The Feetech STS3215-C044 is a 1/191 gear-ratio TTL serial bus servo for SO-ARM101 leader-arm joints and compact robot motion control. It combines a magnetic-encoder serial bus servo architecture with a metal gear train and TTL communication for robotics projects that need addressable position control rather than a basic PWM-only servo. This configuration is listed with 27.4kg.cm @ 7.4V stall torque, a 1/191 gear ratio, and 7.4V operation. Use it with a compatible Feetech TTL serial bus controller or software stack, and confirm the selected power system before integrating it into a robot arm or custom mechanism. Features TTL serial bus control - Supports addressable servo control for multi-axis robotics and compact automation. Magnetic encoder feedback - Provides position feedback for closed-loop servo operation. 27.4kg.cm @ 7.4V stall torque - Matches the listed torque class for this SKU. 1/191 gear ratio - Helps identify the correct version for SO-ARM or custom joint selection. Metal gear drivetrain - Built for repeated motion in robotic mechanisms. 3-pin TTL servo connector - Designed for Feetech serial bus wiring rather than standard PWM-only control. Multi-servo system support - Suitable for robot arms and mechanisms that require multiple servos on a shared control bus. Feedback and protection workflow - Feetech serial bus servos can report key operating data through the protocol when supported by the controller. Specifications Parameter Value Model Feetech STS3215-C044 SKU Feetech-STS3215-C044 Operating Voltage 7.4V Stall Torque 27.4kg.cm @ 7.4V Gear Ratio 1/191 Control Interface TTL serial bus, 3-pin servo connector Feedback Magnetic encoder servo feedback Gear Type Metal gear drivetrain Primary Fit / Use SO-ARM101 Variant Options Variant SKU Confirmed Difference Default Title Feetech-STS3215-C044 Single Shopify variant for Feetech STS3215-C044; confirm voltage, torque class, and gear ratio before integration. Product Visuals Servo product view Servo body detail Connector and cable detail Mounting and gear housing detail Package or accessory view Reference Documents Feetech Serial Bus Servo Communication Protocol Application SO-ARM robotic arm builds - Use where the selected voltage, gear ratio, and torque class match the arm design. Leader and follower arm joints - Select the correct ratio version for each joint role in the mechanism. Educational robotics - Build and teach serial bus servo control, ID assignment, and feedback-based motion. Desktop automation - Drive compact grippers, pan-tilt modules, and low-load motion fixtures. Multi-servo prototypes - Develop addressable joint chains using a compatible TTL serial bus controller. Maintenance and replacement - Replace a matching Feetech servo only after confirming the exact SKU, voltage, and gear ratio. Packing List Description Quantity Feetech STS3215-C044 TTL serial bus servo 1 FAQ .faq-accordion details { border-bottom: 1px solid #e6eef8; padding: 14px 0; } .faq-accordion summary { list-style: none; cursor: pointer; font-size: 16px; font-weight: 700; color: #1f2933; position: relative; padding-right: 32px; } .faq-accordion summary::-webkit-details-marker { display: none; } .faq-accordion summary::after { content: "\203A"; position: absolute; right: 4px; top: 50%; transform: translateY(-50%) rotate(90deg); color: #007fff; font-size: 28px; line-height: 1; transition: transform 0.2s ease; } .faq-accordion details[open] summary::after { transform: translateY(-50%) rotate(270deg); } .faq-accordion p { margin: 12px 0 0; color: #4b5563; line-height: 1.65; } What is the main use of the Feetech STS3215-C044? The Feetech STS3215-C044 is a TTL serial bus servo for robotics, compact automation, and multi-servo motion-control systems. It is listed for SO-ARM101, but wiring, ID assignment, voltage, and software configuration should still be checked before installation. Which voltage should be used? Use the selected servo within its listed voltage range: 7.4V. Do not mix voltage versions in the same build unless the power architecture is designed for it. What gear ratio does this version use? This version is listed with a 1/191 gear ratio, so it should be selected according to the required joint torque, speed, and control feel. Does it use a standard PWM hobby-servo signal? No. This is a TTL serial bus servo. Plan for a compatible Feetech serial bus controller or interface, correct wiring, and proper servo ID configuration. Can multiple servos share the same bus? Feetech serial bus servos are designed for bus-style control, but each servo should have a unique ID and the power bus must be sized for the total current draw. What is included in the package? The packing list confirms one Feetech STS3215-C044 servo. Extra controller boards, brackets, cables, power supplies, and arm hardware are not included unless separately stated by the selected kit. What should be checked before integration? Confirm voltage, connector pinout, servo ID, control mode, mechanical mounting, load, travel limits, and heat/current margins before installing the servo in a robot joint. Is this waterproof? No waterproof or IP rating is confirmed for this listing, so it should be used in a dry, protected environment unless additional protection is designed into the system.
