Hi, I'm building a cabinet with 1.75" square face frame members and two 8 x 50mm dominoes at each joint oriented to optimize resistance to racking. The mortises at the stile will be 8mm so no wiggle room. The mortises in the rails will be 14mm and I prefer not having the 6mm slop running in the racking direction. The attached rendering (no where near scale) shows how I want to orient the dominoes on the stiles. The challenge is using a dead-on accurate reference for the mortises on the rail that keeps both ends of the stile perfectly square to the rails. Any tricks you could share?
The easy method would be to rotate the dominoes 90 degrees...and maybe I shouldn't be concerned with racking.