A customer at the wood working shop at the program for mentally handicapped people where I work asked for a large sign to be made. The sign reguires letters that are 4 inches high but the largest size of letters that letter/sign template kits for routers is 2-1/2". Would this be the first job for the CNC machine that I'm building from plans from Solsylva? I think that I have to route part of the sign, move the machine to another part of the sign, route that part of the sign, and repeat, or make 4-inch high letter templates using my CNC machine and use hand-held router to make the sign. Any suggestions?

What size bed will be on the new router. You may just have to cut your sheet material to suit the router certainly not use the router to make templates to make the letters, at 4" high that shouldnt be any problem whatsoever. Just bang em out!