For all noobs, youre trying to print and your extruder gear is just sitting there sputtering! For the Melzi controller go and set the current at 1 volt, then loosen up your feed tension screws and print until the gear stops sputtering, just tighten the feed screws a little each time until it works.

DO NOT FOLLOW THE ADVICE ABOVE.

Setting your voltage to 1V on a Melzi (v2 board, it's even higher on the v1 board) sets the current to 1.25A, which will make the motor run hot, possibly enough to soften the plastic of the extruder. There is plenty of torque in the motor at the suggested setting of 0.6V to 0.8V. If you're having problems with it feeding at this voltage, look for problems elsewhere, such as partially blocked nozzle, extruder idler tensioning bolts too tight, inconsistent filament.

Ian
RepRapPro Tech Support