Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

Three Finger Gripper

by 4ndreas Feb 1, 2015
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Impressive work, thank you for making it open-source to the world!

hello, i am building arm with stepper motors. how to control these geared DC motors ?

hey do u have the stl for the attachment mount pls

hey do u have the stl for the attachment mount pls

do u the the attachment for the 3 finger gripper

when is the Mantis is finished thanks that is the white one right

how do i control this pls u pave a code for it pls

This is the coolest thing I have ever printed! Thanks!

Absolutely excellent. I want to add a finger gripper to my SCARA robot arm project.

awesome design, just ordered the motors! I managed to get some 120rpm 16mm, assume you are using the 6v ones?

Comments deleted.

is the Mantis the ver 4 on wheel or just the arm when u think its finished

Thank you

Mantis is an improved version 4.
The wheels are optional and a later project. Depends on my free time.


where do i get the stl file for the arm in pic thank you
email i900032@gmail.com

Hi, the orange robot arm is quite a mess, I only have the Autodesk Inventor files online:
I suggest you take a look at the green version or wait until the Mantis is finished.

Mantis Gripper
by 4ndreas


Awesome gripper! I'm building this for our student club's drink robot which is Adept's industrial robot arm :)

One question:

I will connect the gripper's motors to Arduino or Raspberry Pi. I want to pick and place one litre bottles which are differently shaped. How can Arduino/RasPi have feedback that now the gripper has a firm grip and the motors should be stopped so that they don't burn. Should I try to monitor the current the motors take, place force sensors somewhere, or something? Thank you!

Hello Andreas,

first thanks for this great project :)
Currently I have all parts printed and I started to assembly but I wait for motors delivery.
I have two questions:

  • Can you give us the springs parameters?
  • Can you upload last two parts?

Thank you in advance.

I think the springs are 5x20mm or something like that I bought a 5€ 200 piece pack with springs and just used what fees good ;)
the gear for the servo didn't worked as I planed. Now I use the normal servo hinge and a wire. I still don't have a better solution.

Hi 4ndreas!

I've already all the fingers printed but I think it's missing the pinion of the Servo. Thanks so much. Incredible Design!

Do you have a link to the motors you bought (:

Printing now...

I bought the motors over ebay or aliexpress, the are labled as "3mm Shaft 16mm Diameter DC Geared Motor 12V 120RPM w Gearbox" Just compare them with the drawing I included in the pictures.

Is this is the same motor ? "ZnDiy -BRY 16GA-120 DC 12V 120RPM Geared Motor"

I bought motors from your link and they fit perfectly.