It's just a series of straight lines connected at the ends. It's a good exercise in CAD/PartWorks. Leave a 3/4" border and space the squares about 1" apart - although it rarely works out perfectly. The lines need to be 1.5" apart if you use the recommended 1/2" bit to cut the grid.
Don't shortchange yourself by not trying to draw a grid. I've attached one ready to import into PW you can use for study and your machine.
-B