--- title: "Leaderdrive LCS series cup-type reducer specs" description: "Leaderdrive LCS cup-shaped strain-wave reducer family with keyed or Oldham-coupled input options; select frame, ratio and input variant." canonical: https://actuatorlist.com/actuators/leaderdrive-lcs last-updated: 2026-11-01T14:05:43.000Z --- # LCS series (cup-type harmonic reducer) by Leaderdrive (Suzhou Leader Harmonic Drive) > Leaderdrive LCS cup-shaped strain-wave reducer family with keyed or Oldham-coupled input options; select frame, ratio and input variant. ## Specifications | Spec | Value | | --- | --- | | Category | Harmonic / Precision | | Peak torque | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Rated torque | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Max speed | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Gear ratio | 50:1-160:1: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Weight | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Torque density | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Price | quote only: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Price per Nm | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Backdrivable | Legacy catalog placeholder; not a measured family rating. See engineering notes. | | Backlash | Legacy catalog placeholder; not a measured family rating. See engineering notes. | | Voltage | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Peak current | n/a: Family-level catalog value; confirm frame, ratio and variant. Reducer/sensor assembly, not an integrated motor and drive. | | Communication | n/a | | Control modes | n/a | | Encoder | Legacy catalog placeholder; not a measured family rating. See engineering notes. | | Integrated driver | no | | Availability | in production | | Data status | Family-level evidence: confirm variant | ## Use cases - robot arm - cobot joint - industrial robot joint ## Engineering notes Family-level evidence reviewed October 1, 2026. Manufacturer-published data is not independent bench validation. Examples below are not selected inventory SKUs; existing catalog fields are not replaced with family ranges. ### Manufacturer specifications LCS uses a standard cup-shaped flexspline. LCS-I has keyed input; LCS-II uses an Oldham coupling. LCSG is a separate strengthened family. [Leaderdrive LCS, Models](https://www.leaderdrive.com/product/6.html). ### Conditions and revision conflicts Frame 20, ratio 100 is an example, not a complete SKU. The [website table](https://www.leaderdrive.com/product/6.html) lists rated 40 Nm, start-stop 82 Nm, maximum average load 49 Nm, maximum peak 147 Nm and maximum input 6,500 rpm. The [LCS-I manual, PDF page 2 in ZIP](https://www.leaderdrive.com/uploadfile/file/20250725/1753419635322738.zip) instead lists 38 Nm at 2,000 rpm, start-stop 78 Nm, average 47 Nm, momentary 140 Nm and maximum input 6,000 rpm. Rating conditions and applicable revision need confirmation; do not combine them into SKU limits. ### Engineering inference The [LCS geometry archive](https://www.leaderdrive.com/uploadfile/file/20250728/1753661078125719.zip) contains STEP and Parasolid geometry. Drawings and source-qualified mechanical tables support partial modeling, not a calibrated dynamics or thermal model. Inference assumes the selected drawing and applicable revision are confirmed. Confidence in model completeness is low; no numerical efficiency, cooldown or precision estimate is defensible from this evidence. ### Unknown / confirmation required Numerical product-specific efficiency, cooling hardware, repeated thermal duty/derating, externally measured loaded output repeatability and calibrated simulation support remain unconfirmed in the reviewed material. Unknown is not zero. Encoder or sensor resolution is not output accuracy. Motor voltage, current and motor constants are not applicable to a reducer alone; select a motor/drive separately. Use the [robot actuator selection guide](/guides/robot-actuator-selection) to define the missing measurements and acceptance criteria. ## Sources - [https://www.leaderdrive.com/product/6.html](https://www.leaderdrive.com/product/6.html) - [https://www.leaderdrive.com/uploadfile/file/20250725/1753419635322738.zip](https://www.leaderdrive.com/uploadfile/file/20250725/1753419635322738.zip) - [https://www.leaderdrive.com/uploadfile/file/20250728/1753661078125719.zip](https://www.leaderdrive.com/uploadfile/file/20250728/1753661078125719.zip) - [https://aifitlab.com/products/leaderdrive-lcs-i-strain-wave-gear](https://aifitlab.com/products/leaderdrive-lcs-i-strain-wave-gear) - [https://www.step.parts/parts/leaderdrive\_lcs\_i\_series\_lcs\_14\_xxx\_c\_ii](https://www.step.parts/parts/leaderdrive_lcs_i_series_lcs_14_xxx_c_ii) - [https://m.made-in-china.com/product/Leaderdrive-Lcs-II-Series-Harmonic-Drive-Speed-Reducer-for-Industrial-Robotics-774005585.html](https://m.made-in-china.com/product/Leaderdrive-Lcs-II-Series-Harmonic-Drive-Speed-Reducer-for-Industrial-Robotics-774005585.html) ## Similar Harmonic / Precision actuators - [EC-A5013-H17-100 (ENCOS)](https://actuatorlist.com/actuators/encos-ec-a5013-h17-100): 142.9 Nm/kg - [EC-A3814-H14-107 (ENCOS)](https://actuatorlist.com/actuators/encos-ec-a3814-h14-107): 138.2 Nm/kg - [LPA-20 (Low Profile Rotary Actuator) (Harmonic Drive LLC)](https://actuatorlist.com/actuators/harmonic-drive-lpa-20): 40.7 Nm/kg - [FHA-14C-100 (FHA-C Mini) (Harmonic Drive LLC)](https://actuatorlist.com/actuators/harmonic-drive-fha-14c-100): 17 Nm/kg - [SHA-CG series (SHA-CG Hollow Shaft Actuator) (Harmonic Drive LLC)](https://actuatorlist.com/actuators/harmonic-drive-sha-cg): n/a ## Machine-readable - JSON: https://actuatorlist.com/api/v1/actuators/leaderdrive-lcs - Catalog index for agents: https://actuatorlist.com/llms.txt