Introduction: Sphere-o-bot: a Friendly Art Robot

About: We love robots, DIY and funny science. JJROBOTS aims to bringing Open robotic projects closer to the people by providing hardware, good documentation, building instructions+code, "how it works" info …

The Sphere-O-bot is a friendly art robot that can draw on spherical or egg-shaped objects from the size of a ping pong ball to a large duck egg (4-9 cm).

The robot is based on the cool original design of Evil Mad Scientist

If you have a 3D Printer and get the ancillary elements (basic hardware + Arduino), you can create this ART robot

Step 1: A Little Bit About This Robot

The Sphere-O-Bot is a simple 2 axis drawing machine that can draw on most spherical surfaces. You can use it to decorate balls or eggs.

This design also features the regular JJrobots electronics (the same we have used in all of our robots). So you can create this robot or any other just simply printing new 3D parts and uploading the appropriate code. Create a B-robot EVO or an iBoardbot after your Sphere-o-bot!

The Sphere-O-bot is adjustable, and is designed to draw on all kinds of things that are normally “impossible” to print on. Not just eggs but ping pong balls, Christmas ornaments, light bulbs, and (yes) eggs (duck, goose, hens…).

The original idea belongs to Evil Mad Scientist. The Sphere-O-bot frame was designed by Attila Nagy and modified by JJrobots. The pen and egg motors are high-torque precision stepping motors, and the pen lift mechanism is a quiet and reliable servo (SG90) motor.

Step 2: How to Create Your Sphere-o-bot?

First. Getting everything you need.

All the elements are available almost everywhere, but if you want to save time and some... "compatibility issues" (you, as a Maker, know what I mean, we are Makers too), you can get everything from here: the official jjRobots KIT! :-) (actually, getting everything from us will encourage us to keep creating OPEN SOURCE robots)

You already have the stepper motors, servo...etc etc but just need the control board? follow this link to get the DEVIA control board


Follow this diagram as a reference. It is quite straightforward to connect everything. But always, check the polarities twice!

Step 4: Lets Start!

This sphere bot has a painting arm (the structure holding the pen) drove by a stepper motor (the DRAWING stepper motor from now on). Another stepper motor is in charge of rotating the object to be painted (egg, sphere…). To keep the object in place we will use two suction cups: one attached to the EGG stepper motor, and the other on the other end. A small spring will push one suction cup into, in this case, an egg helping to hold it tight as we are painting on its surface. Because we will need to raise the pen as we are drawing on the surface, a SG90 servo will be used for this purpose.

If you have doubts, refer to the constantly updated assembly guide here

1. Fix the servo to the piece indicated in the image above. Use two servo´s screws to attach it to the 3D printed drawing arm.

Step 5: Drawing Arm

Put a M3 nut inside the hole prepared for it and screw one 16mm M3 bolt in it. Do the same for the Egg holder (right side of the image above). The hinge for this drawing ARM has been created using 2x 16mm M3 bolts. This hinge should be free to rotate after screwing these two bolts.

Step 6: Suction Cups

Push one of the suction cups inside the D shaped hole of the EGG SUPPORT as indicated

Step 7: Fixing the Stepper Motors and Assembling the X Axis Rod

Fix both stepper motors to the MAIN FRAME using 8x 16mm M3 bolts. Quite straightforward

Step 8: X Axis!

the assembly diagram of the X axis threaded rod (80-90 mm long, M3). Place all the elements as is shown in the image above. The correct order:

  1. Suction cup
  2. M3 nut
  3. 3D printed TOP piece
  4. Spring
  5. 623 bearing (it has to be embedded into the LEFT CAP)
  6. LEFT CAP piece
  8. RIGHT CAP piece
  9. Tiny separator RING (3D printed part)
  10. WINGNUT (M3)

Step 9: Placing Everything in the Right Place

Push the assembled DRAWING ARM into the DRAWING Stepper motor´s axis. Be gentle but push it firmly.

Fit the LEFT EGG support into the EGG Stepper motor´s axis

Double check, paying attention to the diagram above, that you have set everything fine. The pen and the egg are used in this photo as a reference (you do not need to place them now).

NOTE: The servo´s ARM will need some adjustments. This arms is in charge of lifting the DRAWING ARM as the robot paint. You will need to re-set its angle during the calibration process (It´s easy)

Step 10: Electronics + Cables. How to Connect Everything

Fix the electronics to the back side of the Sphere-O-bot MAIN FRAME using M3 6mm bolts (2 are enough).

Connect the cables as indicated. Check the polarities TWICE!


Program the DEVIA Control board using the ARDUINO IDE (v 1.8.1) software. It is quite simple:

1) Download the ARDUINO IDE (v 1.8.1 or above) here: and install it.

2) Run the software. Select the Arduino/ Genuino ZERO (native USB port) board and the right COM PORT in the menu "tools->board"...

3)Open and Upload the Sphere-O-Bot code. CLICK HERE TO DOWNLOAD IT (decompress all the files inside the same folder, name it "Ejjduino_M0")

Step 12: Yes! Your Sphere-o-bot Is Ready to Create Art!

Here you can find some designs. Feel free to download them and send us yours :-)

But, there is still one thing to do...



Download and install the Inkscape software (we recommend the stable version 0.91)

EggBot Control Extension(version 2.4.0 recommended as it has been fully tested)

Download and install the EggBot Control Extension

The EggBot Control extension for Inkscape is the tool that you will use to help you test and align the EggBot, as well as transfer your drawings to an egg. First you'll need to start Inkscape. Once Inkscape is running, you'll have an Extensions menu, and on that menu will be a submenu labeled Eggbot. If you do not see an Eggbot submenu, you have not yet correctly installed the extensions; please back up and carefully follow the instructions for installing the extensions. (LINK TO THE RECOMMENDED VERSION HERE)

In the Eggbot submenu are several different extensions that perform various Eggbot-related tasks. By far the most important of these is theEggbot Control... extension, which is the program that actually communicates with the Eggbot.



Step 14: Done!

Follow us on twitter to know updates of this robot and new OPEN SOURCE robots releases!

Step 15: Other OPEN SOURCE Robots Created Using the Same Electronics + Ancillary Elements


The iBoardbot is a robot connected to the internet capable of writing texts and drawing with great precision. Also, it can erase in a quick and effective way. Send to your iBoardbot your information from any part of the world. As it has a multi-user interface you can also play and challenge your kids, use it as a collaborative notice board or as a twitter wall in your shop window.

B-robot EVO 2:

The fastest self balancing robot (remotely controlled using your own smartphone). Take a look to its skills! Control APP freely available in Google Play

Air Hockey Robot!:

A challenging robot, perfect to have fun and learn robotics at the same time. Your smartphone will become an augmented reality device, showing predicted trajectories and position of all the objects involved in this game.

Control APP freely available in Google Play

Build a Tool Contest 2017

Participated in the
Build a Tool Contest 2017

Microcontroller Contest 2017

Participated in the
Microcontroller Contest 2017