Klaw
Meet Klaw! A versatile robotic arm designed and Manufactured by Yudu Robotics - a company focused on making robotics easy and fun to learn. Klaw is a table top robotic arm designed to mimic the movement of a human arm. It is designed to be programmed as well as be controlled by knobs located at its base. It is equipped with servos and is designed to be lightweight yet durable, allowing it to pick up and move objects with ease and precision. Klaw is suitable for young engineers, hobby projects, basic repetitive tasks and educational purposes.
Getting started
Klaw Anatomy :
The structural components include the links, joints, and base, all working together to support the arm's movements.
- Links: Klaw features aluminum alloy links that connect the various joints, providing necessary support and stability. Their specific lengths and dimensions are tailored for optimal reach and flexibility.
- Joints: Powered by nylon-geared servos, Klaw's joints are critical pivot points allowing the arm to bend and rotate with four degrees of freedom. The servos have a clutch mechanism that slips under excess load, reducing wear and tear on the gears.
- Base: Klaw’s aluminum alloy base provides stability and houses the control knobs, anchoring the arm securely to a surface. It includes power supply connections and interfaces for additional plug-ins.
- End Effector: The end effector is designed to grip, lift, and manipulate items with precision. Its specific design allows for secure handling of various objects, making it essential for efficient task performance.
Mechanical
Material:
The external body of the Klaw is made up of durable powder coated aluminum-alloy (AL5052). This has been done considering the following reasons:
- Corrosion resistant
- Enhanced Durability
- Easy Maintenance
- Aesthetically appealing
- Lightweight yet strong structure
Degree of freedom :
Klaw has 4 degrees of freedom.
Base Servo: This servo allows rotational movement around the vertical axis, letting the entire arm swivel left or right.
Three Arm Servos: Each of these servos can extend or retract the arm, changing the position of different links.
(Add an image explaining the different sides the servo can move)
Gripper and its Add-Ons :
The gripper is operated using a Servo. It controls the opening and closing of the gripper, allowing the gripper to grasp or release objects.
Klaw’s end effector can be enhanced with add-ons, such as an actuator like electromagnets for pick-and-place tasks or a sensor such as a camera can be attached to expand Klaw’s capabilities for more complex operations.
Work Environment :
Klaw has a maximum reach of 1 foot around 180 degrees. The servos used are capable of rotating 300 degrees, enabling a wide range of movement. Klaw is designed to handle a maximum payload of 100 grams and can manage objects with a maximum width of 5 cm.
Payload Specifications :
Klaw is designed to handle a maximum recommended payload (Object) of 100 grams, meaning it can lift and move objects up to this weight. Additionally, Klaw can manage objects with a maximum size of 5cm width.
Electronics
Motherboard :
General spec:
Klaw features an advanced Motherboard designed with ESP32 microcontroller. It includes 2 GPIO ports, 2 Dc motor ports, 6 servo ports and POTs Features of Klaw’s MOTHERBOARD:
| Category | Specification |
| PCB Name | PeeCee |
| Processor | Esp 32 s3 module |
| Memory | 4MB flash memory |
| Connectivity | Bluetooth, usb (wifi can be used but it is not compatible with plode app ATM) |
| Power Consumption | 9V 3A (adaptor only) |
| GPIO ports | 2 |
| Pins | 2 dc motor, 6 servos, 6 pots |
Map:
( insert schematic of the Connections from PCB to servo, Additional ports , etc)
Motors:
Klaw utilizes nylon-geared servos to power its movements. These servos are crucial for providing the precise and powerful movements needed for the robotic arm to function effectively. They are servos which have a clutch mechanism. Here are the detailed specifications and features of the servos used in Klaw:
- Torque: ___ kg-cm, providing strong and reliable movement. This high torque enables Klaw to lift and manipulate objects up to its maximum payload capacity without strain.
- Type: Nylon-geared, ensuring durability and longevity. Nylon gears offer a balance between cost and performance, making them suitable for applications that require frequent usage without the added cost of metal gears.
- Clutch Mechanism: When there is excess load on the servos, the clutch mechanism slips, which reduces wear and tear of the gears. This ensures smooth operation and prevents damage to the servos under high load conditions.
- Control: PWM (Pulse Width Modulation) is used to adjust the position and speed of the servos by varying the width of electrical pulses. This method allows for precise control over the servo's movement, ensuring accurate positioning and smooth transitions between movements.
These servos are integral to Klaw's performance, providing the necessary power, precision, and durability to handle a wide range of tasks effectively.
Other motors considered for Klaw were stepper motors, known for their efficiency and smooth operation in robotic arms. However, the significant drawback was their cost, which would have considerably raised the cost price of Klaw. Thus, the choice to use nylon-geared servos was made to ensure a balance between performance and cost-effectiveness.
Caution: These high capacity Servo motors have moving parts that can create pinch points. Fingers or other body parts caught between moving components can cause injury. Always ensure that hands and other body parts are kept away from moving parts while the servo is operating.
| Specification | Details |
| Type | PWM |
| Quantity | 5 |
| Stall Torque | |
| Rated torque | |
| Pulse Width | 50Hz (20ms period) |
| Control signal | 1ms to 2ms |
| no load current | |
| Stall current | |
| Gear Type | Nylon gears - clutch based |
| Operating vol | 5V (Maximum 7.5V) |
| Rotation Angle | 300 degrees .01 resolution |
| Dimensions |
PWM (Pulse Width Modulation):
PWM is a technique used to control the servos in Klaw. It works by sending a series of electrical pulses to the servos. The width of these pulses determines how much the servo turns or moves. By adjusting the pulse width, PWM helps control the exact position and speed of Klaw’s movements.
Power spec :
Klaw is powered by a 9v 3Ah adaptor. It needs to be connected to a power source while working and does not have a Battery option.
External Plug-ins:
Klaw can be enhanced with various external plug-ins, such as ultrasonic sensors, LEDs, displays, etc. These plug-ins connect to the GPIO pins on the Motherboard, expanding Klaw’s capabilities and allowing for more complex and interactive functions.
Control Methods:
Klaw can be controlled in several ways:
● Hardware Knobs:
Located next to the base of Klaw, these knobs allow for direct manual control of the arm. This method follows the servo constraints, including angle restrictions, to ensure safe operation.
● Plode App:
Klaw can also be controlled using the Plode app. This app provides a convenient way to manage Klaw’s movements and tasks, but it also adheres to the servo constraints, including angle limits, for safe and accurate operation.
visit, Plode for more information.
There are different ways to use Klaw through the Plode app.
- Joystick option
- block programming
- python programming
- Refer Plode for more information.
● IDEs:
For advanced users with programming skills, IDEs offer more flexibility by allowing users to bypass the standard servo constraints imposed by the Plode app and hardware knobs. This is ideal for users who want to customize Klaw's movements beyond the default restrictions. IDEs such as Arduino IDE can be used.
FAQs
1. What materials are used to construct Klaw?
Klaw is made from durable powder-coated aluminum alloy, which is corrosion-resistant, lightweight, and aesthetically appealing.
2. How many degrees of freedom does Klaw have?
Klaw has four degrees of freedom:
- Base Servo: Rotational movement around the vertical axis.
- Three Arm Servos: Extend or retract the arm, changing the position of different links.
3. What kind of servos does Klaw use?
Klaw uses nylon-geared servos with a clutch mechanism. These servos provide precise and powerful movements while reducing wear and tear under excess load.
4. What is the maximum payload Klaw can handle?
Klaw is designed to handle a maximum payload of 100 grams and can manage objects with a maximum size of 5cm width.
5. How is Klaw controlled?
Klaw can be controlled using:
- Hardware knobs located at its base.
- The Plode app, which offers joystick control, block programming, and Python programming.
- IDEs like the Arduino IDE for advanced programming beyond standard constraints.
6. What safety precautions should be taken when using Klaw?
Users should keep fingers and other body parts away from moving components to avoid injury. The servo motors have moving parts that can create pinch points.
7. Can Klaw be enhanced with add-ons?
Yes, Klaw's end effector can be enhanced with add-ons like electromagnets for pick-and-place tasks or sensors such as cameras for more complex operations.
8. What are the dimensions and weight of Klaw?
9. How do you connect and configure external plug-ins?
10. What kind of power supply is required for Klaw?
11. What is the maximum reach of Klaw's arm?
12. Are there any tutorials or support available for beginners?
13. How is Klaw shipped, and what is included in the box?
14. How do you update the firmware of Klaw?