Joshua's RV-9A Project

Etched the subpanel components for priming.

Completed the initial installation of the roll bar by fitting it to the fuselage and drilling, countersinking, tapping as required.  Some trimming of the aft ends was necessary for a good fit, as noted in the plans.  Clamped and drilled the connector channel and associated angles as well.  The roll bar is surprisingly solid, even without being completely bolted in.

Next, on to the upper forward fuselage/subpanel area.  A  bunch of small angles needed fabrication, and the only snafu was when one pair fell off of the bandsaw into a bucket of waste oil…so a second set of those were made.  Fabricated the “stub ribs,” trimmed various things according to plans, and drilled them together.  The manual says “drill the hat channel to the aft face of the subpanel”…don’t do it!  Despite what the manual says, the drawings clearly show the hat channel on the forward face of the subpanel, and the hole pattern is slightly different left/right, so it can’t just be flipped…I’ll have to order a new piece.  For now, this isn’t critical (it is the bracket that holds the canopy jettison pivot assembly), so I drilled a few holes to hold it in place for spacing until a new one can be fabricated.  Finished up by disassembling the whole thing and deburring the bits…decided I didn’t feel like etching more parts (didn’t I just do that?), so I called it a night.

I am seeing here where it would be expedient to have a panel plan in place (at least the instruments and radio stack locations nailed down) — things like the final location of the left/right panel ribs would be much easier to deal with on the bench than after parts of the assembly have been riveted in place.  I’m going to look at other folks with panels similar to mine to see if I can come up with anything…or I suppose I could cut the ribs flush and then wait until later to rivet in the forward portions (I know at least the left rib will need to move).  There are a couple almost identical to what I’m planning, but they are both sliders, so the structure is all different.

(900 hours tonight)

Primed the roll bar components and other misc bits from yesterday’s prep session.  Also deburred , etched, primed and dimpled the top skins and J-stringers, since they need to be in place for the roll bar fitting, to hold everything at it’s proper location.  I have not painted the roll bar parts yet, since there is still some fitting to do; I will paint it as an assembly in the next batch after fitting, along with the channel that holds it in place.

Once the primer was dry, the roll bar was riveted together, then the brackets were clamped, drilled, and riveted together, then fit and drilled to the fuselage.  Spacers were fabricated from .063 stock to go outboard of the brackets (yes, the angles are supposed to overhang the fuselage and be filed, but my roll bar ended up a bit narrower than expected, and this will actually work well to allow a gap for gluing the forward line of the rear window to the roll bar).  That is not a fun filing job.

With all that out of the way, I riveted in the 709 bulkhead and the top rib behind the baggage compartment, and clecoed on the top skins in preparation for tomorrow’s work.  I drilled the two holes from the top skin into the roll bar brackets and spacers at #40 for now.

Finished fabrication of the roll bar by drilling the forward channel to the join strips, then took it apart for deburring.  Etched the pieces of the roll bar assembly, along with some other parts collected over the last couple weeks (boost pump doghouse, brake bracket, etc.)

Started work on the roll bar (aka cabin frame) today.  Laid out and cut all the angle pieces and plates necessary, and figured out how it all comes together on the fuselage.  With those pieces at the ready, I pulled out the roll bar channels and designated them as fore/aft left/right for reference.  I marked out guide lines at the proper dimensions on the workbench, and went to work fitting.  I had to trim a bit from the inboard top end of each side to get the width correct; once that was done, the splice plate was drilled in place.  With the whole thing clamped and clecoed to the bench, I marked the top and bottom strips and drilled them in place, starting in the middle and working out, clamping between each drilled hole.  The angle drill attachment was necessary here, because of the proximity to the benchtop.  After both strips were drilled to the aft channels, they were removed for a quick deburring and chip removal, with the thought that it would allow for a better fit and more accurate drilling when the forward channels are added tomorrow.

Lots of little tasks to keep going on today…

Riveted the canopy decks in place!  This may come back to bite me later, but the instructions have this done long ago, and reaching over the fuselage witht he clecoes stabbing me in the gut was getting old.  Bucking these was actually quite easy; the tungsten bucking bar fits in the gap for all but the 4 rivets just aft of the spar upright, and for those, I just inserted the bar into the “channel” farther aft, positioned it horizontally (completely inside the channel), then slid it forward and held it up with my fingertips through the gap.  Method of assembly: completely remove the canopy deck and gusset, set all the rivets on the forward side of the bulkhead that hold the thick angle on the back, then install the gusset and rivet the 4 rivets on the top.  Finally, put the canopy deck back on and set all the rivets along the longeron.

Turned threads off of fuel vent fittings by chucking them up in the drill press; made the angle cut, and deburred.  Still need to find screen and attach it before these can be installed for good.  Installed fuel vent lines from vent fitting, to stub through fuselage side to tank.  Installed rubber grommets through side skin.  I spent quite awhile bending the first one to fit right, then the other side was very easy, just duplicate it in mirror image on the bench, and it dropped right in with only minor tweaking.

Installed rudder cables in the fuselage, and adel clamps at aft end.  (Need to torque and mark those screws.)  The string I had run earlier in the baggage area worked perfectly.  Installed the swivel fittings into the static ports and ran the static line between them, including the tee.  Ran static tubing forward, leaving a coil stored along the side of the fuselage with plenty of length to connect to instruments later.

Installed the flap actuator center bearing block nutplates, followed by the flap actuator, motor, and side covers.  Removed the side covers and set aside for later.  Need to order the Ray Allen POS-12 flap position sensor, which will mount somewhere in this area.

Installed Andair fuel valve to selector plate.  Used AN3 bolts for now, later I will probably replace this with different #10 hardware, some sort of more attractive screw.  Need to order more K1100-3 nutplates, since I stole from the supplied stock to mount the fuel selector.  Removed the elbow fittings from the selector, lubed the o-rings with EZ Turn, reinstalled, and staked the screws.  Like everyone else says, this valve is a work of art, and it’s hard to resist playing with the knob…no wonder it comes with a big red tag attached warning against “excessive dry operation.”

Cut down height of the boost pump “doghouse” cover by 1 1/4 inches, since the Andair pump is not as tall as the stock (AFP) pump and all the tubing/accessories that go with it, and more open cabin space is better.  I could probably have cut another 1/2″ off of it, even.  (By this point, it was getting late and I was working without stopping for many pictures.)  I used the opposite cover to mark a cut line 1 1/4″ down from the top of each, then cut and deburred, then used the cut off piece to re-drill the hole pattern in the top of the shortened side.  This seemed easier than cutting from the bottom and re-bending the flange as I’ve seen others do.

Began work on fuel pump installation, looking at how it will all fit together, and printed off the installation diagrams from Andair’s site for reference.

Finished the gear mount install by drilling the right side skins and bolting in place.  The right side weldment had a gap between it and the fuselage side (not uncommon, or so I’ve read), so I fabricated a shim out of some scrap stock, to fill the gap and prevent the side skins from bowing in under the torque of the bolt.  As a result, I upsized the bolts and added a thin washer, to get proper thread engagement.  Drilled and countersunk the forward holes, and installed those screws as well.

Next, I re-installed the brackets that hold the cover plates ahead of the main spar; the bottom screw is tricky to get in, as the screwdriver can’t get a straight shot due to the tube of the gear tower being in the way.  I tried a number of types of screwdrivers, including a right-angle gizmo, but a thin-shaft regular driver ended up working the best, even though it was cocked at an angle.  The clockwise side of the head got a bit boogered, I believe, so these screws will be one-time use: if they ever need to come out they will be replaced.  I also sanded a curve into the bottom of these brackets, to provide additional clearance to the gear leg tube which is very nearby, and was barely rubbing on the right side.  Test-fit the forward covers and filed the slots at the bottom slightly, to provide better clearance from the floor stiffeners.

Looking around for other odd tasks, I decided to put in the gusset plates that reinforce the seatback brace-main longeron joint, and drill those holes to final size for rivets.  Five holes per side, not difficult; the forward two on each side are countersunk.  Those plates are now clecoed in place, and I believe the canopy decks can be riveted at any time.

No, it’s not the pre-landing checklist, it’s today’s work session…  In the morning, I was able to get the riveting done on all the pieces that were recently primed: the forward tunnel covers, fuel valve cover, and flap parts.  Many nutplates were installed, and the flap assembly was clecoed in place for now (still waiting on the missing nutplate to arrive for final install).

The evening session focused on the next step: gear towers.  I ordered a .311 reamer from Avery Tools, which arrived this morning, and was shortly put to use on the gear legs: first, I cleaned the inside of the towers and the outside of the gear legs with a scotchbrite pad, then wiped everything down and coated with some light oil (I just used pneumatic tool oil which I happened to have handy).  This allowed them to slide together with relative ease…a couple taps with a rubber mallet and everything was aligned.  With Boelube on the reamer and a dab inside the pre-drilled hole, it was easy to ream the hole to size.  Disassembled and deburred, and the legs were set aside for later use.  The gear towers went into the fuselage, after trimming away a bit of the aft end of the outboard floor stiffeners to allow clearance for the mount.

Of note is the brake fitting holes which were drilled back in the bottom skin prep phase…while the right hole aligned well, the left one was off by about 1/3 diameter, compared to the hole in the weldment.  Not a big deal, I just used the unibit to move it in the correct direction, large enough that the fitting could slip into place.  I also upsized the bolts along the top of the spar to -13A’s, which means I’ll need to order a fistful of -13A replacements…it just looked better, as the nuts have only about 1/2 thread showing with the -12′s.  This is apparently a common issue, and other builders have also upsized to the -13A’s, though Van’s says it’s unnecessary.  For ease of fitting the gear towers, the outboard snap bushing was also removed, and reinstalled after the towers were bolted in.  A long open-end or box-end wrench is a necessity here, to reach the nuts inside the bottom of the spar.

The next step was to drill the holes and install the fasteners along the side skins.  The 5 aft bolts are easy; they are drilled using the pre-punched holes in the skin.  The 2 forward holes are drilled through the skin using holes in the mount, one of which is tucked in behind a bulkhead flange and not easily accessible.  Following the lead of others, I used a #40 bit to drill through the bulkhead flange, then out through the mount and side skin.  I enlarged that hole from the outside to #30, then to final size for the AN3 screw, and countersunk.  The most difficult part of the operation is fishing the chips out from between the side skin and bottom skin…I made good use of the “chip chaser” tool, along with a thin steel ruler.  The left side is drilled, the right side will get done tomorrow.

(An aside: I watched an online EAA video last night about torque seal, and learned that I’d been doing it partially wrong…the torque seal is supposed to be applied from the nut, across the washer, to the base material, but not from the nut onto the threads…apparently it can damage the threads on later removal.  I’ve done quite a few with a stripe all the way from the base material to the threads, so if those need to be removed later, the threads will be inspected and replaced as needed.)

Disassembled the fabricated parts for the flap actuator, aileron trim, and forward tunnel covers.  Etch, rinse, dry, then prime everything, followed by spraying paint on the visible surfaces.

Went to drill the nutplates for the center bearing block on the flap actuator while the primer cured, and discovered that the one -3 single-leg nutplate that is needed is missing in action.  Searched all around, and looked at the parts list–it appears to be the only one of these (MS21051-L3) that is sent.  My theory is that it must have gotten caught inside the flaps at the bottom of the bag and tossed out with the supposedly-empty bag, as I don’t even have a drawer in the bin wall marked for it.  An 80-cent part from Van’s…sigh.  Forward progress may stop here for awhile, as everything I’m looking at doing is waiting on some part or another (gear mounts need a reamer, flaps need a nutplate, center tunnel covers need the boost pump doghouse, etc…)

Started out with some monkeying with the center tunnel covers–match drilling various parts, deburring everything, and modifying the fuel valve plate to remove the trim cable mount.  Done and set aside for paint and modification for the boost pump.

First fitting of the flap system today.  Lots of parts needed fabrication: brackets for the top & bottom of the actuator channel, mounting angle and plate for the motor, a bolt spacer, etc.  Drilled the end of the actuator arm for the safety wire hole, and also drilled the rod end, since you can then wire the rod end to the actuator, rather than around the bolt (a joint which rotates by design with each flap extension/retraction)…this method of safetying seems to be favored among builders, though I need to look and see just how they’re running the wire.  I tried it a couple ways and finally settled on one, though it still seems loose to me, so I will see what others have done and probably re-do it; safety-wiring is a brand new skill to me.

With all the pieces fabricated, it’s time to fit it together…first, the arm weldment is bolted in place and the center bearing block fit; this is bolted near the tunnel, so the aft tunnel cover must be notched to fit around the bearing block.  The actuator channel is drilled to the cross-brace, the motor mount drilled to the channel, then the side panels put in place to drill the rear channel, whose bracket was previously drilled for the floor screws using the tunnel cover as a guide.  (It’s not as complicated as it all sounds…)  The forward tunnel cover also needed to be trimmed a bit; the bottom angle needed a more gentle curve to nest into the brackets that hold the flap actuator channel, and the top piece was too long (I expected this, having left it a bit long intentionally to cut it for a good fit).

A few more things to wrap up (drilling nutplates, etc) and then I will have to do another batch of prep/prime/paint so some of these things can be installed.