Introduction: LittleArm V3 Arduino Robot Arm

About: At LittleBots we are creating 3D Printed Robot Kits that get Kids excited about robotics and STEM

We want to build STEM kits that get kids excited about technology. So far we have created and launched nearly 10 kits. And now we want to improve our original Arduino Robot Arm again.

In 2016, a guy in a garage built a small robot arm using an Arduino Uno and his 3D printer. After tons of people asked him to turn it into a kit, Slant Concepts put it on Kickstarter. It was funded in under a week and hit more than 260% of its goal by the end.

With the great response we took all of that feedback created a simplified and rugged version of the arm called the LittleArm 2C. It ended up raising 560% of its original goal.

Now, Nearly 3 years later, we are launching the third generation of Arduino Robot Arm. The LittleArm V3. We have again taken all of the feedback from hobbyists and classrooms all over the world to further simplify the kit. The LittleArm V3 We have stayed true to our principles and have made the V3 simpler and more reliable to build and use. So that classrooms can continue to have a great robot arm to implement into their curriculum.

Whats the "V3"

The V3 is the third version of the LittleArm that we have made. It has fewer parts and relies more on 3D Printing than any of our previous kits have. The LittleArm Original was the very first kit that we ever created in 2016. Then we followed that in 2017 with the LittleArm 2C. And it took quite a while to find a way to improve on that on. But we found it.

  • Gripper - We have turned 8 pieces into 1. This gripper eliminates complexity that made it difficult for younger kids to work with the kits. It is also able to grab more stuff.
  • Overall Design - Sleeker with even fewer screws and complications. Every piece has been optimized.
  • Improved App and Demos - We have updated the software for the arm and will be releasing new demos.

Overall, we figured out how to further optimize all of the parts to make easier to put together. the gripper that was once 8 pieces is now just 1 piece. Only 2 of the 4 servos need a screw, so kids don't lose those tiny set screws in the rug. And we have made it even tougher so it can take the abuse of classrooms and groups better than ever.


  • 3D Printer
  • Arduino Nano
  • Metal Geared Micro-Servos

Step 1: ​Mechanical Design Upgrades

The LittleArm V3 is the third generation of the LittleArm. And you can tell.

Faster 3D Printing

The LittleArms were the first really viable 3D printed robot arms. But with the V3 we have improved on that. We have reduced the 3D printed part count to just 4 pieces. They can fit on basically any machine and they can be printed at the lowest resolution (0.3mm) in PLA and come out looking great.

Further Optimized Shoulder

The Shoulder from the Original to the 2C was a big leap. But we have gone a step further. Streamlining the should and allowing it to clamp onto the servo. This means we no longer have to use screws for the Servo horns.

New Gripper

When having younger kids build the LittleArms there was always one part that was difficult. The gripper. It had 4 small screws that had to be put in just right and it was often challenging. We wanted to eliminate all of it. But it took a long time and a lot of experiments to create the new V3 gripper.

The new gripper is all one 3D Printed part. The designed spring in one finger eliminates all of the screws but still gives it a full range of motion. All of that complex assembly is eliminated with a really cool design feature that other people can use and learn from.

The New gripper is also able to grab more stuff. The wider fingers let it pick up fabric and also allow us to cut out sections of the claw so that it grab horizontal objects, like a pencil, that were impossible for the original LittleArms

Only 21 Parts (counting screws)

The LittleArm has the fewest number of parts of any other robot arm kit. to put it together it is basically just snap-and-go the screws just make sure it doesn't fly apart.

The LittleArm 2C held the record previously with 31 screws. We basically cut that in half. And any other arduino robot arm you can find will have about 100 pieces in total to be lost as soon as you open the box.