After Tested with the new controller then I found that Original KR-400 has the scale which indicated North (0) at the center scale, it will confused the user if the Rotor turn from 0 to 360 Max then I start to modify the scale to match the real position.
SCALE Part :-
For the KR-400 to display 0 - 360 not the 180-0-180 as the original Kenpro designed then It need to scan the original scale and then cut and paste then move around the number of degree to have South as Center of the scale to match 0 volt and full scale as 5V then I used the Paint-Brush program to edit and print the actual size to match the scale plate.
First, I want to use the solid-state relay or the "HEXFET" PVG612PDF from IR to controller AC motor but I checked price per part if I will order from Digikey or Newark around $8-$ +S&H and I will need 4 of them, well cost will be like $34 USD and since this is not the my controller and I build for my HAM Club so then non profit at all and need to be as conservative budget as perfect as I can then I found the many of my 12 V relays laying around my old component box so then I modified the relay board to be used for 2 Transistors which will receive active "LOW' level logic from my Arduino controller and the add 6 Volt 7806 for the POT encoder voltage because of the long cable dropped the voltage below 5V when it fully turn to maximum. All worked up pretty good, Need to do paint job with my Controller box (Powder Coating) . I was thinking about build the nice Kit for other Ham too, let see if I have time left.