Prusa I3-Extruder keeps skipping

Hello,

I decided to get a 3D printer finally to play around with. I bought a Prusa I3. Using 1.75mm filament, E3D Hotend, upgraded heater bed.

I am having issues getting my extruder, I guess tuned? It keeps skipping. So this causes my printers to be very stringy. I guess it doesnt have enough
torque to push the filament through. I did some reading and the larger stepper motor is suppose to be around .4-.6v. I currently have it at .612v I do believe but it
is still skipping.

Can someone give me some advice on what Im doing wrong here?

Thank you!