{
  "revision": "concept-r03-rs06-stock-brackets",
  "date_local": "2026-10-28",
  "timezone": "Asia/Seoul",
  "state": "rs06_r03_stock_brackets_and_hex_tooling_created_detail_design_pending",
  "accepted": {
    "scale": "Mini Cheetah class; exact dimensions and mass not fixed",
    "task": "stair locomotion; stair dimensions not fixed",
    "primary_leg_links": "3D printed",
    "shafts_bearings_transmission_hardware": "metal / purchased parts",
    "knee_motor_placement": "proximal to hip",
    "knee_transmission_candidates": [
      "belt",
      "rod_linkage"
    ],
    "design_source": "code-generated Fusion CAD reviewed interactively",
    "first_link_material_comparison": "PETG",
    "actuator_selection": {
      "model": "RobStride RS06",
      "confirmed_on": "2026-10-28",
      "user_instruction": "일단 RS06으로 설계해",
      "status": "provisional design basis; not purchase released"
    },
    "procurement": {
      "confirmed_on": "2026-10-28",
      "scope": "all non-3D-printed parts",
      "priority": "domestic Korean sellers first",
      "imported_brands_with_domestic_sellers": "allowed by user clarification",
      "domestic_stock_and_seller_overseas_order": "record separately",
      "overseas_direct_purchase": "exception only when suitable domestic procurement alternatives cannot meet requirements; record the reason and alternatives checked",
      "required_bom_fields": [
        "manufacturer",
        "model",
        "revision",
        "quantity",
        "domestic_seller",
        "domestic_product_url",
        "unit_price_krw",
        "vat_basis",
        "included_options",
        "stock_route",
        "lead_time_display",
        "checked_on",
        "compatibility_notes"
      ]
    },
    "assembly_standard": {
      "confirmed_on": "2026-10-28",
      "user_instruction": "브래킷 가능하면 기성품 쓰고, 공구도 통일해",
      "brackets": "prefer domestically sold stock brackets where compatible; preserve necessary custom RS06 carriers",
      "fasteners": "metric hex sockets; selected bolt bits 2.5, 3 and 4 mm with common 1/4-inch HEX holder",
      "scope": "modeled bolts and selected future motor screws; full assembly tooling and tightening torques not finalized"
    },
    "neutral_hip_stance": {
      "confirmed_on": "2026-10-28",
      "user_instruction": "힙 벌림 없애",
      "haa_outward_deg": 0,
      "scope": "remove outward angle from default standing pose, retain hip-abduction joint"
    }
  },
  "proposed_architecture": {
    "status": "initial implementation baseline; not finalized manufacturing design",
    "legs": [
      "FL",
      "FR",
      "RL",
      "RR"
    ],
    "actuated_joint_roles_per_leg": [
      "hip_abduction",
      "hip_flexion",
      "knee_flexion"
    ],
    "actuator_count": 12,
    "world_axes": {
      "X": "forward",
      "Y": "left",
      "Z": "up"
    },
    "cad_length_unit": "mm",
    "dynamics_length_unit": "m",
    "lower_link_candidate": "C, placed inboard in initial layout; preferred prototype only, not physically validated",
    "body_construction": "2020 aluminum profiles, 8 stock HBLFSN5-SET brackets, metal endplates and braces, PETG battery tray; supplier fits and full-robot stiffness unvalidated",
    "selected_actuator_configuration": "uniform_rs06_20261009",
    "actuator_count_basis": "12 identical RS06 actuators is the initial implementation assumption, not a separate user-specified quantity",
    "layout_baseline": {
      "status": "provisional dimensions for first RS06 assembly; final requirements remain open",
      "hip_to_knee_mm": 200,
      "knee_to_foot_center_mm": 195,
      "hip_flexion_and_knee_motor_arrangement": "proximal, coaxial and opposed; both motor housings fixed to hip-abduction carrier",
      "knee_transmission": "belt first; rod linkage remains a later comparison candidate",
      "knee_transmission_ratio": 1,
      "pulley_tooth_profile": "S5M",
      "pulley_teeth": [
        40,
        40
      ],
      "belt_pitch_length_mm": 600,
      "belt_width_mm": 25,
      "motor_to_joint_angle_mapping": "must include upper-link carrier motion and opposed motor-axis signs",
      "strength_status": "belt, hub, shaft, bearings, fasteners and full robot not yet validated",
      "cad_report": "rs06_r03/README.md",
      "geometry_parameters": "rs06_r03/parameters.json",
      "default_standing_pose": {
        "haa_outward_deg": 0,
        "hip_deg": 30,
        "knee_relative_deg": -60,
        "left_right_foot_center_spacing_mm": 220,
        "ground_contact": "foot centers Z=20 mm for nominal radius20 spheres",
        "status": "user-selected CAD pose; gait stability and full joint range unvalidated"
      }
    },
    "selected_motor_budget": {
      "catalog_unit_mass_g": 615,
      "catalog_12_motor_mass_kg": 7.38,
      "seller_unit_mass_g": 621,
      "seller_12_motor_mass_kg": 7.452,
      "domestic_unit_price_krw_vat_included": 448800,
      "domestic_12_motor_display_price_subtotal_krw": 5385600,
      "seller": "디바이스마트",
      "url": "https://www.devicemart.co.kr/goods/view?no=16042504",
      "checked_on": "2026-10-28",
      "procurement_status": "Korean seller overseas procurement; exact revision, quantity and delivery unconfirmed",
      "price_status": "display-price arithmetic only; not a final quotation; other components and shipping excluded"
    },
    "body_frame_r02": {
      "status": "historical r02 layout; superseded by body_frame_r03, not purchase or manufacturing released",
      "profile": "HFS5-2020 reference slot geometry",
      "longitudinal_members": {
        "count": 4,
        "length_mm": 340,
        "end_taps": "M5 both ends, nominal 15 mm"
      },
      "lower_crossmembers": {
        "count": 2,
        "length_mm": 230
      },
      "metal_endplate_thickness_mm": 5,
      "top_x_brace_thickness_mm": 2,
      "petg_tray_size_mm": [
        240,
        120,
        7.5
      ],
      "domestic_sourcing": "rs06_r02/frame_sources.md",
      "verification": "rs06_r02/cad/verification.json",
      "mass_status": "12.176 kg partial modeled subtotal; excludes battery, electronics, belts, pulleys, bearings, foot elastomer, wiring and unmodeled hardware",
      "printability": "13 individual PETG part bounds fit P2S; not sliced or physically printed"
    },
    "body_frame_r03": {
      "status": "user-requested CAD revision; not purchase or manufacturing released",
      "profile": "HFS5-2020 reference slot geometry",
      "longitudinal_members": {
        "count": 4,
        "length_mm": 340,
        "end_taps": "M5 both ends, nominal 15 mm"
      },
      "lower_crossmembers": {
        "count": 2,
        "length_mm": 230
      },
      "metal_endplate_thickness_mm": 5,
      "top_x_brace_thickness_mm": 2,
      "petg_tray_size_mm": [
        240,
        120,
        7.5
      ],
      "domestic_sourcing": "rs06_r03/research/stock_brackets.md",
      "verification": "rs06_r03/cad/verification.json",
      "mass_status": "12.291 kg partial modeled subtotal; excludes battery, electronics, belts, pulleys, bearings, foot elastomer, wiring and unmodeled hardware",
      "printability": "13 individual PETG part bounds fit P2S; not sliced or physically printed",
      "stock_brackets": {
        "model": "HBLFSN5-SET",
        "quantity": 8,
        "included_each": {
          "CBM5-10": 2,
          "HNTT5-5": 2
        },
        "supplier_cad_imported": false,
        "geometry_basis": "official 2D dimensions with undimensioned details approximated"
      },
      "Tnuts_total": 24,
      "standard_M5_washers": 12,
      "modeled_screws": 88,
      "hex_bits_mm": [
        2.5,
        3,
        4
      ],
      "tooling": "rs06_r03/research/tooling_standard.md",
      "assembly_inventory": "rs06_r03/assembly_bom.csv"
    }
  },
  "requirements_to_define": {
    "total_mass_kg": null,
    "payload_kg": null,
    "stair_rise_mm": null,
    "stair_tread_mm": null,
    "walking_speed_m_s": null,
    "operating_time_min": null,
    "parts_budget_and_currency": null,
    "body_envelope_mm": null,
    "hip_axis_positions_mm": null,
    "hip_to_knee_mm": null,
    "knee_to_foot_center_mm": null,
    "joint_limits_rad": null,
    "battery_pack_and_voltage": null,
    "computer_and_sensors": null
  },
  "existing_lower_link": {
    "source": "../v2_leg/link_candidates/README.md",
    "reference_knee_to_ball_mm": 195,
    "dimension_status": "reference CAD dimension, not a fixed V2 requirement",
    "interface_status": "bench flange; not compatible with a selected motor yet",
    "physical_tests_completed": 0
  },
  "screening_assumptions": {
    "status": "sensitivity cases only; not selected requirements or a dynamic simulation",
    "total_mass_kg": [
      8,
      10,
      12
    ],
    "supporting_feet": 2,
    "equal_vertical_load_sharing": true,
    "perpendicular_moment_arm_m": [
      0.1,
      0.15,
      0.195
    ],
    "vertical_load_multiplier": [
      1,
      2
    ],
    "gravity_m_s2": 9.81,
    "external_transmission_ratio": 1,
    "external_transmission_efficiency": 1,
    "notes": [
      "Total mass includes motors and all other robot components.",
      "The moment arm is perpendicular to the vertical foot force, not automatically the link length.",
      "Multiplier 2 is an illustrative force sensitivity, not an impact model or a safety factor.",
      "The 1:1 lossless external transmission is only a common screening baseline.",
      "Joint self-weight, inertia, horizontal force, nonuniform load sharing, thermal duty and speed are not modeled.",
      "Rated torque is manufacturer-condition data, not verified continuous torque in a printed mount."
    ]
  },
  "top_down_2026_11_01": {
    "status": "user requirements recorded as said; 'proposed' values come from a hand calculation and are not accepted",
    "user_requirements": {
      "design_order": "지금 너무 바텀업으로 접근한다. 설계를 할때는 탑다운으로 진행하는게 낫지 않아?",
      "scale": "미니치타 사이즈",
      "manufacturing": "최대한 3d printing",
      "procurement": "국내 부품 조달 가능",
      "stairs": "일반적인 계단이야. 근데 너무 집착하진 마",
      "printer": "P2s 프린터 걍 사고 따로 바꾸진 않았어"
    },
    "proposed": {
      "source": "top_down/README.md, top_down/budget.json",
      "note": "the 1.5 margin on the trot force, the pass line and the 17 kg target were fixed after the numbers were known",
      "total_mass_kg": 17.0,
      "hip_spacing_mm": 380,
      "foot_track_mm": 226,
      "hip_to_knee_mm": 200,
      "knee_to_foot_center_mm": 195,
      "motors": "RS06 x12",
      "knee_belt": "40T:52T (1.3:1)",
      "budget_kg": {
        "motors": 7.38,
        "legs": 6.32,
        "frame": 1.3,
        "electronics": 2.0
      },
      "non_motor_leg_allocation_g": {
        "carrier": 390.0,
        "drive": 600.0,
        "thigh": 350.0,
        "shin_foot": 145.0,
        "fasteners": 95.0
      },
      "design_loads": {
        "foot_N": 266.8,
        "knee_Nm": 38.0,
        "belt_N": 919.5,
        "side_N": 82.7,
        "haa_Nm": 20.0,
        "motor_cap_Nm": 29.3
      },
      "first_material_change": "PAHT-CF if the P2S prints it; PETG alone stops at about 17.4 kg with every lever working"
    },
    "still_open": [
      "walking_speed_m_s",
      "payload_kg",
      "operating_time_min",
      "parts_budget_and_currency",
      "battery_pack_and_voltage",
      "computer_and_sensors"
    ],
    "deciding_run": "stair simulation of a Mini-Cheetah-sized skeleton with Go2's official model as the control; models, environment, registered outcome meanings in top_down/sim/",
    "stairs_working_values": {
      "rise_mm": [
        160,
        180
      ],
      "tread_mm": [
        260,
        300
      ],
      "note": "working band for ordinary stairs, not measured and not a building-code value; the budget reference stays 160 x 280 mm because the knee demand changes only 34.7 to 38.3 N.m from a 100 to a 170 mm rise; the simulation sweeps rises of 120, 140, 160 and 180 mm on 280 mm treads"
    },
    "printer": {
      "model": "Bambu Lab P2S, stock",
      "nozzle": "0.4 mm hardened steel by retailer pages (Bambu pages could not be read), so the nozzle does not block PAHT-CF",
      "still_open": "no PAHT-CF spool in the lab, no Korean price found, no test print"
    }
  }
}