Now it's time for the elevator trim! This is a bit harder than the aileron trim because we have to attach a back-plate to each rivet position!

OK, much like with the aileron trim, we fasten the hinge to the tab (carbon fiber instead of aluminum in this case) and drill the holes through both at the same time so they all line up perfectly on both pieces.

...and the line-up on the elevator itself...

And now we have all the holes in all the right places on the trim tab and the hinge both:

So here is our hinge with the holes drilled in it. (removed from the trim tab of course)

Now we put a countersink bit on the power drill to counter-sink the holes... this will shape them properly to accept their rivets.

And here is the hinge after the counter-sinking on the center-left. See how the holes on the center-left have the perfect bevel? That is what lets them hold the rivets.

We use the temporary bolt in my higher hand to hold the backplate in place...

Now drop a little back-plate into the hole with a temporary bolt as a guide.

And then drill through the two little holes that secure the back-plate to the hinge.

And then drop the rivets into those holes! See how the 2 little rivets go into the two little ends of the backplate there? Then, later, we will be able to screw this hunge line to... anything!

Then start to squeeze the rivet...

And finish squeezing it... the backplate is now locked in place, so you can screw it onto anything by running screws through the backplate.

See? One is done! (on the top)

And attach the next...

Then two are done!

And, eventually, all!