Just another comment, a little off topic but you mentioned dual extruders. We have a Replicator 1XL with dual extruders. It was a cute gimmick in the beginning but we never utilize it anymore! I did a two color job on another one of my son's printers Friday and it doubled the printing time because it had to keep heating up the "other color", print a layer and then go back to the other extruder, heat it up. After 6 hours, the print looked awful, I had printed the same piece in one color last week on the PrintrBot and it came out awesome? Just saying! Two color printing is not for me!