Hello Galaxy.

How to build own R2-D2 with LittleBits Droid Inventor Kit

I have developed the original R2-D2 using the littleBits Droid Inventor Kit.

It has the following functions.

  • Dome rotation
  • Full color LED linked to the voice of R2-D2
  • Walk with servomotor and DC motor
  • Built-in Web API
  • Respond to Google Home's trigger

I will write the development process in this article.

1. Buy Inventor Kit



2. Build.

Build Invnetor Kit. However, because this kit is clear plastic, you can not feel the force as it is.


3. Dismantle and paint

3.1. Paint with white color

I painted it with a spray can. Before painting, do not forget to put a masking tape on the part to be transparent (for example, place to put the LED inside).


3.2. Paint with silver color

Like painting white, I painted it with a spray can. However, I made a mistake the painting process. When masking tape is put on silver paint, gloss also peels off together when peeling off masking tape. Therefore, silver color should be painted at the end. I think that the painting process should be done in order of white, blue and silver.


3.3. Paint with blue color

Finally paint blue. As I wrote in 3.2, I mistook the order of painting, so I could not paste the masking tape. Therefore, I painted it with a pen. (If you paint with a pen, there is no need to paste a masking tape)

f:id:GALACTIC1969:20180126004011j:plain f:id:GALACTIC1969:20180126004018j:plain f:id:GALACTIC1969:20180126004030j:plain

3.4. Sumiire

After painting White, Silver, Blue, I will do Sumiire. Sumiire is the work of tracing the edge with a thin black pen along the recessed part of the body.


Three-dimensional feeling will be increased by doing this work.

Before Sumiire f:id:GALACTIC1969:20180126004037j:plain

After Sumiire f:id:GALACTIC1969:20180126004105j:plain

3.5. Topcoating

When all painting is finished, lastly the top coat protects the painted surface.


4. Enhancement

Because this kit contains only the minimum parts, I extended the function. I installed a motor and full color LED and Raspberry Pi which controls them. This kit contains mounter (plate full of holes), and there is more space inside the R2-D2, so it is very easy for the user to expand the function.

4.1. Dome Rotation with Stepping Motor

I use stepping motor to rotate dome.
The product name of stepping motor is MDP-35A.


Also, in order to connect the stepping motor to the R2-D2 dome, I printed the shaft with a 3D printer.



When the body and the dome are in contact with each other, the friction is large, so it was not possible to turn the dome with the torque of MDP-35A. So, the rubber is wrapped around the shaft so that the body and the dome have a little space.

4.2. Full color LED linked to the voice of R2-D2

I put a full color LED so that the mouth of R2-D2 glows. The LED flashes in link with the voice of R2-D2.

4.3. Device control and Web API implementation by Raspberry Pi

little Bits, stepping motor, full color LED, all devices can be operated from Raspberry Pi. In addition, it can be operated from the outside through Web API implemented on Raspberry Pi. I also link this R2-D2 with Google Home.

f:id:GALACTIC1969:20180126004231j:plain f:id:GALACTIC1969:20180126004218j:plain

5. Summary

I have developed the original R2 - D2 using the littleBits Droid Inventor Kit.

It has the following functions.

  • Dome rotation
  • Full color LED linked to the voice of R2-D2
  • Walk with servomotor and DC motor
  • Built-in Web API
  • Respond to Google Home's trigger

I prepared the following parts additionally.

It took a lot of time to make up, but I am very satisfied with the finished product. LittleBits Droid Inventor Kit is the best kit to make your own R2-D2.

  • Affordable price
  • A mounter is included, and there is space in the inside of the body so you can pack parts
  • It is strongly made because it is an educational toy

It was better if there was a Node.js SDK for the BLE module. Reverse engineering of the BLE module was very difficult.

And recently I bought Matrix LED at Amazon. Now I am trying to implement this on R2-D2.