It was a productive and satisfying weekend at DOG Aviation as the eagle grew another tail feather … the stabilator, which is the final and largest tail feather on the bird and required a good amount of riveting.
Digressing for a moment, while helping my friend
Pete with the riveting of his RV-9A we both enjoyed the rat-a-tat-tat sound a
rivet gun makes while pounding rivets into a bucking bar, it was the sound of
progress … the sound of an aluminum airframe taking shape. I miss the sounds of nicely pounded rivets,
but am beginning to become accustomed to new sounds of progress while building
the RV-12. Assembling the RV-12 has it’s own unique sounds … when using the
pneumatic rivet puller on larger assemblies, there is a quick pleasing swoosh …
instantly followed by a solid thud which sounds akin to a detuned metallic Tom-Tom
drum being whacked, the sound of true progress for an RV-12 … a sound I am beginning
to enjoy and look forward to hearing. The hand riveter, on the other hand, is
silent up until the moment the mandrel of the rivet breaks then there is a loud
bang … scary sounding actually, because it sounds like something just broke
(well it was the mandrel of the rivet) and more often than not, the riveter bounces
into something near by creating even more noise. The first box of a thousand
rivets is now empty and the hand riveter has only been needed 9 times which
suits me just fine because I cringe during every use… more of those detuned
metallic Tom-Tom sounds for me, thank you very much.
This morning the stabilator was flipped over so the
other side could be riveted. It is riveted just like the previous side beginning
with the leading edge and working back to the trailing edge.
Forward skin completed, beginning riveting of the
skin onto the spar box.
After the skins are riveted to the stabilator
skeleton, work begins on the splice plate which has a couple of small holes
that need to be matched drilled to the aft flanges of the HS-1201 skins using a
#52 drill bit. These tiny holes will be used later for the safety wire which
will secure the anti-servo tab hinge pins for the right and left hinges. After
the holes are drilled the splice plate is assembled on the back side of the
Match drilling the tiny holes in the splice
plate to the HS-1201 skins.
Next item up for assembly are the notorious
anti-servo hinges (yep, the one I originally miss drilled and need to order a
replacement). The left and right anti-servo tab hinges are attached to the
lower row of holes in the HS-1201 skins. I have to say, the LP4-3 rivets install
much faster than the countersunk rivets I’ve opted to use … it is easy to see
if they are square to the hole, because the nose of the pneumatic rivet puller
does not hide the rivet from view as it does with the countersunk rivets.
Riveting the right anti-servo tab hinge onto the
HS-1201 skin flanges.
Earlier I made mention of using the hand rivet
puller. There are a few places where the clearance is so close, you just have
to use it. There are also a few places where even the hand riveter can’t sit
squarely on a rivet to be pulled … that is not unless the builder follows Van’s
suggestion from very early on in the plans to bend the rivet mandrel a little
and use a wedge to keep square pressure on the rivet head.
Attaching the four ribs which the left and right
aft skins get riveted onto is one of those locations where even the hand rivet
puller will not fit squarely onto the rivets … that is until the rivet mandrel
is slightly bent and a wedge is used.
Close quarters hand riveting tool … notice the
bent rivet mandrels and wedge.
Close quarters hand riveting tool in place on a
rivet with a bent mandrel along
with a wedge to keep the rivet head flush while
the rivet is being pulled.
Looking closely at the above photo, one can
clearly see how bending the rivet mandrel lets the hand riveter slide onto the
rivet mandrel and using a wedge allows even, flat pressure to be placed onto the
head of the rivet keeping it flush to the part being riveted.
Right aft skin ribs attached.
HS-1217 right aft skin ready for riveting.
Setting the last rivet in the top of the HS-1217
right aft skin.
Close up of the flush pop rivets being used in
the place of LP4-3 rivets.
More work to be sure, but the results are worth the
Completed stabilator assembly.
All that is left to do before placing the
stabilator in long term storage is install the counter weights onto the counter
balance arm and bolt on the upper and lower control horns.