Great work on the suitcase 3D printer!
I've learned about a new style of DIY 3D printer called the "Rostock" Delta bot by Johann Rocholl. It uses 3 arms to move the nozzle head around instead of 3 defined axes. It's a wonderful looking machine that solves a lot of the issues with the other models.
Here are Johann's sites-
http://www.thingiverse.com/thing:17175
I think you can make it with
1. Smaller volume but with bigger build area than the briefcase printer.
2. Travel friendly.
3. Dual extruder compatible (maybe even triple extruder) it uses remote extruders on Bowden cables...
4. Filament spool management built in.
5, Stand alone printing.
6. Really Awesome!
7. Open Source!
8. Partially self replicating (Reprap Project)
