Quick Answer
For a 2DOF robot arm claw, choose servos that provide at least 10 kg·cm torque for the base joint and 5 kg·cm for the gripper, with metal gears for durability. The 2DOF Robot Arm Manipulator Claw with 2x Servos comes pre-equipped with MG995 servos that meet these requirements out of the box.
Torque Requirements for Each Joint
The base (shoulder) joint must lift the entire arm and payload, so it needs the highest torque. The gripper joint only needs to close the claw and hold an object, requiring less torque. Underestimating torque leads to stalled servos and dropped objects.
Metal Gears vs Plastic Gears
Servos with metal gears handle shock loads better and last longer in a robot arm where the arm can bump into obstacles. Plastic gears may strip under repeated stress, especially in the gripper where the claw may encounter resistance.
Decision Rules for Servo Selection
- Torque Rule: Base joint: minimum 10 kg·cm for a standard hobby arm. Gripper joint: minimum 5 kg·cm. If your payload exceeds 100g, increase base torque by 2 kg·cm per 50g extra. Always calculate the worst-case lever arm length before finalizing torque.
- Gear Material Rule: Choose metal gears for any joint that will experience impact or continuous load. Plastic gears are acceptable only for very light, low-stress prototypes. Metal gears add weight; factor that into your torque calculation.
- Voltage and Controller Rule: Verify that your servo's operating voltage matches your controller (e.g., 5V for Arduino, 6V for many servo drivers). MG995 servos work at 4.8-7.2V, giving flexibility. Use a separate BEC if your servo current exceeds the controller's regulator capacity.
Product Spotlight
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2DOF Robot Arm Manipulator Claw with 2x Servos: This 2DOF aluminum robot arm clamp claw comes pre-fitted with two powerful MG995 servos, giving both tilt and grip control right out of the box. You get a ready-to-use arm without sourcing or wiring separate servos, saving time and ensuring compatibility for Arduino or Raspberry Pi projects.
2DOF Robot Arm Manipulator Claw with 2x Servos
Who This Guide Helps
Best for
- Hobbyists building a first robot arm and wanting a pre-configured solution
- Makers who need a reliable claw with known servo specs for Arduino or Raspberry Pi
Not for
- Industrial applications requiring continuous rotation or absolute positioning servos
- Projects needing a custom gripper design with non-standard mounting
