Thanks for your reply, Brandon. so, since i already have the motor/encoder, i just need to buy the "Pololu Jrk 21v3 USB Motor Controller with Feedback (Fully Assembled)" unit, correct? Does it come with software/GUI to program it over req'd serial interface?
do i need anything else, besides the power supply?
thanks again. you have been very responsive and helpful. boy do i need help in this area...i am totally a new-bee. i am a mech engineer, i design mechanical packaging mainly, structural stress analysis, thermal steady-state analysis, etc.