Waveshare 5+1 DOF High-Torque Serial Bus Servo Robotic Arm Kit
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Waveshare 5+1 DOF High-Torque Serial Bus Servo Robotic Arm Kit
The RoArm-M3 is a 5 + 1 DOF high-torque serial bus servo robotic arm kit, based on ESP32. It features a 2-DOF wrist joint, supports flexible expansion and secondary development, wireless control, and is compatible with LeRobot for advanced AI applications.

Product Introduction
The RoArm-M3 series is a 5 + 1 DOF smart robotic arm designed for innovative applications. It features a lightweight structure with an effective payload of 0.2kg@0.5m, allowing flexible mounting on various mobile platforms. A 360° omnidirectional base combined with five flexible joints creates a workspace with a 1-meter diameter.
Its joint direct-drive design enhances repositioning precision and structural reliability, with innovative dual-drive technology doubling the shoulder joint torque. The onboard ESP32 MCU main control module supports multiple wireless control modes, providing extensive control interfaces and communication protocols for easy device connectivity.
A user-friendly, cross-platform WEB application offers a simple, visualized coordinate control mode for easy onboarding. Comprehensive graphic and video tutorials are provided for quick learning. Compatible with ROS2 and various host computers, it supports multiple wireless and wired communication modes. Expansion plates allow for customizing the EoAT (End of Arm Tooling) to meet diverse application requirements.
The RoArm-M3 series also supports the popular AI robotic arm project LeRobot, integrating its pretrained models, datasets with demonstrations, and simulation environments. This provides strong support for research in Deep Learning, Imitation Learning, and Reinforcement Learning. Developers can quickly deploy intelligent algorithms onto the RoArm-M3 using LeRobot's demos and algorithm libraries, expanding possibilities for innovative applications.
The RoArm-M3 series achieves an excellent balance between lightweight design, user-friendliness, expandability, and open innovation. It is a multi-functional robotic arm ideal for applications requiring flexibility, expandability, and ease of use, integrating intelligent control, human-machine interaction, and customizable development.
Version Options
Choose between the RoArm-M3-S and RoArm-M3-Pro. The RoArm-M3-Pro features 5 all-metal ST3235 bus servos, offering enhanced durability and stable backlash that does not increase with use.

Parameter Comparison

* Not including the weight of the table edge fixing clamp (290±10g).
Compatible with the popular AI robotic arm project - LeRobot
The RoArm-M3 robotic arm series seamlessly integrates with the open-source LeRobot framework on Hugging Face. This provides core resources including pretrained models, datasets from human demonstrations, and simulation environments. When paired with an N-VIDIA Jetson Orin NX motherboard or a PC with an N-VIDIA discrete GPU, users can experience the complete process of Imitation Learning and Reinforcement Learning projects.
Flexible Joints & Omnidirectional Space
Featuring a 360° rotation base and flexible joints, the RoArm-M3 creates an omnidirectional operating space with a 1-meter diameter, enabling free movement in all directions.
2 DOF Wrist Joint + EoAT for More Flexible Clamping
Equipped with a 2-DOF wrist joint offering pitch and horizontal rotation support, this robotic arm ensures seamless coordination with the End of Arm Tooling (EoAT) for multi-dimensional clamping and operation.

Easy to Control via Cross-platform Web Application
No app installation is required. Access and control the RoArm-M3 via a simple web application on mobile phones, tablets, or computers. This open-source Web App also supports secondary development for custom user interfaces and new functions.

Completely Open Source for Secondary Development
The control codes and communication interface documents for the RoArm-M3 series are fully open source, supporting secondary development across multiple languages and devices. Modularized demos and tutorials are provided to help beginners get started easily.

Joint Direct-Drive Design: Feedback Precision up to 0.088°
Achieve highly accurate joint angle feedback directly via a 12-bit high-precision magnetic encoder, without reduction groups. This allows for precise calculation of the actual position of the current target point based on feedback.

Innovative Dual-Drive Technology Doubles Shoulder Joint Torque
A specially developed dual-drive control algorithm enables two servos at the shoulder joint to coordinate their output torque effectively, significantly enhancing the power and overall load capacity of the RoArm-M3 Series.

Direct-Drive Clamp Enables Precise Force Control
The direct-drive clamp design allows precise programmatic control of clamping force, making it ideal for handling delicate objects without excessive pressure.

Dynamic External Force Adaptive Control
Enable this function to limit the maximum torque for each joint. If external force exceeds the configurable torque threshold, the robotic arm will rotate in response, returning to its specified position when the force decreases.

One-Click Automatic Recording: Easy to Create Actions
The RoArm-M3 can save JSON instructions for robot control as task files directly to the ESP32's Flash memory, ensuring data retention even without power. These task files allow the robotic arm to perform complex and repetitive operations.

Accurately Reach the Target by Entering Coordinates
Utilize the open-source inverse kinematics control algorithm in the three-dimensional Cartesian coordinate system. By inputting the target position, the robot arm accurately reaches the point by calculating each joint's rotation angle.

Curve Velocity Control for Smoother Movement
The curve velocity control algorithm ensures smoother and more natural robotic arm movement, eliminating oscillations during start and stop phases.

ESP-NOW Wireless Control: Low-Delay Remote Collaboration
ESP-NOW is a low-delay ad hoc wireless communication protocol that operates without network infrastructure. Control multiple robotic arms wirelessly with broadcast, group, or one-to-one control methods.

* Note: Broadcast control has no device limitations, while group control supports up to 20 devices. Refer to the WIKI for details.
Supports Leading-Following Control Mode Based on ESP-NOW
In Leading-following control mode, the Leader robotic arm transmits its joint angle information via ESP-NOW. Follower robotic arms then precisely imitate these actions in real time.

Multiple Control Interfaces, Multi-Device and Language Support
Beyond the WEB application, the RoArm-M3 series can be controlled via HTTP protocol network requests, serial communication, or USB communication, sending JSON commands and receiving feedback from various controllers.

Multiple Installation Methods for Integrating into Your Application
Various installation schemes and secondary development resources are provided, allowing flexible integration into diverse projects and applications.

Easy to Install Different Peripherals
The upper arm's main structure features two 1020 European standard aluminum rails, enabling easy installation of additional peripherals with boat nuts and M4 screws to meet specific needs.

Supports Installing a Camera to Extend Visual Applications
Includes a camera holder and open-source drawings. Directly install a compatible camera or adapt others for advanced visual applications.

* for reference only, only the LED light is included.
Onboard ESP32 Main Control Board
Features a powerful ESP32 main control MCU supporting multiple wireless communication protocols, with abundant open-source resources to facilitate secondary development of innovative applications.

Compatible with ROS2: Provides Model Establishment File and Supports Multi-Device Cooperation
Offers ROS2 communication nodes, a URDF model description file, and a beginner-friendly ROS2 tutorial.

Rich Tutorial Resources for Secondary Development
Comprehensive unit tutorials and cases covering various functions and common application scenarios are provided to help users quickly master secondary development.

General Driver Board for Robots
The onboard driver board features rich interfaces and resources for innovative development and functional expansion.

- ESP32-WROOM-32 controller module: Can be developed using Arduino IDE.
- IPEX 1 WIFI connector: For connecting WIFI antenna to increase wireless communication distance.
- LIDAR interface: Integrated LIDAR adapter function.
- I2C peripheral expansion interface: For connecting with OLED screen or other I2C sensors.
- Reset Button: Press and release to reboot the ESP32.
- Download button: Press when powering on to enter download mode.
- DC-DC 5V voltage regulator circuit: Provides power supply for host computers such as Raspberry Pi or Jetson Nano.
- Type-C port (LADAR): LIDAR data transmission.
- Type-C port (USB): ESP32 communication interface, for uploading programs to ESP32.
- XH2.54 power port: Supports DC 7~13V input, can directly power the serial bus servos and motors.
- INA219: Voltage/current monitoring chip.
- Power ON/OFF: External power supply ON/OFF.
- ST series serial bus servo interface: For connecting with ST3215 / ST3235 serial bus servo.
- Motor interface PH2.0 6P: Group B interface for motor with encoder.
- Motor interface PH2.0 6P: Group A interface for motor with encoder.
- Motor interface PH2.0 2P: Group A interface for motor without encoder.
- Motor interface PH2.0 2P: Group B interface for motor without encoder.
- AK09918C: 3-axis electronic compass.
- QMI8658C: 6-axis motion sensor.
- TB6612FNG: Motor Control Chip.
- Serial bus servo control circuit: For controlling multiple ST3215 serial bus servos and obtaining servos feedback.
- TF card slot: Can be used to store logs or WIFI configurations.
- 40PIN GPIO header: For connecting with Raspberry Pi or other host boards.
- 40PIN extended header: Easy to use the GPIO pins of Raspberry Pi or other host boards.
- CP-2102: UART to USB, for LIDAR data transmission.
- CP-2102: UART to USB, for ESP32 communication.
- Automatic download circuit: For uploading programs to the ESP32 without pressing the EN and BOOT buttons.
Diversified Onboard Resources Supports Function Expansion
Integrated with INA219 battery voltage monitoring and a 9-axis IMU sensor, enabling extensive function expansion and innovation.

Mouse Drag-and-Drop Interaction
Utilize Web applications and desktop software (open-source Python programs) to set action instructions with mouse presses and releases, providing flexible control over the robotic arm.

Specifications
| Feature | Detail |
|---|---|
| DOF | 5 + 1 |
| Work space | Horizontal diameter: 1120mm (Max, 360° omnidirectional), Vertical: 798mm (Max) |
| Operating voltage | 12V 5A power supply, supports 3S Lithium batteries (NOT included) |
| Load capacity | 0.2kg@0.5m |
| Repositioning precision | ~ 5mm |
| Servo rotation speed | 40rpm (no-load, no torque limit) |
| Operating range | BASE-360°, SHOULDER-180°, ELBOW-225°, HAND-135°/270° |
| Drive type | TTL Serial bus servo, direct-drive joint |
| Servo numbers | 7 |
| Joint angle sensor | 12-bit 360° magnetic encoder |
| Servo torque | 30KG.CM @12V, 20KG·CM @ 12V (EoAT) |
| Joint feedback information | servo status, joint angle, rotation speed, joint load, servo voltage, servo current, servo temperature and servo working mode |
| Main control | ESP32-WROOM-32 |
| Main control module features | WiFi, BT, Dual Core, 240MHz |
| Wireless control mode | 2.4G-WiFi, ESP-NOW |
| Wired control mode | USB, UART |
| Manual operation mode | WEB control interface |
| Host operation mode | UART / USB / WEB commands in JSON data format |
| Host support | USB connection devices such as Raspberry Pi, Jetson Orin Nano, and PC. |
| EoAT function | clamp function by default, can be changed as an additional degree of freedom |
| LED power | ≤1.5W |
| OLED screen size | 0.91inch |
| Other functions | 2-ch 12V power supply switch, 9-DOF IMU |
| Robotic arm weight | RoArm-M3-S: 973.5±15g RoArm-M3-Pro: 1020.8g±15g (Not including the weight of the table edge fixing clamp) |
| Table edge fixing clamp weight | 290±10g |
| Supported table edge thickness of the clamp | 72mm |
| Demo | 3D Cartesian coordinate system control (inverse kinematics control); Dynamic external force adaptive control; Joint angle control; Operating information feedback; FLASH files system operation; Steps recording and replaying; ESP-NOW control; Leading-Following mode (Hand guiding control); LED control; 12V power supply ON/OFF control; WiFi function settings; Set startup tasks; Serial bus servo settings; Feedback mode setting, etc. (Note: Please refer to the WIKI for more details) |
Product & Packaging Show

Dimensions

1. General Shipping Information
- We provide premium shipping methods with a tracking number for each order.
- Shipping addresses must be entered in English without special symbols to help the courier company recognize your address in the system. We will ship strictly according to the shipping address you provided. Please notify us of any address change before your order is marked "Shipped" to avoid parcel loss.
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- We can ship all in-stock orders within 1 business day after your order has been confirmed.
- All items are inspected before dispatch and are carefully hand-packed.
- With standard courier practice, you need to check the contents of the parcel before signing for your goods. Otherwise, we will not be held responsible for any damage that may have occurred in transit.
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2. Shipping Rates & Options
Our shipping rates are calculated based on the order value and destination. Please refer to the tables below for details.
2.1 Germany (Domestic)
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| Deutsche Post | €0 - €50.00 | €4.95 | 2-4 Business Days |
| Deutsche Post | Over €50.00 | Free | 2-4 Business Days |
|
DHL Paket (Faster Delivery) |
€0 - €50.00 | €6.95 | 1-3 Business Days |
|
DHL Paket (Faster Delivery) |
€50.00 - €100.00 | €2.00 | 1-3 Business Days |
|
DHL Paket (Faster Delivery) |
Over €100.00 | Free | 1-3 Business Days |
2.2 European Union (EU)*
*Including:
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| Deutsche Post | €0 - €100.00 | €7.95 | 5-9 Business Days |
| Deutsche Post | Over €100.00 | Free | 5-9 Business Days |
|
DHL Paket (Faster Delivery) |
€0 - €100.00 | €15.95 | 3-7 Business Days |
|
DHL Paket (Faster Delivery) |
€100.00 - €250.00 | €7.95 | 3-7 Business Days |
|
DHL Paket (Faster Delivery) |
Over €250.00 | Free | 3-7 Business Days |
2.3 United States
| Region | Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|---|
|
Continental U.S. (50 States) |
USPS Ground Advantage | €0 - €45.00 | €4.95 | 3-7 Business Days |
| USPS Ground Advantage | Over €45.00 | Free | 3-7 Business Days | |
| USPS Priority Mail | €0 - €45.00 | €16.95 | 1-4 Business Days | |
| USPS Priority Mail | Over €45.00 | €14.95 | 1-4 Business Days | |
|
Non-Continental U.S. (AK, HI, PR, etc.) |
USPS Ground Advantage | €0 - €60.00 | €6.95 | 5-9 Business Days |
| USPS Ground Advantage | Over €60.00 | Free | 5-9 Business Days |
* The regions in the Non-Continental U.S. include: Alaska, American Samoa, Guam, Hawaii, the Marshall Islands, the Northern Mariana Islands, Palau, Puerto Rico, the U.S. Virgin Islands, and all U.S. Armed Forces addresses. The shipping and delivery to these areas are subject to the Non-Continental U.S. shipping rules.
2.4 International (Outside EU)
For specific international destinations, including Switzerland, United Kingdom, and Norway.
| Order Amount | Shipping Cost |
|---|---|
| €0 - €300.00 | €19.95 |
| Over €300.00 | Free |
Important Notice:
- Inventory Status: Please check the inventory status on the product page. Our system displays real-time stock for our Munich and Long Beach warehouses. If an item is out of stock in these locations, it will be marked as "Pre-order". You can still place an order for these items.
- Pre-order Fulfillment: For "Pre-order" items, we arrange the most efficient logistics solution to ensure you receive your goods as quickly as possible. Your package may be shipped directly from our Shenzhen warehouse. Alternatively, as part of our standard restocking process, we may transport the goods to our Munich or Long Beach warehouse first (typically taking 5-10 business days) before dispatching them to you.
- Split Shipments: If your order contains both in-stock and Pre-order items, we will prioritize shipping the in-stock items from the local warehouse immediately. The remaining Pre-order items will be sent to you in a separate shipment once they are ready.
3. International Warehouse
Our products are stored in our Munich, Long Beach, and Shenzhen warehouses to provide more flexible logistics solutions tailored to different regions and customer needs. On each product's description page, we indicate the specific warehouse location to help you better plan your purchase and delivery schedule.
3.1 German Warehouse
For products stored in our warehouse in Munich, we use either Deutsche Post or DHL for shipping, depending on the size of the package. Logistics within Germany are very efficient, with an estimated delivery time of 2-4 business days, ensuring you receive your order quickly and conveniently. For Western EU countries, the estimated delivery time is 4-6 business days. For Eastern EU countries, the estimated delivery time is 6-8 business days.
3.2 US Warehouse
For products stored in our warehouse in Long Beach, we use either USPS or UPS for shipping, depending on the size of the package. Logistics within U.S. are very efficient, with an estimated delivery time of 3-7 business days, ensuring you receive your order quickly and conveniently.
3.3 Chinese Warehouse
For Pre-order items or orders fulfilled directly from our Shenzhen warehouse, we utilize YunExpress for reliable international shipping. Given the complexities of international shipping, the estimated delivery time for these packages is around 10 business days, though this may vary slightly due to customs processes or other uncontrollable factors. Otherwise, products will be restocked to our Munich or US warehouses before final delivery, as detailed in the "Important Notice" above.
4. Customs and Taxes
4.1 How are customs handled by OpenELAB for import or export?
For EU Member States: Whether shipped from Germany or China, we cover all import duties and taxes (DDP), ensuring that you receive your package without any additional costs or hassle with customs.
For countries outside of the European Union, such as Switzerland and Norway, you may be subject to import duties, taxes, and/or customs fees charged upon delivery. These fees vary from country to country and are the sole responsibility of the recipient.
⚠️ Refusal of Delivery: If you refuse to pay these fees upon delivery and the package is returned to us, the refund amount will be calculated after deducting the original shipping costs, return shipping costs, and any applicable customs or storage fees.
4.2 How is VAT charged when the Customer places an order from OpenELAB?
In accordance with the newest VAT e-commerce rules in the EU, OpenELAB shall have the right to charge the amount of VAT at checkout. The standard rate of actual VAT applied is subject to the destination country's regulations. No additional VAT will be charged upon delivery for these orders.
Effective Date: December 10, 2025
At OpenELAB, we are committed to providing accurate product descriptions and high-quality electronics. The following policy outlines your rights and obligations, designed to be fair to both our customers and our business operations globally.
1. Warranty Policy
A. Standard Limited Warranty (Global & US)
For customers in the United States, Asia, and other non-EU regions:
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Warranty Period: OpenELAB provides a 12-month warranty from the date of delivery.
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Coverage: This warranty covers defects in material and workmanship under normal use.
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Resolution: We will repair or replace defective units at no charge.
B. Statutory Rights for EU/UK Customers (EU Compliance)
If you are a consumer residing in the European Union or the UK purchasing from our global site:
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Statutory Guarantee: You are entitled to a 24-month statutory guarantee for conformity defects present at the time of delivery, in accordance with EU consumer protection laws.
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Relation: The Standard Limited Warranty (Section 1.A) applies in addition to, and does not replace, your statutory rights.
C. Warranty Exclusions (Applies to ALL Regions)
Warranty coverage is VOID if the damage is caused by:
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Misuse: Incorrect installation, reverse polarity, or exceeding voltage limits.
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Unauthorized Modification: This explicitly includes soldering, cutting pins, modifying the PCB, or flashing unauthorized/beta firmware that "bricks" the device.
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Physical Damage: Drops, moisture/water damage, or electrical surges (lightning).
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Normal Wear & Tear: Consumable parts (e.g., batteries), unless defective upon arrival.
Note: For non-warranty repairs (e.g., customer-induced damage), we may offer repair services for a fee. Shipping and diagnostic costs will be borne by the customer.
2. Return & Refund Policy
A. Return Window
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Standard: You may request a return within 30 days of receiving your order.
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EU Customers: You have the statutory right to withdraw from the contract within 14 days of receipt without giving a reason.
B. Refund Conditions & Restocking Fees
To protect against policy abuse, the refund amount is strictly determined by the condition of the returned item.
1. Full Refund (100%)
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The item is Brand New, Unopened, and Unused.
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The original packaging is intact and sealed.
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All accessories are present.
2. Partial Refund (Restocking Fee / Value Depreciation)
If the item is returned in a condition that prevents it from being sold as new, OpenELAB reserves the right to deduct a Restocking Fee (or "Compensation for Loss of Value" for EU customers) from the refund.
Deductions apply if:
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Signs of Use: Visible scratches, mounting marks on screw holes, or fingerprints.
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Damaged Packaging: Original box is torn, written on, or missing.
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Technical Modification: The device has been powered on, programmed/flashed, or soldered.
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Broken Seals: Anti-static bags or security seals have been opened.
Depending on the severity of the usage/damage, the deduction may range from 15% to 50% of the product price. Items damaged beyond repair due to misuse will not be refunded.
C. Shipping Costs
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Defective / Wrong Item: OpenELAB covers the return shipping cost.
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Customer Remorse (Changed Mind / Ordered Wrong Item): The customer is responsible for all return shipping costs to our designated return center (located in the US, Germany, or China, depending on your region). Original shipping fees are non-refundable unless required by local law.
3. Return Process (RMA)
To ensure a smooth return process, please follow these steps:
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Authorization: Contact us at info@openelab.io before returning any item. Returns without prior authorization will not be accepted.
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RMA Number: We will provide you with a Return Merchandise Authorization (RMA) number and the correct return address.
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Packing: Ship the item back in its original packaging with the RMA number clearly marked on the shipping label (not on the product box).
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Tracking: We strongly recommend using a trackable shipping method. OpenELAB is not responsible for returns lost in transit.





