The Taz 3 does not have a dual head extruder available commercially... right now. We will have the dual head extruder at St. Louis, or if you won't be there but want a sample print, just email me at
wwerst@highlandersfrc.com. And as for the build volume, the Taz is massive. Once our bus gets to St. Louis, I will post some pictures of the printer set up in our pit.