I haven't built my machine yet, I'm still working on getting everything together.I will probably start with 48x48 inches in structural aluminum.
I hope to have some new servos in 1 week and a day
(wink,wink) if the subscription gods are looking favorably upon me
I think Hu's answer came closest to the question I was asking. I have past experience with cnc machines but none with hobby cnc's and I haven't seen anybody address these questions in the forums. Thanks for all the great answers, I'm taking notes!
Don
On a side note, I found a guy who says he has about 1000 feet of structural alum., (45X45) that he wants to part with. I will post it in the For Sale forum in a couple of days if it works out.