The bar of 7075 aluminum shown in the picture was enough to make the all of the empenage hinges. The aileron hinges are made from angle and will not be shown on this page. The plans state that either an extrusion or angle can be used for the elevator/rudder hinges. I like the idea of having a more rigid one piece structure than two pieces of angle side by side making a hinge. Yes, the extrsusion is stronger due to it's grain orientation but this homebrewed version ought to slide!
A ball nose end mill made the radius possible in the trough and sides of the double "T". To provide more bearing area for the hinge bolt I made the fingers 1/4" thick but kept the base at 1/8". A layout was done and perfectly aligned bolt holes in the base and sides were made. I left some sides on to make for easier bandsaw cutting. The part will be hand fed into my little Sears bandsaw with the flat (layed out) side facing up. Scribe lines will be polished away afterwards.
The advantages of these hinges over other methods are...
Thicker bearing areas where needed.
Perfectly aligned holes
Hinge pin height uniform when done on a milling machine.
More generous radius at base of hinge.
