So I finally got my Folger Tech 2020 I3 assembled. An issue that I came across is that when I Home the system and it finishes homing the Z axis emits a loud whine. This also happens for any axis after it finishes moving to a position although the Z axis is the loudest/highest tone. The sounds eventually stop but sometimes they only stop after turning it off or pressing E-stop in Repetier. After looking around people seem to say it is over/under voltage to the motors. If that is the case how do I properly adjust it so the motors get the "right" voltage?

Extreme beginner questions, how do you load the extruder...., is it as simple as heating the extruder and pushing it in and doing a manual feed that being said how do you manual feed the extruder?

Thanks for putting up with my questions!

Adjusting the Vref is described here.