ah pack energy density

plausibility band 100–200

2214 mm

prop-tip circle of landed E620P

the layout driver

±3 mm / ±2°

alignment absorbed by two-stage funnel

cups ±5 mm → pin chamfers

31 solids

model (body + drone reference)

FreeCAD verdict: PASSED

The geometry (CadQuery → Blender, build 3581841)

dock cell isometric render — Elevated platform + funnel cups under the (translucent) 2.2 m prop disc — the rotor plane is why the platform rises to 1 000 mm and all machinery stays ≥100 mm below it. Rack with 4 packs (yellow) right, fluid slide/pump/tote (blue) left, splash wall (orange) between.

dock cell top layout render — Layout plan (prop disc hidden) — chemical/electrical segregation: fluid side bottom, electrical side top, ≥250 mm separation + splash wall.

Rotate it live in the 3D viewer (Dock Cell button).

All 18 derived gates

check	value	bound
chem_elec_separation_mm	1030	>= 250 mm	PASS
splash_wall_between_zones	1.0	>= 1.0	PASS
funnel_capture_radius_mm	97.5	>= 50 mm	PASS
funnel_coarse_output_mm	5.0	<= 5 mm	PASS
fine_stage_absorb_mm	6	>= 3 mm	PASS
pack_keying_asymmetry_mm	2	> 0 mm	PASS
prop_clearance_mm	160	>= 100 mm	PASS
shuttle_reach_margin_mm	269.76	>= 0 mm	PASS
slide_reach_margin_mm	10	>= 0 mm	PASS
coupling_within_slide_z	1.0	>= 1.0	PASS
rack_stack_fits_envelope_mm	100	>= 0 mm	PASS
swap_cycle_worst_s	68.0	<= 90 s	PASS
refill_time_s	42.0	<= 45 s	PASS
contact_rating_a	150	>= 150.0 A	PASS
pack_wh_per_kg_min	131.85	>= 100 Wh/kg	PASS
pack_wh_per_kg_max	131.85	<= 200 Wh/kg	PASS
cell_mass_kg	327.0	<= 350 kg	PASS
max_part_overlap_mm3	0.0	<= 0 mm3	PASS

Container integration — measured, decided (ADR-0003)

A landed unfolded E620P does not fit inside the container. Prop circle 2214 mm vs dock-cell zone footprint 1600×1850 mm; in-container hover would leave ~52 mm per side to the walls — unflyable. Decision (ADR-0003): roof-deck landing. The drone lands on a recessed roof pad above the zone and never enters the container; machinery stays below with a vertical pack-lift stage (~74 s estimated cycle, re-gated in v0.2). Arm-fold + drone elevator was rejected — it modifies flight-critical arms (constraint 4) and blows the 90 s budget. Full argument: docs/design_decisions/0003-container-integration.md.

Every drone_interface value is an ESTIMATE pending measurement on real E620P hardware — re-confirm before fabrication drawings (parameters/dock_cell.yaml marks each one).

sources: cad/exports/dock_cell_report.json · parameters/dock_cell.yaml · requirements/dock-cell/*.md · falsifier + narrative: docs/verification_reports/dock-cell-v01.md