Have you ever heard of a Duplicutter from NWSL? Kinda limited in size for our scale of building, but it takes the guess work out of pieces that fit in it'd dimensions. Or study it's design and make one big enough for your needs. Dan
http://www.nscale.net/forums/showthr...Duplicutter-II!
http://www.ebay.com/sch/i.html?_odkw...at=0&_from=R40