Single Servo Robotic Gripper




About: My name is Zach Sousa and I'm a Canadian highschool student that has a passion for making.

In this instructable I will show you step by step how to make a robotic gripper. You may be wondering: What does it do? It is basically a robotic hand that slowly closes and if something touches the switch while it is closing it stops so it grips onto the object that presses the switch.

This instructable was originally going to be a celebration instructable for achieving 50 000 views overall 50 followers and 25 instructables but now I am almost at 75 000 views! Thank you everyone that is following me and everyone that views my instructables!

Update: Adafruit has posted this instructable in their blog:

If you like this instructable then you should check out this one:

Step 1: Parts and Tools

Here are the parts and tools you will need to make this project:


Normally closed/ Normally open limit switch

Micro servo



USB A to B cable


3d printer

Filament any colour PLA or ABS

Computer with Arduino IDE

Step 2: 3d Print Files

3d print this file:

Any colour will do but I chose black PLA.

Step 3: Assemble

First glue the servo onto the base piece. Then Assemble the parts together by gluing one of the "fingers" to the base piece as shown in the first image. Then slip the second "finger" onto the servo horn as shown in the second image.

Step 4: Wire Servo

Wire the servo's negative wire (brown) to the arduino's ground. Then wire the poitive wire (red) to the arduino's 5v pin.

Step 5: Mount Limit Switch

Glue the limit switch to the "finger" that is mounted to the base and not the servo. Make sure that when the grippers are together the switch is clicked. Wire the servo's data wire between the switch so that the limit switch so it is normally closed. Then wire the other pin of the switch to pin 9.

Step 6: Upload Code

Upload the code to the arduino.

Step 7: Test

Test and see if it works. The gripper should open and close slowly. If it does place something into the gripper like a pencil and it should stay put. If you take out the pencil it should continue to open and close.

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    7 Discussions


    2 years ago

    Does the brand of servo matter ?


    4 years ago on Introduction

    Hello! I like your design. Can you give me a link to the limit switch you used? I am interested in building one, but I can't figure out what to buy. Googling "Normally closed/ Normally open limit switch" doesn't seem to help and your photo is a bit fuzzy! Thanks so very much!

    1 reply
    Zach Sousazackboston1

    Reply 4 years ago

    Hello, You can use a switch like this one from radioshack:
    If you can't buy this one you can just Google "limit switch"
    Hope this helps!