Another variant on MakersBox Arduino Drawing Bot. Both the Pro Trinket from Adafruit and my DIY arduino solution work fine with 6V so I thought it would be a perfect opportunity to try to incorporate my battery packs (http://www.thingiverse.com/thing:1096639)
I used the original battery pack design versus the newer slimmer model because the larger space puts less stress on the printed plastic and I had the space under the bot to use them.
I soldered the leads to make the 6V pack but only because I was testing soldering to stainless steel. Pressure fit 22 gauge jumpers will work just fine for a solderless build.
The result is a smaller bot than my previous model (http://www.thingiverse.com/thing:1287264) with the same functionality. However, thinking past the drawing aspect, a smaller robot may make it through a maze a bit easier...
Both work great, and the credit should be given to MakersBox for a great design.
Recommend using countersunk M3 screws to mount the ball caster in order to give you a flat area onto which you can position your breadboard with dual-sided tape.