On the inside of the canopy frame there is an attachment angle as well. When I fabricated the angle the plans called for one hole to be predrilled and the other drilled in final assembly. I used the 90 degree drill attachment and drilled the first hole through the frame with a #40 drill. Using that hole for reference I measured and marked the location of the second hole. I drilled that using #40 from the outside of the frame.
Then it was just a slow process of drilling the hole to size. The last image shows the two holes ready for an AN3-5A bolt. Tomorrow I will take everything apart for final paint and then set it all on the shelf. I need the access to finish installing systems. The frame is just about done.