Still countersinking the main spar, I had to modify my little jig to drill the holes for the nutplates not parallel to the edge.



Then I fabricated the spacers which will be part of the tie-down assembly. They got cut from some aluminium bar and then you just have to drill the 1" hole.



Then you have to drill the second part of the assembly. On the picture, the part is positionned above the spacers and then on the spar. First you drill the one hole on the top right, this allows you to slip in a bolt to position the assembly. Then the other holes get backdrilled.
This did not work as planned, the first hole is slightly misplaced to the left and my assembly slipped a little bit, so I have some edge distance issue with the bottom left hole. I don't think is an issue because there will be a nutplate there but the part is only 4,16$ and I already have an order to be delivered soon. There still a lot do do, missing this part won't hamper my progress.