LB23 is the hardpoint for the landing brake hinge. It needs to be slotted into the fuselage at a 45 degree angle. You may also notice I've routed the brake depression a little deeper to allow for the later inside layup. More on that later.
I first made a jig which was a hole in a bit of wood at a 45 degree angle. I did this in a drill press with an angle vice. Even trial and error would work on a scap piece of wood until the angle worked.
Then I did trial drillings to determine where the hole would go in a piece of foam relative to the front edge of my jig. In other words where do a draw a line of the fuselage bottom to put my jig so the hole is in the right position? I practiced drilling as well on scraps.
Then get the right position drawn for the slot. OK I measured this a few times until I was sure it was in the right spot and would have made a mistake if I hadn't checked several times. It would have been repairable but thats hardly the point.
I drilled the slot with a hole about a .2" along each time having marked all this out and down to the right depth as well. Worked out well.
The last pic shows LB23 half in position (it was hard to get out) and at the required angle.
