Step 2: Motion. Time for a RAMPS board! After a lot of hunting around I decided on the "Ramps 1.4 Mini Set" from gadgets3d.com. For only $90 it came with RAMPS 1.4 board, 5x G3D stepper drivers, cooling fan, SD card reader, 2x thermistors, and wiring harnesses. Because this is a delta design, 5 stepper drivers gives me 1 for each axis, 1 for the extruder, and a bonus spare for a backup. If I manage to survive without needing the backup, it becomes a 2nd extruder driver. The kit even came with a ceramic screwdriver for stepper driver adjustments.

A standard 9V wall power supply was used to power the Arduino Mega, and a salvaged 12V, 4.6A laptop power supply was stripped and used for the RAMPS board. The firmware is [jcrocholl]'s modified Marlin firmware, on github. For control software I opted for Repetier-Host.

Installed, powered, and apparently running I tried to connect and... cannot. Once the firmware is uploaded to the Mega and the RAMPS board added, the device fails to show up on my computer. I have not had the time yet to troubleshoot this. My hope is that there is an address setting conflict that I can resolve. If there is an issue with the RAMPS board itself it will be much harder to diagnose.