Thanks Barry,

A short list might include:
The tool deflection in Z due to gantry / gantry rails flex
Tool deflection in the other axis when cutting
Maximum jog speed due to ballscrew whip
Motor power requirements
You are thinking along the exact same line as I am, A few Machine specs on one or two pages that then automatically enter on to the subsiquent calc sheets like your ganrty siffness one (no point in reinventing the wheel). Like you said its how far you go?? I had planned to just evolve it over time.

If I can help, and have the time, I'm here.
Perfect I was hoping you would say that, Thanks. Ive just about got my head around excel side on it now with the conditional formating. Its a pain to learn but quite a good program.