Robot arm joints (LeRobot SO-ARM101)
smart servo used for the LeRobot SO-ARM101 arm (Seeed listing): 5 kg·cm rated / 19.5 kg·cm stall at 7.4 V, 1:345, 52 rpm no-load, 12-bit absolute encoder.
Engineering inference
Feetech
Feetech STS3215-C001 19.5 kg·cm Servo
Feetech STS3215-C001 is the 7.4 V serial bus servo used in the LeRobot SO-ARM101 arm: 19.5 kg·cm stall and 5 kg·cm rated torque at 7.4 V, 52 rpm no-load, 1:345 copper gear train, 12-bit magnetic encoder (4096 steps, 0.088°), TTL bus up to 1 Mbps with IDs 0–253, 4–7.4 V, 55 g, 45.2 × 24.7 × 35 mm. Do not run it on 12 V: over-voltage protection trips above 8 V.
STS3215-C001Development boardPrice · lowest of 2 sellers$20.00www.seeedstudio.com · in stock
Buy at www.seeedstudio.com - www.seeedstudio.comin stock$20.00
- aifitlab.comin stock$23.00
Overview
Motor essentials
Facts about the complete product. Unknown values remain open design questions.
- Rated voltage
- 7.4 V
- No-load speed
- 52 RPM
- Gear reduction
- 345:1
- Encoder
- 12-bit magnetic, 360° (4096 per turn, 0.088°)
A good fit for
Guidance to help you shortlist. The basis is shown for each recommendation.
Robotics and motor control
daisy-chained TTL bus (IDs 0–253, up to 1 Mbps) with position, speed, load, voltage, current and temperature feedback and four modes incl. closed-loop speed.
Engineering inferenceNo-load speed, rated performance and stall limits describe different operating points. A stall specification is not a continuous operating rating.
3D model & CAD
3D model & CAD files
Generated from the datasheet's dimensioned drawing and measured against it. Download the STEP to check fit in your own enclosure.
- Envelope (L × W × H)
- 45.2 × 24.7 × 35 mm
- Verification
- generated
- Envelope complete
- Yes
Torque & control
Torque, speed and control
What the joint can deliver and how the controller talks to it.
- Type
- SMART_SERVO
- Rated / peak torque
- 0.49033 / 1.9123 N·m
- No-load speed
- 52 rpm
- Encoder
- 12-bit magnetic, 360° (4096 per turn, 0.088°)
- Control
- TTL · position (servo mode), closed-loop speed, open-loop speed, step, multi-turn position
| Connector | Type |
|---|---|
| ttl_bus | TTL bus, Molex 5264-type 3-pin 2.54 mm (×2, daisy-chain), 15 cm cable |
Rated torque is continuous; peak torque is short-duration. Values with two figures (e.g. 24/48 V) are per supply voltage.
Specifications
Motor performance
No-load, rated-load and stall figures retain their separate test conditions.
- Rated voltage
- 7.4 V
- No-load speed
- 52 RPM
- Continuous rated torque
- 0.49033 N·m
- Rated current
- 0.65 A
Stall torque and current are not continuous ratings. Check the duty cycle and starting load when choosing the driver and power supply.
Thermal limits by level
Product operating conditions, chip ambient ratings, package case limits and junction maxima remain separate.
Motor body
- Product operating range
- -20 to 60 °C
Mechanical dimensions
Reported product dimensions may exclude protruding components. Unknown height does not establish a complete clearance envelope.
- Length
- 45.2 mm
- Width
- 24.7 mm
- Reported height / thickness
- 35 mm
Attached generated geometry is an approximate envelope. A generated outline does not establish an electrically verified PCB footprint.
Board connectors
| ID / type | Pins | Pitch | Notes |
|---|---|---|---|
| ttl_busTTL bus, Molex 5264-type 3-pin 2.54 mm (×2, daisy-chain), 15 cm cable | 3 | Unknown | — |
Software and certifications
- Recorded certifications
- RoHS, EMC
Complete structured record
Every available field, including details beyond the summaries. Null means the value has not been established.
Sourcing & files
Supplier offers
US / USD is the target market. Observed price and stock are separate from a delivery quote.
www.seeedstudio.com
US · USD
$20.00Minimum quantity unknown
- Observed stock
- in stock
- Checked
- Oct 6, 2026, 07:06 AM UTC
- Delivery estimate
- Not quoted
Observed within the last 24 hours. Confirm the current supplier quote.
Visit supplier (opens in a new tab)aifitlab.com
US · USD
$23.00Minimum quantity unknown
- Observed stock
- in stock
- Checked
- Oct 6, 2026, 07:23 AM UTC
- Delivery estimate
- Not quoted
Observed within the last 24 hours. Confirm the current supplier quote.
Visit supplier (opens in a new tab)Delivery depends on quantity, postal code and shipping method. A dispatch statement such as “ship today” is not an arrival estimate.
Design files and references
Each source keeps its own verification status. Confirm the part revision and file contents before using it in a design.
Datasheet (opens in a new tab)
Manufacturer reference
Feetech STS3215-C001 servo — product photo (Seeed Studio) (opens in a new tab)
Manufacturer reference
inspected: black case printed FEETECH STS3215, copper 25T output spline; Seeed's C001 listing photo (file name carries SKU 108090023). The page JSON-LD image is a C046 photo — not used.
STEP (generated from datasheet drawing) — link unavailable
Generated asset
cad_check passed
Generated envelope geometry may also exist for this record. It does not replace manufacturer CAD or a verified electrical land pattern.
Source evidence
Document provenance, retrieval dates and the field groups supported by each source.
Supports: spec.compliance.certifications, spec.constraints.electrical.supply_voltage_max_v, spec.constraints.electrical.supply_voltage_min_v, spec.constraints.thermal.operating_temp_max_c, spec.constraints.thermal.operating_temp_min_c, spec.geometry.body_length_mm, spec.geometry.cad.bbox.height_mm, spec.geometry.cad.bbox.length_mm, spec.geometry.cad.bbox.width_mm, spec.geometry.cad.envelope_complete, spec.geometry.cad.mesh_path, spec.geometry.cad.step_path, spec.geometry.cad.verification, spec.geometry.dimensions.height_mm, spec.geometry.dimensions.length_mm, spec.geometry.dimensions.width_mm, spec.geometry.other.weight_g, spec.provides.actuator_type, spec.provides.backlash_deg, spec.provides.control_interface, spec.provides.control_modes, spec.provides.encoder, spec.provides.encoder_bits, spec.provides.features, spec.provides.gear_ratio, spec.provides.integrated_driver, spec.provides.kt_nm_per_a, spec.provides.motor_type, spec.provides.no_load_speed_rpm, spec.provides.peak_torque_nm, spec.provides.rated_torque_nm, spec.usage.connectors, spec.usage.pinout, spec.usage.pinout_complete, spec.usage.requirements.other.peak_current_a, spec.usage.requirements.rated_current_a, spec.usage.requirements.rated_voltage_v
sha256 291f59ae59fcbefa9a05c1943647c56b613c2a02127440ced9a40231d45f595d
Supports: offers
Supports: offers
FAQ
Feetech STS3215-C001 19.5 kg·cm Servo questions
What voltage powers the Feetech STS3215-C001 19.5 kg·cm Servo?
Supply range 4–7.4 V.
How much does the Feetech STS3215-C001 19.5 kg·cm Servo cost?
From $20 at www.seeedstudio.com (2 supplier offers tracked). Prices are observed unit prices before tax and shipping.
What are the Feetech STS3215-C001 19.5 kg·cm Servo dimensions?
45.2 × 24.7 × 35 mm. A STEP model is available for enclosure fit checks.
Where does this Feetech STS3215-C001 19.5 kg·cm Servo data come from?
Every value in this record is traced to a source — 3 documents including the board and chip datasheets — with the page and table cited per value. Unknowns are left explicit, never guessed.