BIG Project, What Is the Actual x to x and y to y carving distance

[MartinGutzmer]

Hi Folks,I Am being tasked to do a sign,about 30" square.I have never made anything this big overall, I have done narrower and 13 feet long,but not square.
So, for this BIG Project, What Is the Actual x to x and y to y carving distance safe max dimension?
God BLess,
Martin
Project Link Below.

Church Sign

[MartinW.Mcclary]

I’d measure the space if were me .This is from the net: 800 is just about 31.5".