Recipe for SphereBota

I wanted to have SphereBota - something like plotter allowing for painting the spherical objects (eggs, balls, baubles).
It was something like this:

The device itself is quite simple, because in contrast to the plotter uses the same rotation, which is easier to obtain than linear.
Because of the upcoming Easter holidays I wanted to created a device as soon as possible.
Not silyl in the manufacture of its electronics only used the not very well-liked by me Arduino platform.

HARDWARE

Due to the fact that I have not found any project which is 100% that could serve (other mount motors, etc.), I decided to draw whole again.
I used openscad programs and QCad. The entire set of files can be found on my thinkiverse.
In addition to the printed parts the following parts were needed:

• thread rod M10 + washers and nuts
• thread rod M3, bolts M3 + washers and nuts
• 2x bearings 6000
• RC servo
• arduino UNO
• 2x stepstick
• 2x step motor
• spring (I got one from desoldering pump)
• piece of rubber
• marker pen

ELECTRONICS

Time was important to me, so i try to adopt model on http://pleasantsoftware.com/developer/3d/spherebot/ during the trial, however, I introduced some changes in the project. The final version is shown in the diagram:

In addition, I made a simple single-sided board so that electronics was nicely integrated into the structures of the device. Due to time constraints, I made PCB myself using a thermotransfer method.

FIRMWARE

I used the firmware from:  https://github.com/zaggo/SphereBot
I only modified pinout maping and the parameter DEFAULT_PEN_UP_POSITION
so that when you print finishing servo was kept in the upper position.

To compile the firmware you have to overdub two libraries to arduino:

1. http://playground.arduino.cc/ComponentLib/Servo
2. http://playground.arduino.cc/Code/Timer1

SOFTWARE

I draw the model in vectors in Inkscape.
To generate gcodes I using a plugin to the program: https://github.com/martymcguire/inkscape-unicorn
The generated code sent to your device using the application processing environment:
https://github.com/zaggo/SphereBotSenderProcessing Though really you can use any simple terminal program.

How does it work:

Video from first test below:

Similar construction:

• http://www.thingiverse.com/thing:201052
• http://www.thingiverse.com/thing:20398
• http://www.thingiverse.com/thing:7988
• http://www.thingiverse.com/thing:7656