The first step in Fusion360 is to create a single sketch for the entire profile of the jig. I like using one sketch because it helps me to visualize the overall form of the object.



Start with the hexagon, using the polygon tool and set the distance between flats at 0.77". This is slightly oversized, and if the jig works well, I'll come back and make some aluminum inserts using 3/4" hex stock. I added a center hole 0.645" oversized to accept a 5/8" shank on the inserts.



The cylinders on either end are 0.40" in diameter and spaced 1.25" from the center. These dimensions are setup for the jig to accommodate stock up to 2 inches thick.

Once you're happy with the overall shape, exit the sketch and move on to creating the solid body.