birddseedd:
But all of the servo Motors on Amazon seem to be for little plastic robots. I need something big
So just to clarify, you are talking of the ones that look more like steppers in those big nema style casings, not the normal Arduino world rc servo?
(fwiw, adafruit do have the latter with 4 wires, the extra one being a take-off from the internal pot to bring the position out.)