This is a dual stepper motor controller board that takes two stepstick style stepper modules (DRV8825 or a4988 or similar) and an Arduino Nano.
See http://www.thingiverse.com/thing:1393222 for a PCB mount.
It can be used as the controller for a polargraph or Eggbot/Spherebot or some other drawing machine with the appropriate firmware loaded onto the Arduino Nano.
Yeah, I know, not really printable, but if you have a CNC router or a router setup on your 3d printer, you might be able to make this. If you do, i'd really like to see the end results!
The idea behind this was to make a small, cheap and versatile controller to replace an Arduino Uno and stepper shield (or a bread board) and could be used on more than one drawing robot. With Arduino Nano clones and stepper driver modules available on ebay for less than £2 each, and excellent low cost PCB prototyping services like iTead Studios, it should be possible to build this for ~ £10 each. Note: The other components came from Tayda Electronics. I wasn't able to find 15 way female headers (that were cheap) for the Nano, so I use 16 way and cut off one of the pins.
As this is using an Arduino Nano, the polargraph firmware is 'feature light'. If you want the full fat version with the awesome Norwegian pixel rendering, check out euphy's stand-alone Polargraph controller and kits http://polargraph.bigcartel.com/
PCB files are in the zip. Ignore the .sch file, I had to include that so thingiverse would let me save this thing...
The PCB has been on github for a while now and that is where changes generally go first, so it might be worth checking that for changes: https://github.com/MarkJB/Eggbot-Spherebot-polargraph-Controller . Also the readme has a Bill of Materials and some pointers on assembly (I haven't bothered with instructions as its pretty simple).
I've modified the polargraph & Spherebot/Eggbot firmware to work with the v2.2 board (the files here are v2.2 but the photo of the PCB is of a v2.1 board).
Polargraph firmware: https://github.com/MarkJB/polargraph_server_a1
Spherebot/Eggbot firmware: https://github.com/MarkJB/SphereBot
Thanks to the work of a member of MakeBmth (our local Maker group) there is also a port of the Gocupi firmware (a Python port/re-write of the control software called Pycupi: https://github.com/brianinnes/pycupi)
Designed with KiCad 4.0.x
Custom library and footprints included.