hi all,is it possible to design a plane that as no coupling at all ?or am I dreaming

I design an build a plane back in 99 that as no coupling on rudder input,I can do a flat turn with no ail input, kE is the same but i do need to had a tad of down elev in KE.correct me if im wrong but my plane is nose heavy so i need to dial in some up trim to aquire staight flight.so if i would had some tail weight so that the plane fly's straight with a neutral elevator I would probably have no elevator coupling in KE.Am I right?
im gonna post a pic that i took last weekend so u can have a look at my design.its not really hi res pic tho.
jeang