Joshua's RV-9A Project

Hit the ground running today and riveted on the flap brackets and associated angles.  Nothing major different than the left wing process; the only “problem” rivets are those three spar-angle rivets nearest to the top skin, but with added experience from yesterday, then came out passably.  One ugly “smiley” in that awful root-end rivet, but after yesterday’s lesson, I decided to leave it as-is.  After the brackets were in place, I riveted on the gap fairings, and the right wing is done.

Wrapping up, I vacuumed the aluminum shavings out of both wings, then went through them and spot-primed the scrapes and scuffs from the riveting process.  Torque-sealed the fuel tank bolts on the right wing (I had anready done the left wing while it was in the jig).  Bolted the bellcrank brackets in place on the right wing (the bottom bracket replaced by the Trutrak servo mounting bracket; I have left the top servo support bracket out for now, because with no servo, one end is loose in the air, and would be free to vibrate.)  Torqued and sealed the bellcrank bolts.

Spent some time at the end putting tools away, sweeping the shop, and re-organizing to fit two vehicles into the garage bays.

A solid full day in the shop ahead of vacation plans, which resulted in good progress on the wings.  Started out by etching and priming all the flap & aileron bracket parts, plus the gap fairings…a task made interesting by the afternoon’s weather.  I set the parts out on the priming table in the sun, and by the time I had loaded the gun with primer, it had begun to rain.  Inside with all the parts, and start to prime in an impromptu cardboard “booth”…  Soon enough, the sun was back and normal operations could resume.  Primed everything and set it aside to dry, while I worked on deburring and dimpling the #40 holes in the wing skins that attach the gap fairings.

Once the gap fairings were dry, I dimpled the skin attach holes there as well, then set about assembling the aileron brackets.  Had to drill out a couple rivets in two of the brackets when I realized I had misread the plans, and not countersunk for the installation of flush rivets in a few spots.  Oops…not a big deal to fix, though, and the brackets were soon assembled.  Installation onto the wing was relatively painless, the riveting being rather straightforward.

With the aileron brackets in place, I started work on the flap brackets, at which point I realized that I had never countersunk the holes where the skin dimpled nest into those pieces either.  Took care of that, and spot-primed as necessary.  I first installed the rivets that hold only the main piece of the flap brackets to the rib (many of which are squeezable), then went back and installed the bracket-spar angles, then the bracket-skin angles.  It feels more productive to do a whole set of related tasks while a tool (gun, squeezer, air regulator, etc) is configured for a particular situation, rather than having to constantly reset the tool.

The only real problem rivet was the 470 rivet at the root end, where the flap bracket attaches, as it’s a rather long (-9) rivet, and it’s close up to the skin, requiring the use of the double-offset rivet set.  A tool which I have never been satisfied with the use of.  It seems as if the double-offset allows the tool to “spring” and doesn’t transfer the energy of the gun into the rivet nearly as well as the straight or single-offset sets do.  After drilling the rivet out twice (I had distorted the manufactured head with the set), I had a hole that was ovaled in the top piece of metal (the rear spar doubler).  I decided to address that by making that rivet a flush rivet, same as the other two rivets on that row.  The countersink removed the ovalled portion of the hole, and I was able to squeeze the rivet with the 4″ no-hole yoke on the squeezer.  The bugger is still not perfect, but there are many other rivets in that area.  I’ll point it out to my tech counselor for his opinion on the next visit, as well.  Today’s lesson?  If the rivet is good enough, don’t try to drill it out (again!) in hopes of making it perfect…

All in all, the left & right aileron brackets are installed, and the left flap brackets are in.  After all that, it was a quick job to cleco on the left wing gap fairings and rivet them in place.  Only 2 rivets in the gap fairings require use of the gun (where they’re too close to ribs or brackets to fit the squeezer body); the rest are squeezable.  I love my pneumatic squeezer and longeron yoke!

Hoping to get the right wing to the same point tomorrow, then I should be able to roll the wing cart off to the side of the shop and move the fuselage kit out of the second garage bay, so we can get both cars in and secured during our trip.  Looking forward to watching the news out of Oshkosh this week, as well.

The task that never ends…  deburred & edge-finished all four gap fairings, as well as the #30 holes in the spar and ribs for the flap & aileron brackets.  Still need to deburr the #40 holes in the top skins, and dimple where necessary.  The pieces with the little radii, cutouts and such are the worst to deburr — you end up using several different files, including the set of miniature files, plus scotchbrite pads.  Still not as bad as those square corners of ribs, though.

Drilled the flap & aileron gap fairings to the skins and spars, then removed them from the wing.  Deburred all the holes on the components of the flap & aileron brackets, and finished the edges with files and scotchbrite wheel.  With time, luck, and perseverance, I might have all this stuff installed before we leave for AK on the 29th.

Nursing some wrist pain today, so not much productive shop time.  Finished building the wing cart by attaching some swivel casters I picked up last night, and padding the leading edge cutout with foam pipe insulation, then set the completed left wing in the cart.  Looks good, and rolls nicely.  I think there is enough room between the two wing slots that the horizontal stabilizer could be stored on the cart, as well.

Drilled the flap and aileron brackets to the left wing, and pulled out the gap fairings to mess with for a bit.  Torqued the aileron bellcrank brackets in the left wing.  Dimpled the wing walk doubler for the right wing.  Cleaned up the shop a bit, and spent some time just sitting in the shop and looking at things, pondering.

(NB. This post being counted in multiple categories — something which may happen more often, as a work session touches on multiple items.  I’ve split the last several sessions into multiple posts, as the time blocks were larger and more well-defined.  In the case of multiple categories on a post, each category will total the entire number of hours from the session, but the “grand total” will count it only once.  I wish there was an easy way to resolve this, but it is what it is–and since the hours tracking isn’t a requirement of any sort, just for my curiosity, not a big deal.)

While waiting for the water level to drop in the fuel tank test, assembled and drilled the four aileron brackets, as well as fabricated the aileron stops out of the supplied angle.  Set the brackets aside for drilling to the wing after we flip it nose-down in the wing cart.  Pondered over the flap brackets, for which there are several parts to fabricate from angle stock, along with much drilling to the wing.  Also pulled out the rest of the aileron pieces and removed the blue plastic.