I completed the fin and rudder of the vertical tail, including hinging, this morning.  The first picture below shows the vertical tail.  Again as with the elevator, I added gussets to the T.E. ribs of the rudder to better support the T.E.  The spruce insert on the forward edge of the rudder will be drilled and tapped with 2-56 threads for mounting the nylon control horn on the right side.

The second picture was taken to show the "foot print of the fin that screws to the top of the stab with nylon screws.  You see the two 2-56 threaded holes from the bottom, which is lined with thin 1/64" plywood.  In addition, if you look close, you can see the rudder's small nylon hinges pinned with a continuos .031" wire, which is removable.  After the tail has been mounted to the fuselage and the control horn has been positioned on the rudder, a bottom hinge will be installed and pinned separately to the aft end of the fuselage for a three hinge rudder support.

The third picture just shows the fin mounted to the top of the stab with the rudder and elevator pinned in place.  I have to hand it to Jim O'Reilly's structural design, this makes a really great tail group.

At this point, I will take a short break for a day or so.  I would like to test fly my new Class A Bomber, if this rain will ever stop.  My next door neighbor has some time off and has agreed to go an crew for me when I test fly the Bomber so I finally have some help me.  Then I will get back to the Airborn and install the radio, hook up the throttle linkage, and install the push rods so I can properly locate the control horns.  More later..........

Picture 3  This shows the top of the stab with the plywood clamping plates and nuts.  The four 4-40 nylon AHCS, seen protruding through the top of the threaded plastic inserts in the stab, will later be cut off to a length that is just below the surface to so as to not interfere with the stab's top covering material.

Picture 4  This shows the fuselage upside down, resting on two milled pine blocks, and weighted down  with a steel cornering block.  This insures the lateral plane of the wing platform is parallel with the surface of the work table.  In this configuration, the height of right and left tips of the stab rear spar from surface of the work table can be measured with a carpenter's square as shown in the picture.
NOTE: There was an 1/8" difference in the first measurement.  So the the jigging was disassembled, and the stab removed.  The two top longerons were carefully and lightly sanded in the stab mounting area, with masking tape placed on the low longeron.  The stab was reinstalled with the jigging and the tips remeasured.  It actually took two passes to get the two tip measurements equal.  Patience's, lots of patience's!

I came up with what I think is a great approach for aligning the stab on the fuselage to glue the two stab mounting plates in place.  The pictures and descriptions are as follows:
Picture 1  This shows (1) the bottom of the stab, (2) the two 1/16" plywood stab mounting plates, (3) the four 4-40 nylon "Allen Head cap screws" (AHCS) and nylon washers, and (4) the fore and aft jigging fixtures consisting of 2-56 all thread rods, nuts, plywood clamping plates, and a balsa wedge for the front jig.
Picture 2  This picture shows a couple of things.  First, the two 1/16" plywood mounting plates screwed to the stab with the four 4-40 nylon AHCS and washers.  Second, the fore and aft clamping jigs have their 2-56 all thread rods inserted through the holes in the stab plate (S4) that are used to screw the fin to the stab and made up using the plywood clamping plates and nuts.  Notice the balsa wedge is used on bottom of the forward jig to compensate for the slope of the bottom longerons so that clamping is done squarely.


Picture 4 & 5  Once the stab was aligned laterally, then measurements were made to check the stab's longitudinal alignment. These two picture shows two views of the fuselage right side up resting on the two milled pine blocks and weighted down with a steel cornering block.  A yard stick is used to measure from the fuselage second vertical truss member at the front of the cabin diagonally back to each tip of the stab's rear spar.  Longitudinal alignment is achieved as follows:  (1) Align the stab's rear spar centerline with the center joint of aft fuselage. (2) Measure the distance back to each tip.  (3) Loosen the forward jig nut slightly and carefully rotate the stab (just a very small amount), retighten the forward jig nut, and remeasure.

Once the stab is aligned, mark the two 1/16" plywood mounting plates from the bottom.  Disassemble the clamping jigs and remove the stab.  Apply a sparing amount of 45 minute epoxy to the marked areas of the mounting plates.  Reinstall the stab with the jigging, align to the marks on the plate, and recheck the longitudinal alignment measurements.   The 45 minute epoxy was selected in order to provide sufficient amount of time for this last installation and alignment before the epoxy hardens.

Once this has hardened over night, I will remove the jigging and stab and finish the planking of the stab mount, which will be the subject of a later report.