Micro Gripper Kit with Position Feedback Servo

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Pololu item #: 3551
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant


This small gripper uses a rack and pinion design with a servo-driven pinion and opposing racks to keep the gripper paddles synchronized and parallel to each other throughout its 32 mm range of motion. It includes a special micro servo with an additional wire that gives access to its feedback potentiometer, so you can track the actual position of the gripper paddles. This product is a kit, and assembly is required.

This same gripper is included as part of the Robot Arm Kit for Romi.

Compare all products in Robot Kits without Soldering or Servos.

Pictures

Fully assembled Micro Gripper with Position Feedback Servo.

Side view of an assembled Micro Gripper.

Contents of the Micro Gripper Kit with Position Feedback Servo.

Top view of an assembled Micro Gripper (fully open).

Top view of an assembled Micro Gripper (fully closed).

Front view of an assembled Micro Gripper (fully open).

Front view of an assembled Micro Gripper (fully closed).

Opening and closing the micro gripper.

Dimension diagram of the Micro Gripper with Position Feedback Servo. Units are mm over [inches].




Overview

This small gripper uses a rack and pinion design with a servo-driven pinion and opposing racks to keep the gripper paddles synchronized and parallel to each other throughout its 32 mm range of motion. It includes a special micro servo with an additional wire that gives access to its feedback potentiometer, so you can track the actual position of the gripper paddles. This is the same gripper used in the Robot Arm Kit for Romi, and assembly instructions can be found in the Robot Arm Kit for Romi User’s Guide. Please note that the full range of the Micro Gripper requires servo control pulses between 0.5 ms (fully open) and 2.4 ms (fully closed), which is well beyond the standard hobby servo range 1 ms to 2 ms, so you should make sure your control electronics are capable of generating such signals if you care about getting the full range. Due to unit-to-unit variations in the servos, you might need to adjust these values for your particular gripper.

The servo is intended to be powered from 4.8 V to 6 V (nominal) battery packs or a suitable power supply in that general range, and it has a stall current of around 800 mA at 6 V. The feedback voltage ranges linearly from around 0.5 V (fully open) to 2.2 V (fully closed), meaning that there is an approximately 1:1 correspondence between servo position in microseconds and the feedback voltage in millivolts.

Dimensions of the Micro Gripper with Position Feedback Servo

This diagram is also available as a downloadable PDF (318k pdf).

Kit contents

Dimensions

Weight: 30 g

General specifications

Color: black
Lead length: 38 cm

Documentation and other information

File downloads

Frequently-asked questions

What are the wires coming out of my servo?

Most standard radio control (RC) servos have three wires, each a different color. Usually, they are either black, red, and white, or they are brown, red, and orange/yellow:

  • brown or black = ground (GND, battery negative terminal)
  • red = servo power (Vservo, battery positive terminal)
  • orange, yellow, white, or blue = servo control signal line

Please check the specs for your servo to determine the proper power supply voltage, and please take care to plug the servo into your device in the proper orientation (plugging it in backwards could break the servo or your device).

Note: Some of the servos we carry also have an optional fourth green wire that is separate from the three standard ones. This wire provides access to the feedback potentiometer, allowing you to directly measure the position of the output. The servos with this extra wire have "with Position Feedback" at the ends of their product names. The picture below is an example of such a servo.

FEETECH Sub-Micro Servo FS0403-FB with Position Feedback.

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