Brief Description: Z brackets - drilling nutplates
I started by just marginally flattening out the rounding on one side of the nutplate. I just wanted to be sure that the nutplate sat flush against tge bracket's flange and wasn't hindered in any way by the web-to-flange rounding. I then put 5 of the thick washers over each of three AN3 bolts and tightened the nutplates to the brackets.
I found that tightening the bolts "finger tight" was more than enough as there was no way I could move the nutplates subsequent to that. Consequently, I bolted the three nutplates onto the bracket, aligned them, tightened the bolst and placed the bracket into a vice. I then proceeded to drill all six rivet holes before removing the bracket from the vice, removing the nutplates and repeating the process again for each subsequent bracket.
Once all nutplates were match drilled to the brackets, I deburred using the Cogsdill Deburrer and a large hand-held drillbit.
One side of each nutplate ground flatter to ensure the bracket web does not prevent it seating well.
Z Bracket with nutplatesbolted to it in the vice ready for match drilling
