Now that ribs are attached to the aft portion of
the left wing spar, the next components to be assembled onto the left wing are
the W-1208 nose ribs. The plans call for starting at the outer most rib
attach clip and installing the five W-1208 nose ribs which previously had the
aft flanges removed. Access for the pneumatic squeezer is good so these ribs
will be attached onto the rib clips with AN470AD4-4 rivets in the place of
LP4-3 pop rivets.
The five outboard W-1208-R nose ribs with the
aft flanges removed ready for attachment to the left wing spar.
Not much progress was made due to honey do
errands which took up the entire day, so only had enough time to reposition the
spar and rivet the first W-1208-R rib onto the outermost rib clip.
Using the pneumatic squeezer to attach the first
of the five W-1208-R ribs
with the aft flanges removed onto the left spar with
AN470AD4-4 rivets.
Now that the skeleton assembly has been laid horizontally
to make squeezing the rivets easier, I took some photos of the vinyl tubing being
used to keep the W-1210 rib flanges tight to the rear spar while squeezing the
solid rivets.
The pneumatic squeezer along with a piece of the
vinyl tubing being used to keep flanges tight to the aft spar.
Note how the piece of tubing is just a little
longer than the shaft of the rivet so the tubing compresses against the parts being
riveted holding them tight together before the rivet begins to compress.
Vinyl tube over the shaft of one of the rivets
attaching the aft spar to the ribs … ready for the pneumatic squeezer.
Using the pneumatic squeezer to set an
AN470AD4-4 rivet used to attach the aft spar onto one of the W-1210 ribs.
I had a feeling the four rivets going through the
flaperon hinge bracket would be challenging to set with the pneumatic squeezer …
and my suspicions were proved correct. The
top rivet was a piece of cake the bottom two rivets were difficult and the next
to the top rivet proved to be a total drag and ended up being a time sucking
abyss … about 40 minutes worth. I was about to throw in the towel and use a
rivet gun and bucking bar but finally got the access I needed. I was trying all
different combinations of yokes and rivet sets.
There were two issues; the hinge bracket was interfering
with the pneumatic squeezer body along with a rivet that was already set (a
part of the hinge bearing attachment) which was hitting the yoke and further preventing
a good square seating on the head of the rivet. The issue was mostly resolved by
using a taller rivet set on the factory head of the rivet and a thin large
round set on the shop head side. Then the pneumatic squeezer piston was carefully
deployed so the squeezer body would push back and clear the one previously set rivet
that was in the way. Once all that occurred, alignment was close enough to being
almost square to finally set the rivet.
One can see the primer took a little abuse while getting
the second rivet from
the top down set. It was a fight, so will need to touch up
the primer a tad.
The good news … all solid rivets were used to
attach the aft spar to the W-1210 ribs. As previously mentioned, AN470AD4-4
rivets were used on the aft spar to rib junctions. The rivets at the inboard
end of the aft spar where the doubler plate resides required AN470AD4-6 rivets
and the four rivets that go through the flaperon hinge assembly and into the
inboard W-1210-L rib (the ones that gave me a fight) required AN470AD4-7 rivets.
The aft spar of the RV-12’s left wing riveted in
place using all solid rivets.
Now that the aft portion of the left wing
skeleton is completed, the assembly finally looks undeniably like a large part belonging
to an airplane.
After the inboard W-1210-L rib’s rear flange was
match drilled to the spar’s flaperon hinge bracket, the rear spar was removed to
allow deburring of the holes just drilled. Once the holes were deburred, the
rear spar was clecoed back onto the rear flanges of the W-1210 ribs and the
assembly is now ready for riveting.
Finishing the clecoing of the left wing’s rear
spar onto the aft flanges of the W-1210 ribs.
A quick check revealed the pneumatic squeezer
fitted with a longeron yoke is able to access the rivet holes nicely.
Admittedly, I did not check the clearance at the flaperon hinge … it looks
tight there, but since all the other rivet holes can be riveted with solid
rivets, that is what I’ll be doing and will deal with the hinge later. Using a rivet gauge, it was determined the proper
size of rivet to rivet the rear spar onto the W-1210 rib flanges would be an
AN470AD4-4 rivet … so they will be used in place of the LP4-3 pop rivets the
plans call for.
Squeezing the first of many rivets attaching the
rear spar onto the W-1210
ribs with the pneumatic squeezer using AN470AD4-4
rivets.
At first it appeared to be a good idea to keep
the wing assembly vertical (as in the above photo) so I would not have to hold
the mass of the squeezer with my still quite sore right arm. While this was a
good idea and did work, it was very difficult and time consuming to keep the vinyl
tubing over the rivets (remember the vinyl tubing trick from a previous post?) and
position the squeezer while gravity is working against you. Tomorrow will try
to lay the skeleton assembly horizontally so the vinyl won’t slip off the
rivets … will just have to tough it out with my sore arm or try holding the
squeezer mostly with my left hand.
The vinyl tubing I’m referring to has been
discussed earlier, but basically is a small piece of tubing a little longer than
the rivet which is slipped over the shaft of the rivet prior to squeezing. The
idea here is as the pneumatic squeezer’s piston begins to pushing out, it hits
the vinyl tubing first and compresses it into the flange of the rib keeping it
tight to the rear spar before the rivet begins to be compressed. This keeps the
parts compressed tightly together before the rivet begins setting. Since the vinyl
is malleable, it just collapses under the pressure and does not interfere with
the proper setting of the rivets. I’ll try to remember to post a photo tomorrow
of the vinyl tubing in use.
The riveting the remaining two W-1210 aft ribs
onto the left wing spar was the first order of business today and was completed
in short order this morning. I felt good
about being able to attach the W-1210 aft ribs onto the left spar using almost entirely
solid rivets … in fact, of the 84 rivets, only one is a LP4-3 pop rivet and
that rivet is on the inboard rib doubler where it is one of 12 rivets.
The RV-12’s left wing spar with all the W-1210
aft ribs riveted in place.
The left aft spar is temporally attached to the
W-1210 aft ribs so the flange on the inner most rib can be match drilled to the
aft spar’s flaperon hinge assembly. Two of the holes on the rib’s aft flange already
match two holes on the flaperon hinge assembly so they are clecoed to hold the alignment
while the remaining two holes in the aft spar’s flaperon hinge are used as
templates to drill the remaining two holes into the inner rib’s aft flange.
Match drilling the left wing’s aft spar flaperon
hinge to the W-1210-L inner rib.
Did not have much time today do accomplish more, so
hopefully tomorrow the rear spar will get deburred and subsequently riveted
onto the aft flanges of the W-1210 ribs.
It has been a sad week at DOG Aviation dealing
with the loss of Jan’s brother-in-law Jim, a beloved family member who will be
sorely missed. Needless to say, not much time was spent in the shop
the last few days but did manage to continue attaching a few more ribs onto the
left spar today.
Continuing the attachment of W-1210-R ribs onto
the left wing.
Attaching the lone W-1210-L rib onto the left
wing spar’s inner most rib clip.
My friend Bernie swung by this afternoon to see how the
project was going so he was recruited to add another rib onto the left spar before
calling it quits for the day. Now there are only two aft ribs remaining to be
riveted.
Bernie trying out the pneumatic riveter by
setting a few of the rivets attaching the W-1210-R ribs onto the left spar.
Ten of the twelve W-1210-R aft ribs are now riveted
onto the left spar along with the lone W-1210-L rib which is the inboard most
rib. Should be able to attach the remaining two aft ribs tomorrow and possibly begin
working on the nose ribs.
Construction of the RV-12’s left wing began late
this afternoon. Just to make sure the easy seems confusing, and to keep one on
their toes, in good form Van’s assembly instructions call for constructing the LEFT
wing using almost entirely RIGHT ribs except for two. After a little head
scratching and looking ahead in the plans to verify the right wing is
constructed using all left ribs except for two right ribs, assembly began.
Assembly of the left wing begins with the plans
calling for the W-1210 aft ribs to be riveted onto the left spar first. The ribs
are to be riveted onto the spar using LP4-3 pop rivets. However, since access is good for using the
pneumatic squeezer, I’ve once again elected to use solid rivets to attach the
ribs to the rib clips instead of using LP4-3 pop rivets. By using a rivet gauge, it
was determined the proper size of solid rivet for riveting the W-1210 ribs onto
the rib clips would be AN470AD4-4 rivets.
The first W-1210-R wing rib clecoed onto the
left wing spar and ready for riveting.
About to set the first of six AN470AD4-4 rivets which
will attach a W-1210-R rib onto the left spar’s outboard rib clip.
No sooner than the second rivet was set in the
first rib and I was called off the project to put on a Molly Maid hat and help
out with sprucing things up for unexpected out of town company. Once Molly Maid
duties were completed, RV-12 wing assembly resumed and had enough time to rivet
the first three W-1210-R outboard ribs onto the left spar.
Three ribs down … twenty four more to go.
The 120 degree machine countersinking for flush
rivets on the left wing spar was finally completed today. I knew this was going
to be another mini project because there were a lot of holes on the spar to
countersink, especially near the inboard portion where there is extra support for the wing walk area on the wing. Of course, machine countersinking
takes far more time than dimpling, so overall it is a mini time sucking abyss.
Getting to this point has been a few days in the
making, but there has been a lot going on around here as of late, plus have
only really wanted to spend a limited amount of time in the shop so my arm doesn’t
get any worse. The elbow is beginning to feel much better now, but it does not
take much in the shop to make it complain, so have only been working an hour here
and there so it stays on the mend.
The home stretch - the end is in sight, only 18
more holes left to countersink.
In a previous post I mentioned I’ve been
spinning the countersink bit slowly by keeping the air to the drill turned down
to aid in eliminating chattering and hole elongation. Then discovered by starting and stopping the
countersink bit it appeared to cut faster than keeping the countersink bit
spinning slowly. That method truly does cut the countersink the fastest … at
least it does for me. Perhaps this is because the use of Boelube on the hole and
cutting bit makes a slick barrier for the bit when it spins faster. Don’t really know why, but one adapts to what
works well at the moment.
Finished inboard portion of the machine countersunk
left wing spar … notice the hole
spacing is tighter here compared to further
outboard as seen in the first photo above.
Now that the left wing spar is finally
countersunk, the left wing skeleton will take shape rather quickly as the ribs
are attached … and the available space at DOG Aviation will be diminishing just
as quickly.
