Tip: Drilling tank attach angles

[DragonflyAero]

I dreaded measuring and marking both flanges of each tank attach angle to find the "exact" center so. came up with a simple jig that I clamped to my drill press. I simply cut a couple of pieces of scrap angle to about 3" and then drilled and clecoed them to a 2x4 where the attach angle would fit exactly inside them. Then I measured and marked one flange, placed it on the jig and then clamped the jig to the drill press so the drill was exactly centered on the mark. This made quick work of drilling all of the center holes in the angle flanges.

 

[DragonflyAero]

Thanks Jon!!! Also, I found that my back rivet plate was almost exactly the right thickness to draw the lateral center line, and was certainly close enough to provide a visual reference when aligning to the spar. So I just placed the angle against the edge of the plate and drew a line with the Sharpie.