{ "spec_version": "0.7.0-draft.5", "slug": "koch-arm", "as_of": "2026-10-04", "region": "US", "currency": "USD", "note": "Dated observations, not checkout quotes. Confirmed broken or unavailable listings remain in history but do not count. No referral links. Shipping and tax are separate.", "configurations": [ { "configuration_id": "koch-pair-extension", "label": "Koch follower + leader, elbow-to-wrist extension", "first_task": "Leader-follower teleoperation with the repository scripts", "upstream_bom_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "upstream_revision": "0602b0c1e6a67d8f6ab96f81d1378639018d98af", "bom_coverage": { "status": "partial", "source_ids": [ "S001" ], "notes": "README tables reconciled line by line; servo and frame packages include their bolts per ROBOTIS package contents. Not complete: screws for mounting the driver board and voltage reducer to the base, and solder, are not listed." }, "labor_hours": { "value": null, "status": "unknown" }, "ownership_scenarios": [ { "scenario_id": "owns-computer-and-printer", "owned_requirements": [ { "requirement_id": "host-computer", "quantity": 1, "basis": "documented_assumption", "note": "Common case: reader already has a suitable computer." }, { "requirement_id": "printer", "quantity": 1, "basis": "documented_assumption", "note": "Common case: reader already has a 3D printer." } ] } ], "shipping_estimates": [], "lines": [ { "line_id": "xl430", "part_id": "dynamixel-xl430-w250-t", "quantity": 2, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "xl330-m288", "part_id": "dynamixel-xl330-m288-t", "quantity": 4, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "xl330-idlers-f", "part_id": "robotis-fpx330-h101-idler", "quantity": 3, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Three idlers for the elbow-to-wrist extension geometry." }, { "line_id": "xl430-idler", "part_id": "robotis-hn11-i101-idler", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "One set as listed upstream." }, { "line_id": "driver-board-f", "part_id": "serial-bus-servo-driver-board", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Same listing as upstream (a.co/d/7C3RUYU -> B0CTMM4LWK)." }, { "line_id": "voltage-reducer", "part_id": "lm2596-buck-converter", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "One of the six-pack per follower." }, { "line_id": "psu-12v", "part_id": "psu-12v-5a-barrel", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "wires", "part_id": "dupont-jumper-wire-kit", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "clamp-f", "part_id": "small-bar-clamp", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Upstream links a BESSEY CM30 3\" C-clamp (USD 6); its listing showed no price on 2026-10-04, so generic clamp offers are used." }, { "line_id": "usb-cable-f", "part_id": "usb-a-to-usb-c-cable", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "README: a USB-C cable is necessary to connect the driver board." }, { "line_id": "soldering", "part_id": "soldering-iron", "quantity": 1, "layer": "tools", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Wires are soldered onto the voltage reducer." }, { "line_id": "xl330-m077", "part_id": "dynamixel-xl330-m077-t", "quantity": 6, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "xl330-frames", "part_id": "robotis-fpx330-s101-frame", "quantity": 4, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "One set of four, as listed upstream." }, { "line_id": "xl330-idlers-l", "part_id": "robotis-fpx330-h101-idler", "quantity": 3, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Three idlers for the extension geometry." }, { "line_id": "driver-board-l", "part_id": "serial-bus-servo-driver-board", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "psu-5v", "part_id": "psu-5v-2a-barrel", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "clamp-l", "part_id": "small-bar-clamp", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "usb-cable-l", "part_id": "usb-a-to-usb-c-cable", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "host-computer", "part_id": "host-computer-lerobot", "quantity": 1, "layer": "host_compute", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Computer running the Dynamixel SDK control scripts." }, { "line_id": "printer", "part_id": "fdm-3d-printer", "quantity": 1, "layer": "tools", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Required for the self-print route." } ], "printed": { "groups": [ { "requirement_id": "follower-frame", "required": true, "source_ids": [ "S001", "S004" ], "route": "self_print", "material_part_id": "pla-filament", "mass_low_g": 86.3, "mass_high_g": 100.8, "method": "Slicer: PrusaSlicer-2.9.6 based on Slic3r (with GUI support); each file sliced separately (retained source evidence): low = 2 perimeters and 15% infill, high = PrusaSlicer defaults (3 perimeters, 20% infill).", "assumptions": "Upstream states only that the moving gripper part needs supports; material, nozzle, layer height and infill are not stated, so PLA, 0.4 mm nozzle and 0.2 mm layers are assumed and infill/perimeters span a stated range. Elbow-to-wrist extension geometry; both elbow_to_wrist files are included (the short piece may be unused, about 5 g). arm.stl / leader_arm.stl are assembly exports and are not printed. No skirt or brim; one successful print, no reprint allowance.", "estimate_complete": true, "parts": [ { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/base.stl", "sha256": "c9d8ea55fabd991f90f027cde7b483db45add2e84a97e881fd4c3ab5885b7ede", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/elbow_to_wrist.stl", "sha256": "151a20045b6930e547150437c36fb8b4c502528a5b1de28b01a51611a39db1a4", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/elbow_to_wrist_extension.stl", "sha256": "ad9b96dabfa31cc6b19af3878e8ac3a839e72e0982d9708b49f10a581ca67fe2", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/gripper_moving_part.stl", "sha256": "a777302975d25eb74a58c874e589354d61c68fdbea55bdffec29d6cb94572308", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/gripper_static_part.stl", "sha256": "bcdebd1a97ec9f4273e17d01a608d8bc23f609642b9b298aa0e0f90050218229", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/shoulder_rotation.stl", "sha256": "ae810fc00b5ae9ec110bb54ab2107d1dbd3a0cb03eca83c5d0bace603d0f4a9c", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/shoulder_to_elbow.stl", "sha256": "4137f9d21af1faeee36697385254040a548bdcef0133830dd1fdc0f22b0897e2", "quantity": 1, "included": true, "role": "kit" } ] }, { "requirement_id": "leader-frame", "required": true, "source_ids": [ "S001", "S004" ], "route": "self_print", "material_part_id": "pla-filament", "mass_low_g": 63.5, "mass_high_g": 76.9, "method": "Slicer: PrusaSlicer-2.9.6 based on Slic3r (with GUI support); each file sliced separately (retained source evidence): low = 2 perimeters and 15% infill, high = PrusaSlicer defaults (3 perimeters, 20% infill).", "assumptions": "Upstream states only that the moving gripper part needs supports; material, nozzle, layer height and infill are not stated, so PLA, 0.4 mm nozzle and 0.2 mm layers are assumed and infill/perimeters span a stated range. Elbow-to-wrist extension geometry; both elbow_to_wrist files are included (the short piece may be unused, about 5 g). arm.stl / leader_arm.stl are assembly exports and are not printed. No skirt or brim; one successful print, no reprint allowance.", "estimate_complete": true, "parts": [ { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/leader/stl/base.stl", "sha256": "4c0c1867020a2692fdad4340b3168fb9a741750338c75fa59367e5a8b601c02f", "quantity": 1, "included": true, "role": "leader_only" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/leader/stl/elbow_to_wrist.stl", "sha256": "151a20045b6930e547150437c36fb8b4c502528a5b1de28b01a51611a39db1a4", "quantity": 1, "included": true, "role": "leader_only" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/leader/stl/elbow_to_wrist_extension.stl", "sha256": "ad9b96dabfa31cc6b19af3878e8ac3a839e72e0982d9708b49f10a581ca67fe2", "quantity": 1, "included": true, "role": "leader_only" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/leader/stl/gripper_handle.stl", "sha256": "edc5fb3d52795de890d13403834c5b3b80da71e01645ea4688ab0ae7f93a1bfc", "quantity": 1, "included": true, "role": "leader_only" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/leader/stl/gripper_trigger.stl", "sha256": "0244f26f536d127d05d897a25a80cf4adee6f2faf7072223fa1be2f444916e94", "quantity": 1, "included": true, "role": "leader_only" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/leader/stl/shoulder_to_elbow.stl", "sha256": "50076340edf9c1602cfa946266fac894609c143fbabe9bdc1c24ec7fa7e4581d", "quantity": 1, "included": true, "role": "leader_only" } ] } ] } }, { "configuration_id": "koch-follower-extension", "label": "Koch follower only, elbow-to-wrist extension", "first_task": "Follower arm controlled from a computer with the Dynamixel SDK", "upstream_bom_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "upstream_revision": "0602b0c1e6a67d8f6ab96f81d1378639018d98af", "bom_coverage": { "status": "partial", "source_ids": [ "S001" ], "notes": "README tables reconciled line by line; servo and frame packages include their bolts per ROBOTIS package contents. Not complete: screws for mounting the driver board and voltage reducer to the base, and solder, are not listed." }, "labor_hours": { "value": null, "status": "unknown" }, "ownership_scenarios": [ { "scenario_id": "owns-computer-and-printer", "owned_requirements": [ { "requirement_id": "host-computer", "quantity": 1, "basis": "documented_assumption", "note": "Common case: reader already has a suitable computer." }, { "requirement_id": "printer", "quantity": 1, "basis": "documented_assumption", "note": "Common case: reader already has a 3D printer." } ] } ], "shipping_estimates": [], "lines": [ { "line_id": "xl430", "part_id": "dynamixel-xl430-w250-t", "quantity": 2, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "xl330-m288", "part_id": "dynamixel-xl330-m288-t", "quantity": 4, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "xl330-idlers-f", "part_id": "robotis-fpx330-h101-idler", "quantity": 3, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Three idlers for the elbow-to-wrist extension geometry." }, { "line_id": "xl430-idler", "part_id": "robotis-hn11-i101-idler", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "One set as listed upstream." }, { "line_id": "driver-board-f", "part_id": "serial-bus-servo-driver-board", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Same listing as upstream (a.co/d/7C3RUYU -> B0CTMM4LWK)." }, { "line_id": "voltage-reducer", "part_id": "lm2596-buck-converter", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "One of the six-pack per follower." }, { "line_id": "psu-12v", "part_id": "psu-12v-5a-barrel", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "wires", "part_id": "dupont-jumper-wire-kit", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "" }, { "line_id": "clamp-f", "part_id": "small-bar-clamp", "quantity": 1, "layer": "purchased_parts", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Upstream links a BESSEY CM30 3\" C-clamp (USD 6); its listing showed no price on 2026-10-04, so generic clamp offers are used." }, { "line_id": "usb-cable-f", "part_id": "usb-a-to-usb-c-cable", "quantity": 1, "layer": "power_and_cabling", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "README: a USB-C cable is necessary to connect the driver board." }, { "line_id": "soldering", "part_id": "soldering-iron", "quantity": 1, "layer": "tools", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Wires are soldered onto the voltage reducer." }, { "line_id": "host-computer", "part_id": "host-computer-lerobot", "quantity": 1, "layer": "host_compute", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Computer running the Dynamixel SDK control scripts." }, { "line_id": "printer", "part_id": "fdm-3d-printer", "quantity": 1, "layer": "tools", "required": true, "source_ids": [ "S001" ], "substitutes": [], "notes": "Required for the self-print route." } ], "printed": { "groups": [ { "requirement_id": "follower-frame", "required": true, "source_ids": [ "S001", "S004" ], "route": "self_print", "material_part_id": "pla-filament", "mass_low_g": 86.3, "mass_high_g": 100.8, "method": "Slicer: PrusaSlicer-2.9.6 based on Slic3r (with GUI support); each file sliced separately (retained source evidence): low = 2 perimeters and 15% infill, high = PrusaSlicer defaults (3 perimeters, 20% infill).", "assumptions": "Upstream states only that the moving gripper part needs supports; material, nozzle, layer height and infill are not stated, so PLA, 0.4 mm nozzle and 0.2 mm layers are assumed and infill/perimeters span a stated range. Elbow-to-wrist extension geometry; both elbow_to_wrist files are included (the short piece may be unused, about 5 g). arm.stl / leader_arm.stl are assembly exports and are not printed. No skirt or brim; one successful print, no reprint allowance.", "estimate_complete": true, "parts": [ { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/base.stl", "sha256": "c9d8ea55fabd991f90f027cde7b483db45add2e84a97e881fd4c3ab5885b7ede", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/elbow_to_wrist.stl", "sha256": "151a20045b6930e547150437c36fb8b4c502528a5b1de28b01a51611a39db1a4", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/elbow_to_wrist_extension.stl", "sha256": "ad9b96dabfa31cc6b19af3878e8ac3a839e72e0982d9708b49f10a581ca67fe2", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/gripper_moving_part.stl", "sha256": "a777302975d25eb74a58c874e589354d61c68fdbea55bdffec29d6cb94572308", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/gripper_static_part.stl", "sha256": "bcdebd1a97ec9f4273e17d01a608d8bc23f609642b9b298aa0e0f90050218229", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/archive/0602b0c1e6a67d8f6ab96f81d1378639018d98af.tar.gz", "path": "hardware/follower/stl/shoulder_rotation.stl", "sha256": "ae810fc00b5ae9ec110bb54ab2107d1dbd3a0cb03eca83c5d0bace603d0f4a9c", "quantity": 1, "included": true, "role": "kit" }, { "archive_url": 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"price_observed_at": "2026-10-04" }, { "group": "part:psu-12v-5a-barrel", "part_id": "psu-12v-5a-barrel", "offer_id": "amazon-b0byvk73bp", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 11.99, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:robotis-fpx330-h101-idler", "part_id": "robotis-fpx330-h101-idler", "offer_id": "robotis-fpx330-h101-4pcs-set", "observation_id": "robotis-2026-10-04", "packs": 1, "expenditure": 11.27, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:robotis-hn11-i101-idler", "part_id": "robotis-hn11-i101-idler", "offer_id": "robotis-hn11-i101-set", "observation_id": "robotis-2026-10-04", "packs": 1, "expenditure": 8.05, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:serial-bus-servo-driver-board", "part_id": "serial-bus-servo-driver-board", "offer_id": "amazon-b0ctmm4lwk", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 12.47, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:small-bar-clamp", "part_id": "small-bar-clamp", "offer_id": "amazon-b0djnxf8wh", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 9.99, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:usb-a-to-usb-c-cable", "part_id": "usb-a-to-usb-c-cable", "offer_id": "amazon-b0b8nwllw2", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 7.19, "check_method": "manual", "price_observed_at": "2026-10-04" } ] }, "as_of_date": "2026-10-04", "computed_at": "2026-10-04", "tool_version": "0.7.0-draft.5", "tool_hash": "b3a901ff5bbade76fe67cecf535fd822a7fce97a6b33b761ac6a8bfc1edffc23" }, { "configuration_id": "koch-follower-extension", "region": "US", "currency": "USD", "scenario_id": "owns-computer-and-printer", "layers": { "purchased_parts": { "low": 204.7, "high": 206.74, "required_groups": 6, "priced_groups": 6, "unpriced": [], "oldest_price_date": "2026-10-04", 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"priced_groups": 1, "unpriced": [ "soldering" ], "oldest_price_date": null, "newest_price_date": null }, "shipping_tax": { "low": 0, "high": 0, "required_groups": 1, "priced_groups": 0, "unpriced": [ "shipping_tax" ], "oldest_price_date": null, "newest_price_date": null } }, "labor_hours": { "value": null, "status": "unknown" }, "bom_coverage": "partial", "pricing_coverage": { "required_groups": 12, "priced_groups": 10, "ratio": 0.8333, "unpriced": [ "soldering", "voltage-reducer" ] }, "setup_readiness": "incomplete", "parts_total": { "low": 245.85, "high": null, "complete": false, "gaps": [ "voltage-reducer" ] }, "required_total": { "low": 245.85, "high": null, "complete": false, "gaps": [ "shipping_tax", "soldering", "voltage-reducer" ] }, "price_dates": { "oldest": "2026-10-04", "newest": "2026-10-04", "upstream_reported_groups": [] }, "selected_observations": { "low": [ { "group": "material:pla-filament", "part_id": "pla-filament", "offer_id": "amazon-b0cs2zsz6f", "observation_id": 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"observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 11.99, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:robotis-fpx330-h101-idler", "part_id": "robotis-fpx330-h101-idler", "offer_id": "robotis-fpx330-h101-4pcs-set", "observation_id": "robotis-2026-10-04", "packs": 1, "expenditure": 11.27, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:robotis-hn11-i101-idler", "part_id": "robotis-hn11-i101-idler", "offer_id": "robotis-hn11-i101-set", "observation_id": "robotis-2026-10-04", "packs": 1, "expenditure": 8.05, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:serial-bus-servo-driver-board", "part_id": "serial-bus-servo-driver-board", "offer_id": "amazon-b0ctmm4lwk", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 12.47, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:small-bar-clamp", "part_id": "small-bar-clamp", "offer_id": "amazon-b092l925j4", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 7.95, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:usb-a-to-usb-c-cable", "part_id": "usb-a-to-usb-c-cable", "offer_id": "amazon-b0b8nwllw2", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 7.19, "check_method": "manual", "price_observed_at": "2026-10-04" } ], "high": [ { "group": "material:pla-filament", "part_id": "pla-filament", "offer_id": "amazon-b0cs2zsz6f", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 14.99, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:dupont-jumper-wire-kit", "part_id": "dupont-jumper-wire-kit", "offer_id": "amazon-b01ev70c78", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 6.98, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:dynamixel-xl330-m288-t", "part_id": "dynamixel-xl330-m288-t", "offer_id": "robotis-dynamixel-xl330-m288-t", "observation_id": "robotis-2026-10-04", "packs": 4, "expenditure": 109.96, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:dynamixel-xl430-w250-t", "part_id": "dynamixel-xl430-w250-t", "offer_id": "robotis-dynamixel-xl430-w250-t", "observation_id": "robotis-2026-10-04", "packs": 2, "expenditure": 55, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:psu-12v-5a-barrel", "part_id": "psu-12v-5a-barrel", "offer_id": "amazon-b0byvk73bp", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 11.99, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:robotis-fpx330-h101-idler", "part_id": "robotis-fpx330-h101-idler", "offer_id": "robotis-fpx330-h101-4pcs-set", "observation_id": "robotis-2026-10-04", "packs": 1, "expenditure": 11.27, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:robotis-hn11-i101-idler", "part_id": "robotis-hn11-i101-idler", "offer_id": "robotis-hn11-i101-set", "observation_id": "robotis-2026-10-04", "packs": 1, "expenditure": 8.05, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:serial-bus-servo-driver-board", "part_id": "serial-bus-servo-driver-board", "offer_id": "amazon-b0ctmm4lwk", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 12.47, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:small-bar-clamp", "part_id": "small-bar-clamp", "offer_id": "amazon-b0djnxf8wh", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 9.99, "check_method": "manual", "price_observed_at": "2026-10-04" }, { "group": "part:usb-a-to-usb-c-cable", "part_id": "usb-a-to-usb-c-cable", "offer_id": "amazon-b0b8nwllw2", "observation_id": "amazon-2026-10-04", "packs": 1, "expenditure": 7.19, "check_method": "manual", "price_observed_at": "2026-10-04" } ] }, "as_of_date": "2026-10-04", "computed_at": "2026-10-04", "tool_version": "0.7.0-draft.5", "tool_hash": "b3a901ff5bbade76fe67cecf535fd822a7fce97a6b33b761ac6a8bfc1edffc23" } ], "parts": { "dupont-jumper-wire-kit": { "name": "Dupont jumper wire kit (M-F, M-M, F-F)", "unit": "each", "spec_summary": "Assorted 20 cm Dupont jumper wires, 120 pieces.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "ELEGOO 120pcs Multicolored Dupont Wire M-F, M-M, F-F for Breadboard Jumper", "url": "https://www.amazon.com/dp/B01EV70C78", "publisher": "Amazon.com", "locator": "Buy box captured for listing \"dupont-jumper-wires-elegoo\"", "finding": "Current price, availability and seller as displayed.", "accessed_at": "2026-10-04", "attribution_note": "Captured in the built-in browser; scripted fetches received CAPTCHA pages, which were not bypassed." } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "Amazon listing linked from Koch README", "url": "https://www.amazon.com/dp/B01EV70C78", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 7, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "amazon-b01ev70c78", "supplier": "ELEGOO Official US", "url": "https://www.amazon.com/dp/B01EV70C78", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 6.98, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Buy box read on 2026-10-04; seller: ELEGOO Official US; availability: In Stock. Upstream short link https://a.co/d/hQfk2cb." } ] } ] }, "dynamixel-xl330-m077-t": { "name": "DYNAMIXEL XL330-M077-T", "unit": "each", "spec_summary": "ROBOTIS DYNAMIXEL XL330-M077-T TTL servo; package includes cable and horn/frame bolts.", "manufacturer": "ROBOTIS", "mpn": "XL330-M077-T", "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "DYNAMIXEL XL330-M077-T", "url": "https://www.robotis.us/dynamixel-xl330-m077-t/", "publisher": "ROBOTIS AMERICA", "locator": "Product structured data (schema.org Offer) and package contents", "finding": "Price, availability and package contents in the product page.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "ROBOTIS America (linked from Koch README)", "url": "https://www.robotis.us/dynamixel-xl330-m077-t/", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 24, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "robotis-dynamixel-xl330-m077-t", "supplier": "ROBOTIS America", "url": "https://www.robotis.us/dynamixel-xl330-m077-t/", "region": "US", "observations": [ { "observation_id": "robotis-2026-10-04", "currency": "USD", "pack_price": 27.49, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "ROBOTIS America US store; shipping calculated at checkout, not established.", "notes": "schema.org Offer price 27.49 USD, availability http://schema.org/InStock." } ] } ] }, "dynamixel-xl330-m288-t": { "name": "DYNAMIXEL XL330-M288-T", "unit": "each", "spec_summary": "ROBOTIS DYNAMIXEL XL330-M288-T TTL servo; package includes cable and horn/frame bolts.", "manufacturer": "ROBOTIS", "mpn": "XL330-M288-T", "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "DYNAMIXEL XL330-M288-T", "url": "https://www.robotis.us/dynamixel-xl330-m288-t/", "publisher": "ROBOTIS AMERICA", "locator": "Product structured data (schema.org Offer) and package contents", "finding": "Price, availability and package contents in the product page.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "ROBOTIS America (linked from Koch README)", "url": "https://www.robotis.us/dynamixel-xl330-m288-t/", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 24, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "robotis-dynamixel-xl330-m288-t", "supplier": "ROBOTIS America", "url": "https://www.robotis.us/dynamixel-xl330-m288-t/", "region": "US", "observations": [ { "observation_id": "robotis-2026-10-04", "currency": "USD", "pack_price": 27.49, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "ROBOTIS America US store; shipping calculated at checkout, not established.", "notes": "schema.org Offer price 27.49 USD, availability http://schema.org/InStock." } ] } ] }, "dynamixel-xl430-w250-t": { "name": "DYNAMIXEL XL430-W250-T", "unit": "each", "spec_summary": "ROBOTIS DYNAMIXEL XL430-W250-T TTL servo; package includes cable, horn/frame bolts and spacers.", "manufacturer": "ROBOTIS", "mpn": "902-0135-000", "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "DYNAMIXEL XL430-W250-T", "url": "https://www.robotis.us/dynamixel-xl430-w250-t/", "publisher": "ROBOTIS AMERICA", "locator": "Product structured data (schema.org Offer) and package contents", "finding": "Price, availability and package contents in the product page.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "ROBOTIS America (linked from Koch README)", "url": "https://www.robotis.us/dynamixel-xl430-w250-t/", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 50, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "robotis-dynamixel-xl430-w250-t", "supplier": "ROBOTIS America", "url": "https://www.robotis.us/dynamixel-xl430-w250-t/", "region": "US", "observations": [ { "observation_id": "robotis-2026-10-04", "currency": "USD", "pack_price": 27.5, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "ROBOTIS America US store; shipping calculated at checkout, not established.", "notes": "schema.org Offer price 27.50 USD, availability http://schema.org/InStock." } ] } ] }, "fdm-3d-printer": { "name": "FDM 3D printer (220 x 220 mm bed or larger)", "unit": "each", "spec_summary": "FDM printer with at least a 220 x 220 mm bed (upstream also lists 205 x 250 mm beds).", "manufacturer": null, "mpn": null, "identity_sources": [ "S001" ], "substitutes": [], "notes": "Required only for the self-print route; reference option not yet chosen.", "sources": [ { "id": "S001", "type": "upstream", "title": "SO-ARM100 README bill of materials", "url": "https://github.com/TheRobotStudio/SO-ARM100/blob/5f6d2b876a53a4872e405b991dd925556c9e38a4/README.md", "publisher": "TheRobotStudio", "locator": "Sourcing Parts: Parts for One Follower Arm; Parts For Two Arms", "finding": "Lists part names, amounts and US unit costs with purchase links.", "accessed_at": "2026-10-04" } ], "offers": [] }, "host-computer-lerobot": { "name": "Host computer able to run LeRobot", "unit": "each", "spec_summary": "Computer with USB that runs the LeRobot environment; no specific model selected.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001" ], "substitutes": [], "notes": "Reference option not yet chosen; required unless already owned.", "sources": [ { "id": "S001", "type": "upstream", "title": "SO-ARM100 README bill of materials", "url": "https://github.com/TheRobotStudio/SO-ARM100/blob/5f6d2b876a53a4872e405b991dd925556c9e38a4/README.md", "publisher": "TheRobotStudio", "locator": "Sourcing Parts: Parts for One Follower Arm; Parts For Two Arms", "finding": "Lists part names, amounts and US unit costs with purchase links.", "accessed_at": "2026-10-04" } ], "offers": [] }, "lm2596-buck-converter": { "name": "LM2596 adjustable buck converter module", "unit": "each", "spec_summary": "LM2596S DC-DC step-down module, 3 A, adjustable output; sold as a 6-pack.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "Koch uses one per follower to reduce 12 V to 5 V for the XL330 chain.", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "Queta 6 Pieces LM2596s DC to DC Buck Converter Step Down Voltage Regulator Power Module 3.2-40V to 1.25-35V 3A High Efficiency DC Voltage Stabilizer Volt Transformer LM2596 DC-DC Buck Converter", "url": "https://www.amazon.com/dp/B08G4GYNL6", "publisher": "Amazon.com", "locator": "Buy box captured for listing \"voltage-reducer-lm2596-6pack\"", "finding": "Current price, availability and seller as displayed.", "accessed_at": "2026-10-04", "attribution_note": "Captured in the built-in browser; scripted fetches received CAPTCHA pages, which were not bypassed." } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "Amazon listing linked from Koch README", "url": "https://www.amazon.com/dp/B08G4GYNL6", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 10, "pack_qty": 6, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "amazon-b08g4gynl6", "supplier": "Amazon.com marketplace (no featured offer)", "url": "https://www.amazon.com/dp/B08G4GYNL6", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": null, "pack_qty": 6, "moq_packs": 1, "stock": "out_of_stock", "source_checked_at": "2026-10-04", "price_observed_at": null, "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Buy box read on 2026-10-04; seller: None; availability: Currently unavailable. We don't know when or if this item will be back in stock.. Upstream short link https://a.co/d/cy02ADW." } ] } ] }, "pla-filament": { "name": "PLA filament, 1.75 mm", "unit": "g", "spec_summary": "Generic PLA filament, 1.75 mm; any colour.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001" ], "substitutes": [], "notes": "Unit is grams; a 1 kg spool is a pack of 1000.", "sources": [ { "id": "S001", "type": "vendor", "title": "eSUN PLA Basic Filament 1.75mm 3D Printer Filament 1KG Silver", "url": "https://www.amazon.com/dp/B0CS2ZSZ6F", "publisher": "Amazon.com", "locator": "Buy box captured for listing \"filament-esun-pla-basic-1kg\"", "finding": "Current price, availability and seller as displayed.", "accessed_at": "2026-10-04", "attribution_note": "Captured in the built-in browser; scripted fetches received CAPTCHA pages, which were not bypassed." } ], "offers": [ { "offer_id": "amazon-b0cs2zsz6f", "supplier": "eSUN official Store", "url": "https://www.amazon.com/dp/B0CS2ZSZ6F", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 14.99, "pack_qty": 1000, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S001" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Buy box read on 2026-10-04; seller: eSUN official Store; variants: Silver, 1KG." } ] } ] }, "psu-12v-5a-barrel": { "name": "12 V 5 A power supply, barrel plug", "unit": "each", "spec_summary": "12 V DC, 5 A wall adapter with barrel plug.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "Facmogu 12V 5A Power Supply Adapter, AC 100-240V to DC 12V Converter", "url": "https://www.amazon.com/dp/B0BYVK73BP", "publisher": "Amazon.com", "locator": "Buy box captured for listing \"psu-12v-5a-facmogu\"", "finding": "Current price, availability and seller as displayed.", "accessed_at": "2026-10-04", "attribution_note": "Captured in the built-in browser; scripted fetches received CAPTCHA pages, which were not bypassed." } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "Amazon listing linked from Koch README", "url": "https://www.amazon.com/dp/B0BYVK73BP", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 12, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "amazon-b0byvk73bp", "supplier": "Mo-gu", "url": "https://www.amazon.com/dp/B0BYVK73BP", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 11.99, "pack_qty": 1, "moq_packs": 1, "stock": "low", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Buy box read on 2026-10-04; seller: Mo-gu; availability: Only 14 left in stock - order soon.. Upstream short link https://a.co/d/40o8uMN." } ] } ] }, "psu-5v-2a-barrel": { "name": "5 V 2 A power supply, barrel plug", "unit": "each", "spec_summary": "5 V DC, 2 A wall adapter with 5.5 mm barrel plug.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "5V 2A Power Adapter Supply 10W DC 5V 2A 1.5A 1A Wall Plug Power Cord", "url": "https://www.amazon.com/dp/B0BZS779MC", "publisher": "Amazon.com", "locator": "Buy box captured for listing \"psu-5v-2a\"", "finding": "Current price, availability and seller as displayed.", "accessed_at": "2026-10-04", "attribution_note": "Captured in the built-in browser; scripted fetches received CAPTCHA pages, which were not bypassed." } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "Amazon listing linked from Koch README", "url": "https://www.amazon.com/dp/B0BZS779MC", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 6, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "amazon-b0bzs779mc", "supplier": "GUOHONGZHAN", "url": "https://www.amazon.com/dp/B0BZS779MC", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 6.39, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Buy box read on 2026-10-04; seller: GUOHONGZHAN; availability: In Stock. Upstream short link https://a.co/d/5u90NVp." } ] } ] }, "robotis-fpx330-h101-idler": { "name": "ROBOTIS FPX330-H101 hinge frame and idler (per idler)", "unit": "each", "spec_summary": "X330 hinge frame with idler, sold as a set of four with bolts and nuts.", "manufacturer": "ROBOTIS", "mpn": "FPX330-H101", "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "Unit is one hinge frame + idler; the set is a pack of four.", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "FPX330-H101 4pcs Set", "url": "https://www.robotis.us/fpx330-h101-4pcs-set/", "publisher": "ROBOTIS AMERICA", "locator": "Product structured data (schema.org Offer) and package contents", "finding": "Price, availability and package contents in the product page.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "ROBOTIS America (linked from Koch README)", "url": "https://www.robotis.us/fpx330-h101-4pcs-set/", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 10, "pack_qty": 4, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "robotis-fpx330-h101-4pcs-set", "supplier": "ROBOTIS America", "url": "https://www.robotis.us/fpx330-h101-4pcs-set/", "region": "US", "observations": [ { "observation_id": "robotis-2026-10-04", "currency": "USD", "pack_price": 11.27, "pack_qty": 4, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "ROBOTIS America US store; shipping calculated at checkout, not established.", "notes": "schema.org Offer price 11.27 USD, availability http://schema.org/InStock." } ] } ] }, "robotis-fpx330-s101-frame": { "name": "ROBOTIS FPX330-S101 side frame (per frame)", "unit": "each", "spec_summary": "X330 side frame, sold as a set of four with bolts and nuts.", "manufacturer": "ROBOTIS", "mpn": "FPX330-S101", "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "Unit is one side frame; the set is a pack of four.", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "FPX330-S101 4pcs Set", "url": "https://www.robotis.us/fpx330-s101-4pcs-set/", "publisher": "ROBOTIS AMERICA", "locator": "Product structured data (schema.org Offer) and package contents", "finding": "Price, availability and package contents in the product page.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "ROBOTIS America (linked from Koch README)", "url": "https://www.robotis.us/fpx330-s101-4pcs-set/", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 7, "pack_qty": 4, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "robotis-fpx330-s101-4pcs-set", "supplier": "ROBOTIS America", "url": "https://www.robotis.us/fpx330-s101-4pcs-set/", "region": "US", "observations": [ { "observation_id": "robotis-2026-10-04", "currency": "USD", "pack_price": 10.01, "pack_qty": 4, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "ROBOTIS America US store; shipping calculated at checkout, not established.", "notes": "schema.org Offer price 10.01 USD, availability http://schema.org/InStock." } ] } ] }, "robotis-hn11-i101-idler": { "name": "ROBOTIS HN11-I101 idler set (XL430)", "unit": "each", "spec_summary": "Idler bearing set for DYNAMIXEL XL430: one idler, cap and bolts; hinge frame not included.", "manufacturer": "ROBOTIS", "mpn": "HN11-I101", "identity_sources": [ "S001", "S003" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" }, { "id": "S002", "type": "upstream", "title": "Koch README commit history and price presence scan", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commits/main/README.md", "publisher": "Alexander Koch", "locator": "Commits touching README.md; presence of the cost figures at each revision", "finding": "The cost figures are present in every revision from 265535c (2024-04-07) to the newest.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S003", "type": "vendor", "title": "HN11-I101 Set", "url": "https://www.robotis.us/hn11-i101-set/", "publisher": "ROBOTIS AMERICA", "locator": "Product structured data (schema.org Offer) and package contents", "finding": "Price, availability and package contents in the product page.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-koch-readme", "supplier": "ROBOTIS America (linked from Koch README)", "url": "https://www.robotis.us/hn11-i101-set/", "region": "US", "observations": [ { "observation_id": "koch-readme-0602b0c", "currency": "USD", "pack_price": 7, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2024-04-07", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S002" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Koch README \"Required Materials\" cost column at pinned revision 0602b0c. The figures ($258 and $183 totals; $100 for 2 XL430, $96 for 4 XL330-M288, $144 for 6 XL330-M077) are present in every README revision from 265535c (2024-04-07) to the newest (retained source evidence), so the price is dated to that earliest revision. Per-unit figures divide the listed line cost by its quantity." } ] }, { "offer_id": "robotis-hn11-i101-set", "supplier": "ROBOTIS America", "url": "https://www.robotis.us/hn11-i101-set/", "region": "US", "observations": [ { "observation_id": "robotis-2026-10-04", "currency": "USD", "pack_price": 8.05, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "ROBOTIS America US store; shipping calculated at checkout, not established.", "notes": "schema.org Offer price 8.05 USD, availability http://schema.org/InStock." } ] } ] }, "serial-bus-servo-driver-board": { "name": "Serial bus servo driver board (Waveshare-type, USB)", "unit": "each", "spec_summary": "USB serial bus servo adapter/driver board for ST/SC series bus servos, as linked by upstream (ASIN B0CTMM4LWK).", "manufacturer": null, "mpn": null, "identity_sources": [ "S001", "S002" ], "substitutes": [], "notes": "Upstream names this \"Motor Control Board\"; the listing is currently sold by a third-party seller.", "sources": [ { "id": "S001", "type": "upstream", "title": "SO-ARM100 README bill of materials", "url": "https://github.com/TheRobotStudio/SO-ARM100/blob/5f6d2b876a53a4872e405b991dd925556c9e38a4/README.md", "publisher": "TheRobotStudio", "locator": "Sourcing Parts: Parts for One Follower Arm; Parts For Two Arms", "finding": "Lists part names, amounts and US unit costs with purchase links.", "accessed_at": "2026-10-04" }, { "id": "S090", "type": "upstream", "title": "SO-ARM100 README commit history and price presence scan", "url": "https://github.com/TheRobotStudio/SO-ARM100/commits/main/README.md", "publisher": "TheRobotStudio", "locator": "Commits touching README.md; presence of 13.89, 121.94 and 229.88 at each revision", "finding": "The three figures are present in every revision from 2415d54 (2025-06-02) to the pinned revision.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S002", "type": "vendor", "title": "Serial Bus Servo Driver Board, Support 253 ST/SC Serial Bus Servos", "url": "https://www.amazon.com/dp/B0CTMM4LWK", "publisher": "Amazon.com", "locator": "Buy box: price, availability, seller", "finding": "Current listing price and availability as fetched.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-readme-amazon", "supplier": "Amazon listing linked from upstream README", "url": "https://www.amazon.com/dp/B0CTMM4LWK", "region": "US", "observations": [ { "observation_id": "readme-5f6d2b8", "currency": "USD", "pack_price": 10.6, "pack_qty": 1, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2025-06-02", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S090" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Upstream README \"Unit Cost (US)\" column at pinned revision 5f6d2b8 (2026-09-23). The figures (13.89 servo; 121.94 and 229.88 totals) appear unchanged in every README revision from 2415d54 (2025-06-02) to the pinned revision (20 consecutive revisions; retained source evidence), so the price is dated to that earliest revision. Supplier MOQ not independently checked; the table prices single units for the listed amount." } ] }, { "offer_id": "amazon-b0ctmm4lwk", "supplier": "Wonrabai Electronics", "url": "https://www.amazon.com/dp/B0CTMM4LWK", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 12.47, "pack_qty": 1, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S002" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Listing page fetched and buy box read on 2026-10-04; seller: Wonrabai Electronics." } ] } ] }, "small-bar-clamp": { "name": "Small bar / trigger clamp for mounting the arm base", "unit": "each", "spec_summary": "Small quick-grip bar clamp (about 4-6 inch) used to clamp the arm base to a table; upstream links two different products.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001" ], "substitutes": [], "notes": "Different clamp products are treated as one generic need, as upstream does.", "sources": [ { "id": "S001", "type": "upstream", "title": "SO-ARM100 README bill of materials", "url": "https://github.com/TheRobotStudio/SO-ARM100/blob/5f6d2b876a53a4872e405b991dd925556c9e38a4/README.md", "publisher": "TheRobotStudio", "locator": "Sourcing Parts: Parts for One Follower Arm; Parts For Two Arms", "finding": "Lists part names, amounts and US unit costs with purchase links.", "accessed_at": "2026-10-04" }, { "id": "S090", "type": "upstream", "title": "SO-ARM100 README commit history and price presence scan", "url": "https://github.com/TheRobotStudio/SO-ARM100/commits/main/README.md", "publisher": "TheRobotStudio", "locator": "Commits touching README.md; presence of 13.89, 121.94 and 229.88 at each revision", "finding": "The three figures are present in every revision from 2415d54 (2025-06-02) to the pinned revision.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S002", "type": "vendor", "title": "TAODAN 4PCS 4 Inch Trigger Quick Grip Clamps Bar Clamp Trigger Quick Grip Clamp Single Hand Ratchet Woodworking Clamp for Wood Bonding Processes", "url": "https://www.amazon.com/dp/B0DJNXF8WH", "publisher": "Amazon.com", "locator": "Buy box", "finding": "Current price and availability.", "accessed_at": "2026-10-04" }, { "id": "S003", "type": "vendor", "title": "Mr. Pen- Bar Clamps for Woodworking, 6\", 2 Pack, Orange", "url": "https://www.amazon.com/dp/B092L925J4", "publisher": "Amazon.com", "locator": "Buy box", "finding": "Current price and availability.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-readme-taodan-4pack", "supplier": "Amazon listing linked from upstream README (two-arm table)", "url": "https://www.amazon.com/dp/B0DJNXF8WH", "region": "US", "observations": [ { "observation_id": "readme-5f6d2b8", "currency": "USD", "pack_price": 9, "pack_qty": 4, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2025-06-02", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S090" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Upstream README \"Unit Cost (US)\" column at pinned revision 5f6d2b8 (2026-09-23). The figures (13.89 servo; 121.94 and 229.88 totals) appear unchanged in every README revision from 2415d54 (2025-06-02) to the pinned revision (20 consecutive revisions; retained source evidence), so the price is dated to that earliest revision. Supplier MOQ not independently checked; the table prices single units for the listed amount." } ] }, { "offer_id": "upstream-readme-mrpen-2pack", "supplier": "Amazon listing linked from upstream README (follower table)", "url": "https://www.amazon.com/dp/B092L925J4", "region": "US", "observations": [ { "observation_id": "readme-5f6d2b8", "currency": "USD", "pack_price": 5, "pack_qty": 2, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2025-06-02", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S090" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Upstream README \"Unit Cost (US)\" column at pinned revision 5f6d2b8 (2026-09-23). The figures (13.89 servo; 121.94 and 229.88 totals) appear unchanged in every README revision from 2415d54 (2025-06-02) to the pinned revision (20 consecutive revisions; retained source evidence), so the price is dated to that earliest revision. Supplier MOQ not independently checked; the table prices single units for the listed amount." } ] }, { "offer_id": "amazon-b0djnxf8wh", "supplier": "Partstock", "url": "https://www.amazon.com/dp/B0DJNXF8WH", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 9.99, "pack_qty": 4, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S002" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Listing page fetched and buy box read on 2026-10-04; seller: Partstock." } ] }, { "offer_id": "amazon-b092l925j4", "supplier": "Mr. Pen", "url": "https://www.amazon.com/dp/B092L925J4", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 7.95, "pack_qty": 2, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S003" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Listing page fetched and buy box read on 2026-10-04; seller: Mr. Pen." } ] } ] }, "soldering-iron": { "name": "Soldering iron with solder", "unit": "each", "spec_summary": "Basic soldering iron and solder, needed to attach wires to the voltage reducer.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001" ], "substitutes": [], "notes": "Required tool for the follower; reference option not yet chosen.", "sources": [ { "id": "S001", "type": "upstream", "title": "Koch low_cost_robot README bill of materials", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "publisher": "Alexander Koch", "locator": "Follower Arm / Leader Arm: Required Materials", "finding": "Lists parts, costs and purchase links for the follower and leader arms.", "accessed_at": "2026-10-04" } ], "offers": [] }, "usb-a-to-usb-c-cable": { "name": "USB-A to USB-C cable", "unit": "each", "spec_summary": "USB-A to USB-C data/charging cable, about 2 m; sold as a 2-pack.", "manufacturer": null, "mpn": null, "identity_sources": [ "S001", "S002" ], "substitutes": [], "notes": "", "sources": [ { "id": "S001", "type": "upstream", "title": "SO-ARM100 README bill of materials", "url": "https://github.com/TheRobotStudio/SO-ARM100/blob/5f6d2b876a53a4872e405b991dd925556c9e38a4/README.md", "publisher": "TheRobotStudio", "locator": "Sourcing Parts: Parts for One Follower Arm; Parts For Two Arms", "finding": "Lists part names, amounts and US unit costs with purchase links.", "accessed_at": "2026-10-04" }, { "id": "S090", "type": "upstream", "title": "SO-ARM100 README commit history and price presence scan", "url": "https://github.com/TheRobotStudio/SO-ARM100/commits/main/README.md", "publisher": "TheRobotStudio", "locator": "Commits touching README.md; presence of 13.89, 121.94 and 229.88 at each revision", "finding": "The three figures are present in every revision from 2415d54 (2025-06-02) to the pinned revision.", "accessed_at": "2026-10-04", "attribution_note": "Scan produced with the GitHub contents API on 2026-10-04." }, { "id": "S002", "type": "vendor", "title": "etguuds 6.6ft USB A to USB C Cable, 2Pack Fast Charging Cord Type C Charger", "url": "https://www.amazon.com/dp/B0B8NWLLW2", "publisher": "Amazon.com", "locator": "Buy box: price, availability, seller", "finding": "Current listing price and availability as fetched.", "accessed_at": "2026-10-04" } ], "offers": [ { "offer_id": "upstream-readme-amazon", "supplier": "Amazon listing linked from upstream README", "url": "https://www.amazon.com/dp/B0B8NWLLW2", "region": "US", "observations": [ { "observation_id": "readme-5f6d2b8", "currency": "USD", "pack_price": 7, "pack_qty": 2, "moq_packs": 1, "stock": "unknown", "source_checked_at": "2026-10-04", "price_observed_at": "2025-06-02", "price_date_basis": "earliest_unbroken_revision", "stock_observed_at": null, "check_method": "upstream_reported", "link_status": "unknown", "source_ids": [ "S001", "S090" ], "shipping_note": "Upstream table states item prices only; delivery and tax not stated.", "notes": "Upstream README \"Unit Cost (US)\" column at pinned revision 5f6d2b8 (2026-09-23). The figures (13.89 servo; 121.94 and 229.88 totals) appear unchanged in every README revision from 2415d54 (2025-06-02) to the pinned revision (20 consecutive revisions; retained source evidence), so the price is dated to that earliest revision. Supplier MOQ not independently checked; the table prices single units for the listed amount." } ] }, { "offer_id": "amazon-b0b8nwllw2", "supplier": "etguuds", "url": "https://www.amazon.com/dp/B0B8NWLLW2", "region": "US", "observations": [ { "observation_id": "amazon-2026-10-04", "currency": "USD", "pack_price": 7.19, "pack_qty": 2, "moq_packs": 1, "stock": "in_stock", "source_checked_at": "2026-10-04", "price_observed_at": "2026-10-04", "stock_observed_at": "2026-10-04", "check_method": "manual", "link_status": "working", "source_ids": [ "S002" ], "shipping_note": "Amazon US listing; shipping and sales tax depend on address and membership, not established.", "notes": "Listing page fetched and buy box read on 2026-10-04; seller: etguuds." } ] } ] } }, "sources": [ { "id": "S001", "title": "Koch arm build guide and BOM", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md", "finding": "BOM tables list $258 follower and $183 leader; opening approximations are $250 and $180. Lists actuators, printing, assembly, voltage setup and example scripts.", "type": "upstream", "locator": "README.md", "accessed_at": "2026-09-30", "publisher": "Alexander Koch / low_cost_robot contributors", "attribution_note": "" }, { "id": "S002", "title": "Repository MIT license", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/LICENSE", "finding": "MIT repository root license; purchased electronics and external artifacts are not assigned this license.", "type": "license", "locator": "LICENSE", "accessed_at": "2026-09-30", "publisher": "Alexander Koch / low_cost_robot contributors", "attribution_note": "" }, { "id": "S003", "title": "Repository snapshot", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/commit/0602b0c1e6a67d8f6ab96f81d1378639018d98af", "finding": "Pinned default-branch commit; release API returned no published stable release. Repository metadata is not independent adoption evidence.", "type": "upstream", "locator": "0602b0c1e6a67d8f6ab96f81d1378639018d98af", "accessed_at": "2026-09-30", "publisher": "Alexander Koch / low_cost_robot contributors", "attribution_note": "" }, { "id": "S004", "title": "Mechanical and control source inventory", "url": "https://github.com/AlexanderKoch-Koch/low_cost_robot/tree/0602b0c1e6a67d8f6ab96f81d1378639018d98af/hardware", "finding": "Follower and leader directories contain STL, STEP and Fusion assemblies; source tree contains Python control and simulation files.", "type": "upstream", "locator": "hardware/, dynamixel.py and simulation.py", "accessed_at": "2026-09-30", "publisher": "Alexander Koch / low_cost_robot contributors", "attribution_note": "" }, { "id": "S005", "type": "secondary", "title": "Koch arm US cost and sourcing estimate receipt", "url": "https://opensourcerobotics.dev/assets/build-guides/koch-arm-cost-estimate.json", "publisher": "Open Source Robotics", "locator": "Rollups as of 2026-10-04", "accessed_at": "2026-10-04", "finding": "Line-level US offers, price dates, printed-part slicing and rollups for the Koch arm configurations." }, { "id": "S006", "title": "Low-Cost Robot Arm Assembly (YouTube video)", "url": "https://www.youtube.com/watch?v=RckrXOEoWrk", "finding": "Video 'Low-Cost Robot Arm Assembly' uploaded by the YouTube channel 'Alexander Koch' (https://www.youtube.com/@alexkoch_ai). Linked from README.md in AlexanderKoch-Koch/low_cost_robot at revision 0602b0c1e6a6. The uploader is treated as the project's own channel because the channel name matches the project or maintainer name. The video is listed as a demonstration link; its content was not reviewed for technical accuracy.", "type": "maintainer", "locator": "YouTube video; linked from README.md in AlexanderKoch-Koch/low_cost_robot at revision 0602b0c1e6a6", "accessed_at": "2026-10-04", "publisher": "Alexander Koch", "attribution_note": "" } ] }