Need to drill 2 holes in the gas tank inboard end ribs. One for the 3/8" BNC connector and one for the 7/16" fuel vent fitting hole. The plans don't really spell out where to put these holes. So, Image 1 shows what I did to locate the holes.
1.) Draw Line 1 tangent to the edges of the raised rib stiffener bump outs.
2.) Measure left 1" from the vertical bump to line 1 to locate line 2, the intersection of line 1 and 2 is the center of the 7/16" diameter feul vent hole.
3.) Measure left,2", as per plans, to the left from the feul vent hole, line 2, to locate line 3.
4.) Measure 3/4" down from the rib flange on line 3 to locate the 3/8" diameter BNC connector hole.
Image 4 are the fuel line vent fittings.
Image 5 shoes the holes and my first actual use of the deburing tool pictured. I used a step drill in my drill press with out drilling a pilot first.