ho are you dealing with screw flex and twist, and all the other forms of backlash, with a single loop sevo system? Are you deriving the velocity and acceleration inputs from the position inputs of the scales? I don't think it's a software issue, as much as it is the nature of the beast. with all the possible hardware combinations I think it would be cost prohibitive to design and build a control that handles everything really well in a plug and play fashion. The number one thing the industry does, is buy matched drive and motor sets. They are essentially plug and play, because someone did the toning for you, but they are super expensive and only work well as a matched set.