Motor control using jrk 21V3

Hello
I am very uninformed on how to configure and use the jrk 21V3 I purchased. My intent is to use the jrk 21V3 to control the position of an axel which I will rotate with a small 12 volt (3 amp) motor. I want to position the axial position of the axel by rotating the shaft of a pot. The purpose of this device is to be able to point an antenna to a moving satellite. I have two axeses and two jrk 21V3 controllers.
Is there anyone who has already fabricated a system similar to what I want, so I can avoid “learning”??
Thanks Jerry