Eggbot/Spherebot/polargraph Controller

thingiverse

This is a versatile 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. Yes, I know it's 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 love to see the end results! The idea behind this was to create a small, cheap and versatile controller to replace an Arduino Uno and stepper shield (or a breadboard) that 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 updates: 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 it's 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) How I Designed This Designed with KiCad 4.0.x Custom library and footprints included.