{
  "schema": "cad-agent-references/1",
  "built": "2026-11-04T22:52:31-08:00",
  "revision": "3a4ec137a2a7cf52fa6072b5bc81b7e320d49701",
  "area": {
    "slug": "gears",
    "title": "Gears",
    "domain": "mechanical",
    "scope": "Spur, helical, planetary and printed gear trains."
  },
  "fields": {
    "status": "`source`: read, with a dated `verified` note, and may be cited. `catalogued`: listed from a survey and not yet read; never cite one",
    "kind": "what the source is (research/references/vocab.yaml `kind`); a read source from before schema 2 has none",
    "evidence_class": "its rung on the evidence ladder, lowest first: snippet-only, read, verified-at-source, encoded, measured",
    "confidence": "#143: {level, estimate, sources}, derived from the evidence; `unknown` when the record has no evidence block",
    "licence": "{spdx, class, read, note}: `read: false` means the licence text was not read, only stated by the survey",
    "placed": "the docs/areas.yaml areas the record is listed in (`unplaced` when its areas match none)",
    "placed_note": "its row on the site, which [ref:<id>] in any page links to, is /references/<first placed area>#<id>",
    "vocab": "every coded value is explained in research/references/vocab.yaml"
  },
  "index": "https://cad-agent.valpatel.com/catalog/references/index.json",
  "count": 39,
  "coverage": [],
  "records": [
    {"id":"daguirreag-3d-printable-bearing-generator","kind":"project","category":"mechanisms","title":"3D-printable-bearing-generator","authors":[],"org":"DAguirreAg","year":null,"url":"https://github.com/DAguirreAg/3D-printable-bearing-generator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"GPL-3.0","class":"share-alike","read":false,"note":"The map states 'GPL-3.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","inserts"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Fusion script for printed ball races with bought balls.","assessment":{"built":"works","supply":"commodity","cost":"under100","make":"print","docs":"guide","activity":"dormant","role":"lessons","cad":{"seen":"U"},"answers":{"perf":"unknown","life":"not tested","print":"not stated"},"caveat":"Fusion 360 script only; no load, friction or life numbers.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"3ba8a8dab52fcf0f","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"sirojudinmunir-3d-printed-cycloidal-actuator","kind":"project","category":"mechanisms","title":"3D-printed-cycloidal-actuator","authors":[],"org":"sirojudinMunir","year":null,"url":"https://github.com/sirojudinMunir/3D-printed-cycloidal-actuator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"process_groups":["print","inserts"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Step-by-step assembly images and parts list.","assessment":{"built":"built","supply":"commodity","cost":"unknown","make":"print","docs":"guide","activity":"slow","role":"context","cad":{"seen":"F"},"answers":{"perf":"unknown","life":"unknown","print":"unknown"},"caveat":"No ratio, torque, materials or test data in the README text.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"98f8461270fc3794","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"littlemoomoodingdingcow-3d-printed-cycloidal-robotic","kind":"project","category":"mechanisms","title":"3D-Printed-Cycloidal-Robotic-Actuator","authors":[],"org":"LittleMooMooDingDingCow","year":null,"url":"https://github.com/LittleMooMooDingDingCow/3D-Printed-Cycloidal-Robotic-Actuator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"17:1 and 25:1 with a STEP file.","assessment":{"built":"built","supply":"commodity","cost":"unknown","make":"print","docs":"basic","activity":"active","role":"lessons","cad":{"seen":"V"},"answers":{"perf":"17:1 and 25:1; no torque figures","life":"none stated","print":"printed; material and settings not stated"},"caveat":"No test data; the 17:1 version is unmaintained and docs are partly external links.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"3ad894d9efcd3ff5","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"nikodembartnik-3d-printed-planetary-gearbox","kind":"project","category":"mechanisms","title":"3D-Printed-Planetary-Gearbox","authors":[],"org":"NikodemBartnik","year":null,"url":"https://github.com/NikodemBartnik/3D-Printed-Planetary-Gearbox","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'none stated'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","cnc"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Includes a torque test stand (Arduino and Python); no results published. The stand is reusable for other actuator tests.","assessment":{"built":"built","supply":"commodity","cost":"unknown","make":"print","docs":"basic","activity":"active","role":"lessons","cad":{"seen":"U"},"answers":{"perf":"ratios 4:1, 5:1, 25:1; no torque stated","life":"stand built for durability tests; no results","print":"not stated"},"caveat":"No results published; video link is a placeholder.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"b5341a2e386126de","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"hasslerengineering-3d-printed-strain-wave-gear","kind":"project","category":"mechanisms","title":"3D-Printed-Strain-Wave-Gear","authors":[],"org":"HasslerEngineering","year":null,"url":"https://github.com/HasslerEngineering/3D-Printed-Strain-Wave-Gear","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'none stated'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Hackaday Prize 2018 strain-wave gear. Old.","assessment":{"built":"unknown","supply":"unknown","cost":"unknown","make":"unknown","docs":"none","activity":"dormant","role":"context","cad":{"seen":"F"},"answers":{"perf":"unknown","life":"unknown","print":"unknown"},"caveat":"No README; note says it is old.","assessed":{"date":"2026-11-02","from":"note-only"}},"used_for":[],"imported":"7ba72311cd9ce17c","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"jelmerv-anti-backlash-cycloidal-actuator","kind":"project","category":"mechanisms","title":"Anti-Backlash Cycloidal Actuator","authors":[],"org":"JelmerV","year":null,"url":"https://github.com/JelmerV/Anti-Backlash-Cycloidal-Actuator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"share-alike","read":false,"note":"The map states 'CC BY-SA 4.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","sheet"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Thesis project with raw test data. Anti-backlash designs cut play but add friction.","assessment":{"built":"works","supply":"commodity","cost":"unknown","make":"print","docs":"full","activity":"dormant","role":"reference","cad":{"seen":"V"},"answers":{"perf":"unknown from README; see thesis results","life":"play and friction tested vs baseline; raw timestamped data","print":"3D-printed parts; material not stated in README"},"caveat":"Thesis prototype; the README gives no headline numbers, only pointers to raw data and notebooks.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"6fbc8663e404e7fc","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"anti-backlash-cycloidal-drives-twente-thesis","kind":"paper","category":"design-guides","title":"Anti-backlash cycloidal drives (Twente thesis)","authors":[],"org":"essay.utwente.nl","year":null,"url":"https://essay.utwente.nl/essays/103595","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'thesis'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Friction, backlash and stiffness against preload. Numbers not read.","used_for":[],"imported":"7795a1ef790001e2","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"dashs20-crap","kind":"project","category":"mechanisms","title":"CRAP cycloidal generator","authors":[],"org":"dashs20","year":null,"url":"https://github.com/dashs20/CRAP","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'none stated'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","cnc","inserts"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"build123d generator with collision checks and recorded clearances.","assessment":{"built":"concept","supply":"commodity","cost":"unknown","make":"print+cut","docs":"guide","activity":"active","role":"reference","cad":{"seen":"V"},"answers":{"perf":"unknown","life":"none stated","print":"STEP/STL export; settings by export_settings.json"},"caveat":"No physical build shown; correctness is judged by collisions only; AI-written code.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"7bc3c5d27180f405","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"cycloidal-drive-testing-forum","kind":"forum-thread","category":"design-guides","title":"Cycloidal drive testing (forum)","authors":[],"org":"canadianhobbymetalworkers.com","year":null,"url":"https://canadianhobbymetalworkers.com/threads/cycloidal-drive-design-testing.6756/","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'forum'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Delrin pins crushed after about an hour.","used_for":[],"imported":"e9a56808972782d3","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"zhangdong-cheku-3d-printed-cycloidal-drive-v1","kind":"project","category":"mechanisms","title":"Cycloidal Drive V1 (zhangdong)","authors":[],"org":"zhangdong-cheku","year":null,"url":"https://github.com/zhangdong-cheku/3D-Printed-Cycloidal-Drive-V1","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"STEP and STL. The README claims zero backlash and 5 arcmin or less, and lists steel, 8.5 kg and IP65 specs that do not fit a printed part.","assessment":{"built":"unknown","supply":"specialty","cost":"unknown","make":"machined","docs":"basic","activity":"slow","role":"context","cad":{"seen":"V"},"answers":{"perf":"100 N·m rated, 300 N·m peak, 90% efficiency claimed","life":"none tested; zero backlash vs <=5 arcmin contradictory","print":"not printed per spec (steel); no print settings"},"caveat":"Claims zero backlash and 5 arcmin or less; steel, 8.5 kg specs do not match a printed part.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"2104d96bd1e56017","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"zhangdong-cheku-3d-printed-cycloidal-drive-v2","kind":"project","category":"mechanisms","title":"Cycloidal Drive V2 (zhangdong)","authors":[],"org":"zhangdong-cheku","year":null,"url":"https://github.com/zhangdong-cheku/3D-Printed-Cycloidal-Drive-V2","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"Apache-2.0","class":"open","read":false,"note":"The map states 'Apache-2.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"STL only. Dual-disc idea; test data not published.","assessment":{"built":"unknown","supply":"unknown","cost":"unknown","make":"unknown","docs":"none","activity":"slow","role":"context","cad":{"seen":"V"},"answers":{"perf":"unknown","life":"unknown","print":"unknown"},"caveat":"Qualitative claims only; no test data, ratio or materials stated.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"9ebc182f7ff2578a","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"tom-ilan-cycloidal-gearbox","kind":"project","category":"mechanisms","title":"cycloidal_gearbox (tom-ilan)","authors":[],"org":"tom-ilan","year":null,"url":"https://github.com/tom-ilan/cycloidal_gearbox","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'none stated'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"9:1, 1.3 N·m and 66% efficiency with no method stated.","assessment":{"built":"works","supply":"commodity","cost":"unknown","make":"print","docs":"basic","activity":"active","role":"lessons","cad":{"seen":"F"},"answers":{"perf":"9:1; 1.3 N·m; 66% efficiency, no method","life":"none stated","print":"PLA on Bambu P1S, +0.15 mm tolerance offset"},"caveat":"9:1, 1.3 N·m and 66% efficiency are stated without a test method; no licence.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"74721eadd59e5ed1","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"fabbearing-jake-read","kind":"project","category":"mechanisms","title":"fabbearing (Jake Read)","authors":[],"org":"bio.cba.mit.edu","year":null,"url":"https://bio.cba.mit.edu/jakeread/fabbearing","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Large printed cross-roller and ball bearing, Fusion file.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"2e984d6847889f31","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"source-robotics-faze4-robotic-arm","kind":"project","category":"mechanisms","title":"Faze4 robotic arm","authors":[],"org":"Source-Robotics","year":null,"url":"https://github.com/Source-Robotics/Faze4-Robotic-arm","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'MIT / CERN-OHL-S-2.0 (conflict)'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"6-axis arm with printed cycloidal gearboxes. STEP, STL and URDF. The page shows two licences.","assessment":{"built":"replicated","supply":"commodity","cost":"unknown","make":"print+cut","docs":"full","activity":"slow","role":"reference","cad":{"seen":"V"},"answers":{"perf":"unknown","life":"low backlash claimed, no numbers","print":"printed; material not stated in README"},"caveat":"'Low backlash' is claimed with no numbers; the arm is weak next to commercial arms.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"45f82b09844fec16","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"praveenkum11-freecad-bearingswb","kind":"project","category":"components","title":"FreeCAD_BearingsWB","authors":[],"org":"PraveenKum11","year":null,"url":"https://github.com/PraveenKum11/FreeCAD_BearingsWB","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"GPL-3.0","class":"share-alike","read":false,"note":"The map states 'GPL-3.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","inserts"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Standard bearing dimensions plus a printable race and cage generator. No load ratings.","assessment":{"built":"works","supply":"commodity","cost":"unknown","make":"print","docs":"guide","activity":"active","role":"lessons","cad":{"seen":"V"},"answers":{"param":"Parametric FreeCAD workbench; CSV BOM export","valid":"Standard dims per ISO 15; no load validation"},"caveat":"Boundary dimensions only; no load ratings, and printable bearing performance not tested.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"1447fac2652838b1","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"fully-3d-printed-gear-drive-esk8-forum","kind":"forum-thread","category":"design-guides","title":"Fully 3D-printed gear drive (esk8 forum)","authors":[],"org":"forum.esk8.news","year":null,"url":"https://forum.esk8.news/t/fully-3d-printed-gear-drive-that-might-not-suck/4801?page=4","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'forum'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Tight backlash fails; runout varies backlash.","used_for":[],"imported":"e03b390fec634287","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"chrisspen-gears","kind":"project","category":"components","title":"gears (chrisspen)","authors":[],"org":"chrisspen","year":null,"url":"https://github.com/chrisspen/gears","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'NOASSERTION'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"OpenSCAD gear library: spur, herringbone, planetary, bevel, worm.","assessment":{"built":"replicated","supply":"commodity","cost":"unknown","make":"print","docs":"basic","activity":"active","role":"lessons","cad":{"seen":"V"},"answers":{"param":"Parametric OpenSCAD; STL export implied","valid":"DIN 867 20 degree pressure angle cited"},"caveat":"OpenSCAD fork; no strength or fit data in README.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"f4a0c9c0f9e29f6d","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"harmonic-vs-cycloidal-test-howtomechatronics","kind":"article","category":"design-guides","title":"Harmonic vs cycloidal test (HowToMechatronics)","authors":[],"org":"howtomechatronics.com","year":null,"url":"https://howtomechatronics.com/how-it-works/harmonic-vs-cycloidal-drive-designing-3d-printing-testing","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'article'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Printed torque, backlash and wear test. Results not read.","used_for":[],"imported":"27e80fab8f1c87be","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"robrotics-hd20","kind":"project","category":"mechanisms","title":"HD20 printed harmonic drive","authors":[],"org":"robrotics","year":null,"url":"https://github.com/robrotics/hd20","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"share-alike","read":false,"note":"The map states 'CC BY-SA 4.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","inserts"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"20:1 strain-wave drive with a cycloidal tooth profile. Load cell: 2.1 to 2.6 N·m, 48 to 58% efficiency, 18% unit-to-unit spread. Backlash not measured. Superseded by HDP30.","assessment":{"built":"works","supply":"commodity","cost":"under100","make":"print","docs":"full","activity":"active","role":"reference","cad":{"seen":"V"},"answers":{"perf":"20:1; 2.1-2.6 N·m at 0.7 A; efficiency 48-58%","life":"backlash not measured yet; PLA fatigue warning","print":"PLA; Super Lube PTFE grease; detailed settings not read"},"caveat":"Superseded by HDP30; README wrongly says HDP30 has no data; backlash unmeasured; it is strain-wave, not cycloidal.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"054e1e829db380e9","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"robrotics-hdp30","kind":"project","category":"mechanisms","title":"HDP30 printed strain-wave drive","authors":[],"org":"robrotics","year":null,"url":"https://github.com/robrotics/hdp30","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"share-alike","read":false,"note":"The map states 'CC BY-SA 4.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"process_groups":["print","sheet","cnc","inserts"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"30:1. STEP, DXF tooth profiles, Onshape. Load-cell test: ~0.03 degree backlash, held 1.49 N·m, 9,713 cycles at 1.3 N·m. Efficiency figures disagree on the page.","assessment":{"built":"works","supply":"commodity","cost":"under100","make":"print","docs":"full","activity":"active","role":"leader","cad":{"seen":"V"},"answers":{"perf":"30:1; held 1.49 N·m; efficiency 42-56% static (one table says 47-60%)","life":"backlash 0.03 deg; 9,713 flex cycles at 1.3 N·m, no damage","print":"PLA throughout incl. flexspline; Super Lube PTFE grease"},"caveat":"Flexspline cracks at 1.5-1.67 N·m; only 9,713 cycles tested; efficiency figures differ across the page.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"f2490481cbbf1bd5","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"nico-schluter-helicalgearplus","kind":"project","category":"components","title":"HelicalGearPlus","authors":[],"org":"nico-schluter","year":null,"url":"https://github.com/nico-schluter/HelicalGearPlus","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'NOASSERTION'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Fusion add-in: helical, herringbone, internal and worm gears.","assessment":{"built":"product","supply":"commodity","cost":"unknown","make":"unknown","docs":"basic","activity":"active","role":"context","cad":{"seen":"U"},"answers":{"param":"Parametric Fusion add-in; export formats unknown","valid":"No standard check stated"},"caveat":"Fusion 360 only; README shows no tolerance or fit validation.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"f6a1d408e0022adc","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"hybrid-polymer-ball-bearing-with-printed-races","kind":"paper","category":"design-guides","title":"Hybrid polymer ball bearing with printed races","authors":[],"org":"avesis.gazi.edu.tr","year":null,"url":"https://avesis.gazi.edu.tr/yayin/459511c0-2b77-4128-aeff-a326a6fbfa40/vibration-analysis-of-a-hybrid-polymer-ball-bearing-with-3d-printed-races","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'paper'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Vibration and rolling resistance; concludes a limited-life bearing.","used_for":[],"imported":"765a33963fd43e13","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"aaedmusa-internal-cycloidal-actuator","kind":"project","category":"mechanisms","title":"Internal-Cycloidal-Actuator","authors":[],"org":"aaedmusa","year":null,"url":"https://github.com/aaedmusa/Internal-Cycloidal-Actuator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'none stated'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"8:1, popular reference build.","assessment":{"built":"built","supply":"specialty","cost":"unknown","make":"needs-pcb-or-winding","docs":"basic","activity":"dormant","role":"lessons","cad":{"seen":"U"},"answers":{"perf":"8:1 ratio only","life":"none stated","print":"unknown"},"caveat":"README is a short description with one image; no test data or build guide.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"804b160ce8f6bf10","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"koshirorobot-internal-cycloidal-robotic-actuator","kind":"project","category":"mechanisms","title":"Internal-Cycloidal-Robotic-Actuator","authors":[],"org":"KoshiroRobot","year":null,"url":"https://github.com/KoshiroRobot/Internal-Cycloidal-Robotic-Actuator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"One clean STEP and a BOM.","assessment":{"built":"unknown","supply":"unknown","cost":"unknown","make":"unknown","docs":"guide","activity":"slow","role":"context","cad":{"seen":"V"},"answers":{"perf":"unknown","life":"unknown","print":"unknown"},"caveat":"No README was available; this answer rests on the summary alone.","assessed":{"date":"2026-11-02","from":"note-only"}},"used_for":[],"imported":"0763d25f40f850b7","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"parametric-ball-bearing-makerworld-2108208","kind":"project","category":"mechanisms","title":"Parametric ball bearing (MakerWorld 2108208)","authors":[],"org":"makerworld.com","year":null,"url":"https://makerworld.com/en/models/2108208-fully-parametric-customizable-ball-bearing-default","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Printed races and cage with steel balls; load and life claimed.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"bf909f60960a6218","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"pla-slewing-ring-with-wire-raceways","kind":"paper","category":"design-guides","title":"PLA slewing ring with wire raceways","authors":[],"org":"et-old.ippt.pan.pl","year":null,"url":"https://et-old.ippt.pan.pl/index.php/et/article/download/3133/2502","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'paper'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Axial stiffness against FEA. Attribution to this URL not confirmed.","used_for":[],"imported":"c67ecf3d9cb27cf5","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"mateuszdrwal-planetary-generator","kind":"project","category":"components","title":"Planetary-Generator","authors":[],"org":"mateuszdrwal","year":null,"url":"https://github.com/mateuszdrwal/Planetary-Generator","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"GPL-2.0","class":"share-alike","read":false,"note":"The map states 'GPL-2.0'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Tooth-count solver for planetary sets.","assessment":{"built":"unknown","supply":"unknown","cost":"unknown","make":"unknown","docs":"none","activity":"slow","role":"context","cad":{"seen":"U"},"answers":{"param":"unknown","valid":"unknown"},"caveat":"README is only a URL; function and accuracy unverifiable.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"2ea7c4e004faf315","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"printable-linear-bearing-reprap","kind":"project","category":"mechanisms","title":"Printable linear bearing (RepRap)","authors":[],"org":"reprap.org","year":null,"url":"https://reprap.org/wiki/Printable_linear_bearing","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Printed ball linear bearing iterations.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"c4f7c96df2c50110","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"printabot-3d-printed-ptfe-turntables","kind":"project","category":"mechanisms","title":"Printabot PTFE turntables","authors":[],"org":"Printabot","year":null,"url":"https://github.com/Printabot/3d-printed-ptfe-turntables","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"process_groups":["print","cnc"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Printed turntable using PTFE tube as the sliding race. 30 kg tested by the author; the 100 kg demo is not a rating.","assessment":{"built":"works","supply":"commodity","cost":"under100","make":"print","docs":"basic","activity":"active","role":"lessons","cad":{"seen":"F"},"answers":{"perf":"30 kg test load; 100 kg extreme test, not a rating","life":"not tested","print":"PLA rotor, PETG base, 0.4 nozzle, 2 walls, 15% infill"},"caveat":"Load tests informal; the 100 kg run is explicitly not a rating.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"da98e492974ec91d","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"printed-harmonic-drive-makerworld-402774","kind":"project","category":"mechanisms","title":"Printed harmonic drive (MakerWorld 402774)","authors":[],"org":"makerworld.com","year":null,"url":"https://makerworld.com/en/models/402774-harmonic-drive","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"25:1, 5 N·m claimed, PETG. Snippet only.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"a9fc77eddf7133be","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"printed-slewing-bearing-makerworld-217548","kind":"project","category":"mechanisms","title":"Printed slewing bearing (MakerWorld 217548)","authors":[],"org":"makerworld.com","year":null,"url":"https://makerworld.com/models/217548","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"non-commercial","read":false,"note":"The map states 'CC BY-NC-SA (per snippet)'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"64 mm roller slew bearing, 7 kg, little play. Snippet only.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"ca0bc7d6d43f9004","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"printed-thrust-bearing-bartneck-laimer-slew","kind":"project","category":"mechanisms","title":"Printed thrust bearing (Bartneck, Laimer slew)","authors":[],"org":"bartneck.de","year":null,"url":"https://www.bartneck.de/?p=3556","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Ball thrust bearing with drawing.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"73691e4409c8425b","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"slewing-bearing-makerworld-32748","kind":"project","category":"mechanisms","title":"Slewing bearing (MakerWorld 32748)","authors":[],"org":"makerworld.com","year":null,"url":"https://makerworld.com/en/models/32748-slewing-bearing","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'unverified'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"study-only"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Tapered-roller geometry.","assessment":{"cad":{"seen":"U"}},"used_for":[],"imported":"fee3f92f77baef17","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"sovol-printing-gears-that-work","kind":"article","category":"design-guides","title":"Sovol: printing gears that work","authors":[],"org":"sovol3d.com","year":null,"url":"https://www.sovol3d.com/blogs/news/3d-printing-gears-that-actually-work-backlash-orientation-and-material-tips","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'article'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"XY expansion; calibrate before setting backlash.","used_for":[],"imported":"bfe8cedb0133c5c4","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"testing-a-printed-cycloidal-gearbox-hackaday","kind":"article","category":"design-guides","title":"Testing a printed cycloidal gearbox (Hackaday)","authors":[],"org":"hackaday.com","year":null,"url":"https://hackaday.com/2026/08/01/testing-a-3d-printed-cycloidal-gearbox-design/","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'article'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"92% efficiency claimed by the author.","used_for":[],"imported":"51f52e5b8543283e","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"theseus-printed-friction-torque-limiter","kind":"paper","category":"design-guides","title":"Theseus: printed friction torque limiter","authors":[],"org":"theseus.fi","year":null,"url":"https://www.theseus.fi/handle/10024/910970","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":null,"class":"unclear","read":false,"note":"The map states 'thesis'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"none"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"measured"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Slip torque differed from theory with poor repeatability.","used_for":[],"imported":"985614e58dbef335","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"darrenlevine-tiptapmotor","kind":"project","category":"mechanisms","title":"TipTapMotor","authors":[],"org":"DarrenLevine","year":null,"url":"https://github.com/DarrenLevine/TipTapMotor","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"process_groups":["print","pcb"],"evidence":{"class":"snippet-only","numbers":"none"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"8:1 printed planetary in a 47 mm cube BLDC actuator. STL only.","assessment":{"built":"built","supply":"specialty","cost":"100to500","make":"needs-pcb-or-winding","docs":"guide","activity":"dormant","role":"lessons","cad":{"seen":"V"},"answers":{"perf":"unknown","life":"not stated","print":"Lulzbot Mini tight-tolerance Cura profile; material not stated"},"caveat":"No torque, backlash or life data; needs a custom DirectServo PCB.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"09ef4a2840c1d953","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"pzfreo-wormgear","kind":"project","category":"components","title":"wormgear (pzfreo)","authors":[],"org":"pzfreo","year":null,"url":"https://github.com/pzfreo/wormgear","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"process_groups":["print","cnc"],"evidence":{"class":"snippet-only","numbers":"claimed"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"build123d worm generator with DIN calculations and STEP export. README says it is AI-written.","assessment":{"built":"works","supply":"commodity","cost":"unknown","make":"print+cut","docs":"guide","activity":"active","role":"reference","cad":{"seen":"V"},"answers":{"param":"Parametric Python, build123d parts, STEP export","valid":"Checked against DIN-3975 calc and a textbook example; not certified"},"caveat":"README says AI-written; checks are self-consistency, not full DIN certification or physical tests.","assessed":{"date":"2026-11-02","from":"readme"}},"used_for":[],"imported":"98c160131cf5c171","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"},
    {"id":"xrobots-cycloidaldrive","kind":"project","category":"mechanisms","title":"XRobots CycloidalDrive","authors":[],"org":"XRobots","year":null,"url":"https://github.com/XRobots/CycloidalDrive","access":"free","terms":"cited and summarised, never copied","licence":{"spdx":"MIT","class":"open","read":false,"note":"The map states 'MIT'; the licence text was not read."},"reuse":{"text":"cite-only","geometry":"adapt-with-attribution"},"areas":["gears"],"domains":["drive"],"evidence":{"class":"snippet-only","numbers":"unknown"},"confidence":{"level":"low","estimate":0.4,"sources":1},"summary":"Versions V1 to V4 and a strain-wave folder.","assessment":{"built":"unknown","supply":"unknown","cost":"unknown","make":"unknown","docs":"none","activity":"dormant","role":"context","cad":{"seen":"F"},"answers":{"perf":"unknown","life":"unknown","print":"unknown"},"caveat":"README is only a title; nothing is verifiable from it.","assessed":{"date":"2026-11-02","from":"note-only"}},"used_for":[],"imported":"0746adffb7496fae","status":"catalogued","evidence_class":"snippet-only","placed":["gears"],"source_file":"research/references/projects-drive.yaml"}
  ]
}