Countersinking AEX Wedge
One challenge I had to figure out is how to machine countersink the rudder trailing edge (R-916 a.k.a the AEX wedge). There is about a 8 degree taper to the trailing edge and looking at web sites of other builders, they machine countersinked the AEX wedge with the countersink running perpendicular to the skin holes. In other words, I need to figure out how to countersink this thing with the sides perfectly flat with the countersink cutter perpendicular. Tami actually came up with the design (jig) to accomplish this.
We started by angle sanding a 1" x 3" wood using a Dremel belt sander that I purchased when Tami was doing wood crafts.
Tami was able to roughly sand the angle into the scrap piece of 1" x 3" wood. When Tami got it roughed in, I took a wood chisel and "fine" chiseled the angle I needed in the 1" x 3" by taking out a sliver or wood, setting the rudder trailing edge in the angle and doing it all over again and again until I got this thing to lay flat in the scrap wood.
As you can see, the rudder trailing edge (R-916) lays flush in the "wood jig". I then clamped it to the drill press and drilled a #40 pilot hole into the wood jig so that the countersink alignment pin cutter had a place to go.
Once I got the countersink properly adjusted to allow the rivets to sit roughly flush, the simple little jig made some really nice countersink holes in the rudder trailing edge. Care had to be taken not to over countersink these holes as the piece is not really all that thick and it is countersunk on both sides so that the rudder's trailing edge will be very thin. Over countersinking would result in enlarging the hole as it would cut completely through the trailing edge piece.