Dimpling Flap / aileron spars for nutplates

[haribole]

I am getting ready to attach the hinges to the flap and ailerons and got stuck on how to dimple the spars to fix the nutplates. The backing plate on the spar are so thick and also, the nutplates I got do not have any dimples on the ears.

Has any one have advice on how to proceed?

Thanks
Hari

[John Rheney]

Hari,

I countersunk the spars for the nutplate rivets instead of dimpling. I also used one-legged nutplates so I could move the rivets away from the sides of the hinge pockets to make countersinking and riveting easier (more access.) Doing this, you don't need countersunk nutplates either.

Hope this gives you some ideas.

John