Quote Originally Posted by AbuMaia View Post
I do find it odd that my experience seems to be the opposite of many others. My servo works just fine plugged into RAMPS, but when I add a 7805 to give it separate 5v, it goes crazy.
Well, the reprap thread you linked to talks about the same thing I've been saying - not all servos are the same. You could basically just be lucky with the servo you have not drawing a lot, or you don't put much of a mechanical load on it, never stall it (ie, servo is not put into a situation where it mechanically can't move), and the MEGA2560 regulator has a chance to cool off in between servo moves.

On the 7805, did you include any capacitors on the input and output pins? If not, that could be part of why it didn't work out. A larger capacitor on the input would help sustain the input voltage to the regulator during current surges, and a smaller capacitor on the output helps keep the regulator stable with the inductance of wiring connected to it. What I remember from reading countless datasheets and application guides over the years is that the input capacitor is generally required if you're more than a couple of inches from the power source, and the output capacitor is generally viewed as always required.