Joshua's RV-9A Project

A conglomeration of cabin tasks tonight:

• Riveted the forward canopy decks to the longerons and subpanel.
• Installed the spar upright cap strips with blind rivets.
• Installed the canopy hinge blocks.
• Riveted the parking brake valve bracket to the firewall, and bolted on the valve.
• Attached the brake lines to the valve and torqued.
• Laid out, cut and drilled a removable cover plate for the bottom of the roll bar brace.
• Cleco-clamped my finger and decided to call it a night.

Today’s session was mostly about turning little parts into larger assemblies, some of which got mounted to the fuselage.  Riveted together the fuel pump doghouse, roll bar brace, forward canopy decks, and subpanel left/right sections.

When the assemblies were assembled, I set about installing things…first up, the main canopy latch.  After riveting on the latch bellcrank pivot bracket, the roll bar brackets, and latch weldment were bolted in place, and the latch bellcrank installed and connected to the weldment, complete with cotter pins.  The side latch handle isn’t installed yet (I’m waiting on some UHMW tape to arrive), but the pushrod is assembled, and the knob screwed to the handle.

Before installing the subpanel, the firewall needed to be dimpled for the flush rivets which attach the subpanel ribs.  The top two holes of each were reachable with the squeezer, but the lower three were not.  I ended up using the rivets themselves as a dimple die–”pre-dimpling” the firewall with a couple taps of the gun, with the rib backed by a squeezer yoke; it then dimpled itself nicely as the rivet was driven.  This worked beautifully on the rather malleable stainless firewall; I don’t know how well it would work on an aluminum piece, especially anything thick.

That done, the subpanel assemblies were inserted and clecoed, then riveted to each other, the firewall, and side bulkheads.  Shooting the side bulkhead rivets required undoing one of the adel clamps securing the fuel line and gently bending it out of the way for a moment to allow access for the gun.  Next, the forward canopy decks were clecoed in place.  Also stuck the rudder pedals in, lest that be forgotten until access is made impossible; they’re not yet bolted down, so could be strapped up out of the way to allow for access to the lower firewall.

Tonight’s art project: cut out the templates for the NACA vent installation.

Picked up another quart of paint and sprayed the pile of parts prepped yesterday.  Set to dry overnight, with some assembly on the plate for tomorrow.  Also ordered some wire bushings, extra nutplates, UHMW tape, and a couple other odds and ends in preparation for wiring work.

The big deal for tonight was fitting the subpanel assembly, which needs to be in place before the canopy fitting can begin.  Before putting this in, I clamped an angle across the firewall at longeron level, and bent the top section forward…I can’t find it anywhere in the plans, but Smitty’s log says the bend is 8 degrees, which is what I did, and it worked out perfectly.

On the bench, I riveted the “stub ribs” to the outboard subpanel sections, then clecoed them into the fuselage.  The center subpanel section then fits between the outer two and is clecoed in place.  I left the panel ribs full-size for now, and I’ll deal with them later on, once I know where everything will be in the panel.  With the structure in place, I fit and drilled the top skin, using the centerlined I had drawn on all the non-prepunched pieces earlier.

Of course, with the panel ribs sticking out there, I had to cleco the panel in for a moment to see how it looked.  I wish I had seats to sit in it and check out the fit!  (Though my current panel plan has the bottom extended down by 1.5″…)  It looks more and more like an airplane, even if the cockpit does keep getting smaller.

For kicks, I deburred the spar upright cap strips and slid them into place.  I don’t recall that the manual ever mentioned these, but other folks have installed them at this point with no ill effects.  Of course, they’ll first need to be drilled, deburred, and painted.

Finally, back to the subpanel structure: I drilled the angle clip to the front of the center rib and the firewall, then set about fitting the forward canopy decks.  A pretty easy task, that, just go slow on the trimming–repeated trips to the scotchbrite wheel worked wonders, and gave a pretty tight fit between the forward and aft decks.  Word of warning: if you’ve already run your static tubing forward, remember that it’s under the longeron, and be careful not to drill a hole in it.  Oops.  Thankfully, I ordered plenty of extra and have enough left to re-run that piece; I can cut from the “holey” piece for any behind-panel jumpers I might need.

Rambling begins here: With the exception of fitting the wings, and locating a couple angle clips to attach the panel, I’ve come the the end of the fuselage instructions.  The canopy fitting starts next in the book, and from here, the project could take any number of paths with regard to the order of operations.  Canopy, electrical, avionics/panel, engine, fiberglass tips…the strict order of dependencies sort of disappears.  It seems that it can be taken in pretty much any order, as long as you think through the implications ahead of time, and are willing to live with the consequences.  I think the current plan is to do the canopy first, hoping to get it in the bag by the end of summer.  That will leave the winter for engine and electrical installs, and avionics prewire.  I may curse that decision later, while laying under the riveted subpanel trying to get all the wiring in place, but I think it’s the best decision for progress and cashflow reasons.  I’m planning on a trip to Oshkosh this year, to finalize decisions on all the components (though most of it is pretty finalized in my head already, if not on paper), and take advantage of any screaming deals that may be on offer.  Who knows, maybe I’ll get lucky at the Van’s demo ride line and actually get to fly in an RV, 1000 hours into the build!

This morning, primed the subpanel components and dimpled where necessary for first fitting.  Also pulled the roll bar brace and associated parts, prepped and primed them.  There’s a stack of things awaiting finish paint now, that will likely wait for a bit.  I haven’t yet decided whether to paint the bits between the subpanel and the panel — they’ll be covered by the glareshield when the canopy is closed, but open for viewing with the canopy open.  Leaving the stuff ahead of the subpanel with just the white primer might be a benefit for later maintenance (white reflects light, and that cave area is accessed from underneath with a flashlight…), but the parts aft of the subpanel are all out in the open for maintenance access.  Hmm.

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.