Seventeen added actuation records. Zero removed claim IDs. Independent verification unchanged at six.

The direct answer

Where did the catalog grow? Between the immutable v0.4.14 release (2026-08-13) and the current v0.4.15 release (2026-08-19), the catalog added 17 exact component records — 103 to 120 — and 10 catalog-linked manufacturers — 45 to 55: seven manufacturers new to the catalog plus three existing directory profiles (TQ-RoboDrive, FAULHABER and Elmo Motion Control) linked by their first exact records. Unlike the previous window, which spread 27 records across all five hardware layers, this wave is deliberately narrow: all 17 additions carry the motion-actuation category, taking that layer from 26 to 43 records and from 256 to 516 claims. The other four layers did not change by a single record or claim.

Did evidence quality improve? No — evidence volume grew, evidence quality did not. Of the 260 added claims, 225 entered as manufacturer-claimed (M) and 35 as explicit unknowns (U). Zero entered as independently verified: V stayed at 6, RCI-derived stayed at 1 and conflicting stayed at 6. A catalog that is 16.5 percent larger contains exactly as many independently verified values as before, and RCI ran zero physical tests in this window.

What was preserved? Every one of the 945 claim IDs in v0.4.14 appears in v0.4.15 with identical serialized metadata. Zero claim IDs were removed, zero were modified, all 260 added claims sit on the 17 new records, and the six published comparisons carried over unchanged.

Where the 17 records landed: three actuation clusters

The wave was cut as three batches, and the frozen JSON preserves the split. Deltas sum exactly: 6 + 5 + 6 = 17 records, 88 + 78 + 94 = 260 claims and 11 + 12 + 12 = 35 unknowns.

Seven manufacturers enter the catalog with this wave: Unitree Robotics, FEETECH, Damiao, Leaderdrive and Laifual Drive, headquartered in China, and mjbots and ODrive Robotics, headquartered in the United States. The five Chinese entries are a coverage statement and nothing more — the catalog now records their published boundaries next to Harmonic Drive, Nabtesco, Kollmorgen, TQ-RoboDrive, maxon, FAULHABER and Elmo records, and no record in the release asserts that any pair of products is a substitute or an equivalent.

Two additions are deliberate near-duplicates: FEETECH ST-3215-C001 and ST-3215-C018 are separate records because the two order codes publish different electrical identities under one family name — 6–7.4 V operating range, 19.5 kg·cm stall at 6 V and copper gears for the C001 versus 4–14 V, 30 kg·cm stall at 12 V and steel gears for the C018. That exact-variant split is what the open SO-101 follower power-chain conflict note turns on: the catalog now carries both variants' published boundaries side by side, and the three-way supply-voltage conflict remains open with zero RCI physical tests.

The evidence mix: M and U grew, V, D and C did not move

Because zero existing claims changed state, the deltas decompose cleanly: the entire +225 in M and the entire +35 in U come from the 17 new records. The manufacturer-claimed share moved from 90.5 to 89.5 percent and the independently verified share from 0.6 to 0.5 percent — both purely by dilution. Of the 35 added unknowns, 17 are the per-record independent-validation field — every new record states explicitly that no independent test result was found for that exact model — and the remaining 18 are unpublished specification fields, such as the continuous-torque envelope the Unitree GO-M8010-6 and Damiao DM-J4310-2EC V1.2 records leave open next to their published 23.7 N·m and 12.5 N·m peak figures.

One torque set, two definitions: an unmerged reducer observation

Cataloging reducers side by side surfaced a definition boundary worth stating precisely. The Leaderdrive LCS size-20 ratio-100 row and the Laifual FSS size-20 ratio-100 row publish, on their own official pages, an identical four-value torque set: 40 N·m rated, 82 N·m start-stop peak, 49 N·m maximum average load and 147 N·m maximum momentary. But the identical numbers sit under non-identical definitions:

• Rated-speed condition. Laifual's column is labeled exactly "Rated torque at 2000r/min input". Leaderdrive's table carries a separate "Rated Input Speed" column reading 3,500 r/min for size 20. The two 40 N·m figures are therefore published against different stated input-speed conditions.
• Backlash class. Leaderdrive publishes ≤10 arcsec maximum backlash for size 20; Laifual publishes ≤20 arcsec. These are component specifications on different bounds, not measurements of the same quantity.

RCI records the two rows as two separate components with their own claim IDs and did not merge, rank or equate them. An identical torque set under different rated-speed definitions and different backlash classes is an observation about how specification tables are written — it is not evidence that the two gear units perform identically, and this brief makes no substitution claim for this or any other manufacturer pair.

What did not change, stated as boundaries

• 0 removed claim IDs. All 945 v0.4.14 claims persist in v0.4.15 with byte-identical serialized metadata. Zero removals is a revision-control observation for this window, not a promise.
• V unchanged at 6. The independent-verification layer did not grow while the actuation layer grew 65.4 percent. Depth in manufacturer-published boundaries is faster to add than verification, and this brief does not conflate the two.
• Comparisons unchanged at 6, membership unchanged at 21. The six new joint-module and bus-servo records carry the integrated-joint-actuators comparison-group tag — 21 to 27 tagged records — so their component pages point at the integrated joint actuator evidence table. The published table itself, however, still lists its original 21 members; extending its row set is future editorial work, not part of this release.
• 0 RCI physical tests. RCI has not operated, measured or benchmarked any of the 120 cataloged components. Every M record remains a manufacturer claim.

Method and limits

RCI compared the complete component and claim arrays in the frozen public v0.4.14 catalog and v0.4.15 catalog by stable ID. A component or claim ID present only in v0.4.15 is added; an ID present in both with different serialized metadata would be modified (observed: zero); an ID present only in v0.4.14 would be removed (observed: zero). Evidence-state, category and cluster tables are recomputed from the claim-level evidence codes and the component-level category field. Anyone with both files can reproduce every number on this page.

• This is a reproducible comparison of two published releases — the same recomputation work level as RCI 047's catalog delta — not hardware, firmware or SDK testing.
• Manufacturer-claimed values remain claims even when the citation is an official datasheet; inclusion in the catalog is not endorsement, availability, compatibility or verification.
• Two reducer records are bounded to a size-and-ratio table row rather than one complete orderable code, because the cited official pages publish parameter grids; each record states this boundary in its own claims.
• The window covers six days of cataloging in one category. Cluster and manufacturer deltas describe editorial coverage decisions inside that window and must not be read as market signals.
• Percentage shares are reported to one decimal from exact counts; all other figures are exact.

Download and reproduce Data Brief 004

Both compared releases are frozen and public: v0.4.14 catalog JSON with its claim-level CSV, and v0.4.15 catalog JSON with its claim-level CSV. The current-release aliases are components.json and components.csv; all machine-readable endpoints are listed on the data page, and the browsable records live on the component catalog landing page.

Suggested citation: Robot Component Index. “Actuation Depth Wave 1 Catalog Delta: 17 Added Motion Records, 260 Added Claims, 0 Removed IDs.” RCI 054 / Data Brief 004, 2026-08-19. https://robotcomponentindex.com/research/actuation-depth-wave-1-catalog-delta/

For evidence-state definitions, use the methodology. For the previous catalog delta, use RCI 047 / Data Brief 003. For version-aware BibTeX and machine citation records, use Cite RCI.