{
  "version": "v0.35",
  "date": "2026-10-15",
  "status": "DESIGN_REVIEW_AND_INQUIRY",
  "manufacturing_release": false,
  "architecture": "Open-ground four-foot frame, fixed wheel axis and fixed specimen; spinning tread sliding",
  "coordinates": "mm; right-handed X longitudinal, Y axle/transverse, Z up; metal floor Z0",
  "foot_centres_x_mm": [-300, 300],
  "foot_centres_y_mm": [-375, 375],
  "foot_pad_side_mm": 150,
  "normal_footprint_mm": [750, 900],
  "frame_top_z_mm": 900,
  "frame_section_mm": [50, 50, 3],
  "wheel": {
    "type": "Pneumatic matched commercial tyre, tube and rim",
    "candidate": "Kenda K909 109090301B0",
    "nominal_diameter_mm": 200,
    "nominal_width_mm": 50,
    "catalogue_pressure_psi": 50,
    "catalogue_pressure_MPa": 0.3447378646584,
    "reservation_diameter_mm": 220,
    "reservation_width_mm": 70,
    "axis_z_mm": 180,
    "reference_surface_z_mm": 80,
    "true_inflated_dimensions_mm": null,
    "rim_bead_and_fasteners": null,
    "cold_speed_rating": null,
    "mass_kg_actual": null,
    "reservation_basis": "Design allowance only; not a measured K909 geometry"
  },
  "load_targets_N": [50, 100],
  "load_extension_N": 150,
  "tread_speed_aspiration_kmh": 60,
  "measurement_duration_s": [1, 5, 10],
  "motion": {"Y_manual_position_range_mm": [-150, 150], "Z_layout_offset_mm": [-40, 80], "Z_qualified_stroke_mm": null, "true_rolling_or_braking_slip_ratio": false},
  "wheel_carrier": {"cheek_inner_y_mm": [-76, 76], "cheek_thickness_mm": 10, "bridge_x_mm": [-125, 125], "bridge_bottom_top_z_mm": [335, 355], "shaft_nominal_diameter_mm": 20, "shaft_span_y_mm": [-140, 110], "bearing_centres_y_mm": [-65, 65], "bearing_size_reference_mm": [20, 47, 14], "bearing_exact_cold_part": null},
  "drive": {"motor_reference": "SENYDA SYD143-0310L30 unbraked", "power_W": 3100, "rated_speed_rpm": 3000, "rated_torque_Nm": 9.8, "catalogue_mass_kg": 10.5, "catalogue_rotor_inertia_kgm2": 0.000669, "motor_axis_xz_mm": [-160, 350], "motor_body_length_mm": 182, "motor_flange_mm": 143, "motor_shaft_mm": [28, 60], "motor_pulley_teeth": 30, "wheel_pulley_teeth": 45, "belt_pitch_mm": 5, "belt_width_reference_mm": 20, "ratio_motor_over_wheel": 1.5, "exact_cold_belt_and_drive": null},
  "sensors": {"main_force": "Six-axis candidate class; M3725A is comparison only", "selected_model": null, "interface_holes": null, "force_sample_target_Hz": 1000, "Z_thrust_feedback": true, "wheel_encoder_required": true, "compensated_cold_accuracy": null},
  "environment": {"working_targets_C": [-20, -30], "chamber_internal_mm": [6000, 4000, 2500], "floor_uniform_rating_kg_m2": 500, "floor_local_allowable_N": null, "approved_anchor": null, "closed_door_feedthrough": null},
  "material_candidates": {"frame": "S355NL or equivalent certified cold-tough steel; final material pending", "wheel_shaft": "42CrMo quenched/tempered candidate; cold toughness certificate pending", "measured_plate": "6082-T651 candidate; batch certificate pending"},
  "sources": ["../pneumatic_wheel_selection_v0_33/wheel_brief.json", "../system_audit_v0_34/system_calculations.json", "../common_support_v0_31/parameters.json"],
  "layout_decisions_proposed": ["New 200mm wheel carrier is a review layout, not a manufacturing release", "Bridge raised above wheel reserve; width widened, shaft span lengthened", "1.5 ratio selected for comparison, exact belt length and centre adjustment pending", "Open-ground route retained; removable closed specimen plate is comparison only"]
}