Joshua's RV-9A Project

Spent the day working on various items, mostly in the cabin area.

• Hooked up the Garmin GPS 18x-5Hz to power and a computer to program & test it out.  Solid lock even inside the house.
• Printed real labels for the various wires I had labelled with tape after I ran out of label stock.
• Installed a connector on the #2 OAT sensor, installed it in the wing, and added connectors to the wing end of the OAT cable for both sensors.

• Drilled the #2 EFIS tray to the panel, the #1 tray will come with the avionics order…hopefully next week!
• Deburred and primed the panel and riveted the top angle on, after removing a bit of one ear on the angle to allow for the #1 EFIS tray.
• Riveted the canopy seal support angles to the subpanel.
• Removed the right side panel-subpanel  rib as I did earlier on the left; though I spaced the radio stack to not interfere with the rib, the angle to mount the stack would overlap the rib, and there would be no clearance for the mounting nuts.  This could be shortened by the thickness of the angle and mounted behind it, or (easier) moved to the right by 3/4″ of an inch of so.
• Added nutplates to the panel flange, and the subpanel bracket, to bolt the throttle quadrant mount to.  I’m making a conscious effort/decision to use nutplates under the panel, and have bolt/screw heads face down, so that future maintenance will be easier.  Also any electrical connection that must be made with solder (such as master and starter switches) will have a connector inline, to allow the component to be removed and serviced on the bench, rather than soldering in situ, laying on my back working over my head.
• Fabricated a bracket that straddles the throttle quadrant, to allow mounting of the fuel purge and center cabin heat controls on either side.  Painted and temporarily installed with the quadrant to work out cable routing.  Quadrant and bracket are mounted via the same bolts, and the bracket dresses out the quadrant install well, I think.

• Finished installing the firewall eyeballs for the throttle, mixture, and center cabin heat controls.  These buggers are time consuming…but only two left (purge & alt air).

• Fit the center cabin heat cable and figured out the cable route.  Put the right seat in to sit and work out a location for the right-side heat cable.  Decided to put it under the right air vent, against the sidewall.  So, fabricated a mounting bracket and painted for installation tomorrow.
• Riveted the left side vent bracket in place and installed the vent.  (Right side tomorrow, after the heater cable bracket is attached to it.)

Passed 1200 hours in this session.

Panel placards arrived today, they look good.  All the holes are perfectly aligned with the panel cutouts, so the drawings and CNC cutting worked well on both ends.

Primed & painted a few small pieces for installation in the next session.

Cleaned up the bench and found the countersink cutter, so I countersunk the vent brackets and panel top, then pulled everything apart for deburring and primer.  The panel won’t be primed/painted yet, as it will need more drilling and such to mount the avionics.

Wired the map lights and baggage lights to the dimmer module, temporarily connected the dimmer pots, and put some power to it; it’s fun to see things light up.  I also clamped an LED strip along the bottom of the subpanel to test if it would work for cabin/footwell lighting.  It did, so I installed that as well, though the wiring is not yet final.

Drilled the large holes in the firewall for the throttle, mixture, and center cabin heat cables.  Tomorrow I’ll drill the screw holes to hold the eyeballs in place.

With the CNC cut panel in hand, I set to work getting it ready for installation.  This meant that all the switches and stuff I put in for fun had to come out, but I knew that was coming.  First, I drilled the holes for the RH panel rib using the stock panel as a template.  I discovered that the panel was rubbing the canopy deck on the right side (I’m guessing that the canopy decks and/or longeron heights are not 100% symmetrical), so I trimmed a bit of material off the edge to make both sides match and fit nicely.

The big piece to fabricate (it’s been awhile since I had a “make from” instruction) is the reinforcing angle which runs along the top of the panel and stiffens it.  This is just a piece of 3/4″ leg angle, but it it tedious to make because it needs a bunch of slots made in it to allow it to bend around the curve of the panel top.  While I was on that sort of a track, I also finished up the canopy seal holders which needed the same treatment.  I ended up drilling the radius holes with a #30 bit (R-1/16) on the drill press, then marking lines for the 15* slots and cutting with a hacksaw, as the angle is too long for the bandsaw.  Clamping to the bench and filing both sides, then the radius, finished it off; after that it was a relatively easy task to drill to the panel.  That particular job ended there, as I can’t seem to locate my #40 countersink cutter.  There’s also two small angles that run vertically at the outboard edges of the panel, so those were made and drilled too.

With the panel clecoed in place, I set to work on the vent brackets.  I’m going off-plans here, since I am installing the SteinAir vents, which don’t mount with screws like Van’s vents do.  I decided to cut a couple pieces from the stock panel blank, keeping the bottom flange, and nest the radii together with the vent bracket behind the panel.  A piece of angle attaches the bracket to the side skin at the four pre-drilled holes.  Easy enough in concept, but fitting it all up and drilling everything took some time.  I also added an additional screw hole to the lower part of the panel that will affix it to the vent bracket; this should provide some extra solidity to the switch row.

Pulled the panel out and deburred the work that was done, then drilled the canopy seal holder angle to the subpanel.  I’ll need to do a priming/painting job sometime soon here so things can be assembled.

One more project…installation of the throttle quadrant.  I’ve mapped this out in my head, so it wasn’t that big of a deal, and it was fun to see it in the plane.  I cut a couple pieces of angle to run from the panel to the subpanel, providing a place to attach the TQ–here I’m using hardware store angle as was suggested by someone on the forums, since it doesn’t have a radius on the inside of the vertex, which allows the TQ to seat firmly inside.  Another piece cut from the stock panel blank provides extra length at the subpanel to compensate for the added length of the panel.  Securing the angle pieces to that bracket with bolts will give a handy place to use adel clamps for the purge & cabin heat cables that will go to the outsides of the quadrant.  The front of the angles are secured directly to the bottom flange of the panel.  I was going to mount the quadrant on center, but sitting in the plane fooling with various positions, I ended up cheating it just a bit to the right, so the flap switch would be easy/comfortable to reach with my hand on the throttle lever.  It’s only 1/2″ or so off center, so not very noticeable and not encroaching too much on passenger leg room.

Looks like I might be forced to clean the shop tomorrow so I can find that countersink bit…

Not alot of visible progress for the hours today, just working on a number of small things.

• Assembled a .040″ restrictor orifice into a -4 straight nipple fitting, and installed into the #3 cylinder for pickup of manifold pressure.  The #10 sized orifice from McMaster-Carr (2943T887) works nicely in a -4 fitting size, just requiring the fitting to be tapped.  After tapping the fitting, I installed the orifice with high-temp threadlocker.  I also tapped the orifice from the hose side, rather than the cylinder side, so that if it were to somehow work loose, it could not travel into the engine, but into the hose.

• Finished installing the wing wiring connectors by terminating the wires on the left wing.
• Reinstalled the fuel vent line tubing that passes through the fuselage sides; torqued the fittings.  Cut the vent lines to proper length.
• Smoothed and flared the ends of the fuel pickup and vent tubes that protrude from the fuselage.

• Riveted the doubler plate for the fuel pump to the tunnel cover.  Fabricated a pair of stiffener angles for the same cover, to beef up the sides of the assembly and reduce vibration.  Affixed the pump to the cover plate, and test fit it in the fuselage; tweaked a couple fuel line bends to get the selector-pump-firewall plumbing aligned.  Cut and terminated the fuel pump wires.

• Put some temporary zipties on the tubing in the tunnel to hold things in place for now.
• Removed the firewall passthru fittings to fabricate and install a doubler on the inside of the firewall.  I had used the thick aluminim spacer/washers that Van’s sends, but there was too much flex in the FW still for my taste; this beefed it up nicely.  Reinstalled fittings with doubler aft and spacers forward, and torqued fuel & purge return lines at the firewall.

• Installed the closure pieces for the inboard seat pan ribs, that bridge the gap which is cut to allow installation/removal of the control column.
• Temporarily installed the roll trim assembly in order to find the correct angle for the metal tabs that bolt to the lower end of the control sticks, so I could torque the bolts on the rod ends that tie the sticks together in roll.  Also to see how the trim goes together.  Followed the plans for setting the spring lengths, but they seem as though they might be overly tensioned…need to see where others have ended up on the length.  The issue may be that the plans have you use the forward-left-most stick position to set the spring lengths, and without the elevators and ailerons attached to hit their stops, I suspect the stick travel is a fair bit more than it would be normally, which would result in stretching the springs excessively.  So, setting the spring length may end up part of the after-final-wing-mating task list.
• Also torqued the bolt for the elevator pushrod at the control column.

I found that the Goop used on the stick grips cured well, and the grips are solid.  Also sent off what I hope will be the last of the minor revisions on the panel layout, so that should be cut sometime next week and on its way.  Hoping to have the harnesses from SteinAir sometime soon, as that’s all I’m waiting on to wrap up the airframe wiring.  Had made contact with the engravers about doing the placards for the panel, but they seem to be slow on the email (or at least haven’t replied yet), so I’m not sure the current status of that piece.

Working on several areas today:

• Installed 1/8″ NPT to barb fitting nipples in the transducer manifold for the manifold pressure line; one will feed MP to the P-Mags, the other to the sensor for the engine monitor screen.
• Fit and temporary-installed silicone tubing from the manifold to the P-mags, and a stub for the MP sensor when it arrives.
• Measured for fuel hoses and pressure sensor lines (fuel, oil, MP) with a piece of tubing.  I should now have the list of most of what I need to order, except for the oil cooler hoses, which I won’t be able to measure until baffles and cooler are installed.
• Ran wire from the panel to the wing roots, forward of the main spar, for the fuel level sensors; wires I forgot in the earlier wiring work to those locations.
• Pulled wires to the FWF electrical area, for master contactor, starter engage, and starter engaged annunciator.  Terminated and landed the contactor ends, and verified proper operation of the contactors.  Secured the wires, at least for now.  These should eventually get high-temp tie-wraps.
• Wired the connectors on the stick grips, and glued the grips on with Goop.  I’ll have to see how it cures in a few days, whether it’s too soft for this or not.  I believe it will be removable with enough force, which would be a positive thing if I ever wanted to change grip function (add a switch, for example) or if a wire needed to be repaired.  But, I want it to feel solid, and the grip not to move or flex under normal use.
• Put connectors on the master keyswitch and the aux PTT switches.  These connectors aren’t strictly necessary, as the wires could be soldered to them inside the plane, but soldering is a much more pleasant experience when not carried out upside down; I also want to be able to remove the panel without the need to unsolder things, which means a connector on the master switch, since it installs from the front of the panel (unlike the toggles, which install from the back with nuts on the front side.)  Installed the aux PTT switches, and glued a tie-wrap base to the underside of the forward canopy decks to secure the PTT wires and static line.

I’m trying to close out wiring and stuff aft of the center section, so that the wiring runs in the tunnel can be cleaned up and tied down, then work forward with the wiring.  To that end, I finished running all the wires I could aft of the center section, which today was the ELT remote (4-22 shielded) and the GPS signal run (3-22 shielded) which will feed both the ELT and the APRS tracker that I’ll mount in the same area.  That finishes the aft wiring, except for five wires: 4 audio cables (pilot & pax headset & mic runs), and the cable(s) to the magnetometer(s) — I’ll run wires for 2, since each screen with airdata needs it’s own magnetometer — all of which will be included in the harness kits from SteinAir, so I’m waiting to run those.

With most of the wiring aft of the firewall in place for the time being (until the harnesses are ready in a few weeks), I moved on to other aft-of-the-spar tasks — namely, the control system.  I removed, primed, and reinstalled the pushrod that connects the two sticks in the roll axis, and built the forward elevator pushrod, as well as bent and installed the tabs that bolt onto the control column to connect the roll trim springs.  I used a piece of light safety wire to thread the washers and rod ends into the sticks properly, but still need to torque those bolts.

I finally got around to some housekeeping — vacuumed out the forward part of the cabin of metal shavings and debris.  I need to reclaim my shop vac from the office and vacuum out under the seat pans, as I’m sure there is schmutz down there as well.  Also, taped over the intake to the fuel servo to prevent the shop spiders from taking up residence in the induction system.

Another task for the evening was to cut the sticks down.  I measured both sides and decided to cut off enough to compensate for the length added by the stick grips (~ 2.5″), plus another half inch.  Some builders cut them way down, but I’m taking a wait-and-see approach to that, as it’s easy to cut them down farther later, but far more difficult to add some back on.  After I cut them down, I (of course) had to load in the left seat and panel blank, and test it out.  The length seemed pretty comf0rtable to me, and it does not appear that they will hit the panel (using a ruler to simulate the ~1.5″ I’ m adding to the bottom of the stock panel.

I’m working with a gent who posted on VAF about doing some panel cutting for the cost of materials and shipping, and I think we have the measurements worked out; I’ll be drop-shipping an oversize blank to him this week for cutting, so that’s coming together as well.

Spent the morning at the Minnesota Wing meeting, talking and looking at a local RV-7 that was recently finished, which provided some good inspiration to move ahead on the FWF stuff; also had the change to talk to folks about some open questions: mufflers and heater boxes, seat heat switch location and wire routing, transition training, and so on.  Notes to self: the Torx screws on tips and hex-heads for interior panels look nice; heated seat wiring can be run out underneath the flap motor housing, and the cushion cables are long enough to reach; relays can go in the flap housing with switches on the crossbar (though they are hard to reach in flight, it cuts down on wiring run through the center section).

Back in the shop this afternoon, my goal was to get most of the firewall components installed and ready to hang the engine tomorrow.  Number one on the list was the heater boxes.  I chose to mount one in the center, feeding into the stock diffuser box; the second one is placed on the passenger side, far outboard.  I oriented that one with the outlet (which dumps the heated air when the valve is closed) pointing down, thinking that it would provide better airflow to the lower cowl exit.  This meant that the box had to be up the firewall some amount to allow room for the control cable to exit below it, so it ended up next to the battery.  Hopefully I don’t regret this, but I’ve been pondering it for several weeks and it was time to make a decision and get on with it.  I think in this location, it would be easy to add a flange on the cabin side if desired later, to direct the air from that vent to an eyeball or glareshield vent.  Everyone I talked to who has the muffler exhaust, or has flown a plane with it, is pleased with it and says that there is more than enough heat output, which will be a good thing.

I used a 2″ hole saw (buying the kit of quality hole saws was a good move, as I’ve had zero difficulty cutting the stainless) with the drill motor slowed down (regulator set ~35psi) to make the holes, and used the doubler for a template to drill the mounting holes.  I decided to use #8 screws rather than the #6 called for in the plans, mostly because I had truss-head #8 screws, and only countersunk #6 screws.  And, rather than using nuts on the backside, I put nutplates on the doubler to allow for easier one-man installation and future service.  These are the triangular heat boxes from Robbins Wings, which have a stainless steel hinge and flapper, with an aluminum box.  The theory being that if there was a fire, the box might melt away, but the flapper, being stainless, would remain to cover the 2″ hole in the firewall.  This is a variation on the all-stainless box, and seems good to me.  They include the doublers, and are set up for control cables on the engine side.

With the heat boxes in place, the next order of business was to install the firewall recess.  Besides removing the top skin, this meant mixing up the firewall sealant, Flamemaster CS 1900.  It is a two-part concoction, similar to Proseal, but part A is a very stiff paste and part B a thin liquid; it is difficult to mix, and remains very thick after mixing.  The data sheet indicated that it could be thinned for application, including brushing, by use of ketone solvents.  A little research told me that acetone is a basic ketone solvent (which saved me a trip to the store for MEK), and it took a lot of acetone to get it to a workable consistency.  Put it in a freezer bag for application, same as I did with the Proseal on the fuel tanks.  After wiping all the parts down with solvent as instructed, I ran a bead between the recess and the firewall and clecoed it in place.  I let that begin to set up while I sealed and installed both wiring pass-thrus, and sealed around the brake reservoir penetration.  Then I went back and riveted the recess in place, and sealed around the edges and in the seams and corners, filling the holes at the corners with a blob of sealant.  Cleaned up the mess and called it good.  Once the recess was in and the sealant had tacked, I bolted and torqued the battery box and heater boxes.  No pictures of the sealing process, because it’s hard to use the camera when your hands are covered in black goop.  The copius acetone thinning didn’t seem to affect it’s ability to cure, and it skins over fairly rapidly after dispensing.

Once the sealing was complete and cleaned up, I installed and clamped the outer firesleeve on the wiring passthrus, as it needs to be in place before the wires are run, and I didn’t want to forget it later and have to take all the wires out to install it.  (Like flaring tube without a B-nut, or soldering a connector without the backshell — not that I’ve ever done either of those…)

Engine mount is next…had to fit and remove a couple times to work on the nose gear bolt clearance, and I ended up putting a little “dent” in the firewall behind the gear leg to shift it aft and provide clearance for the bolt & nut.  I’ve read that this is not uncommon.  I also had to file a bit more off of the lower fuel pump nutplate to clear the lower mount tube, and I filled both nutplates with firewall sealant, since I’m not using them (this pump location is used only for carbureted engines; I wasn’t sure whether I would have carb or FI when I built the firewall, so I put the doubler & nutplates in).  As of now, the engine mount is bolted up, but not yet torqued, as I expect to need to remove it (along with the engine) one more time to drill and install all the cable and plumbing penetrations, once I figure out where they need to go.

More futzing with the firewall, getting bits and pieces in place while waiting for engine mounts to arrive.  The “forest of tabs” ground block from B&C arrived yesterday, so that was drilled to the firewall today.  I added an extra bolt at the end of the aft piece, to guard against any vibrations…installed a nutplate for it on the aft side, so the bolt on the fwd side could be used for an adel clamp or whatever if needed in the future.

Re-fit the fuse holders to the firewall and made up the copper bars that connect the two fuses, plus the bar that feeds the switched side of the battery contactor to the fuses, and the lug that will connect the battery cable to the contactor.  Once the copper bars were fit and drilled, I used some heatshrink tube to cover all but the ends, and notched the covers of the fuse holders to fit over the bars.

That done, I decided to fit the backrests and drill the seat hinges.  The install guide makes this seem a bigger deal than it actually was, and they went in pretty quick and easy.  I used the hinges I had made up during the fuselage build.  I may have to re-do the right side later with a new piece of hinge (Classic Aero includes hinge pieces, so I have spares), depending on how tight the canopy frame is to the seatback.

Also mixed up some proseal and glued the stainless screens to the fuel vent fittings.

Finished up the fitting of the right flap with a couple off-on cycles of the flap pushrod to get the exit hole just right.  Momentarily hooked up both flaps to actuate them and see if they had correct travel and both retracted flush at the same point.  All seems to be well, though the total travel is about half a degree short of 32* — the spec called out is 32-37.  I’ll have to check what others have had, but I don’t really see a way to increase the travel–changing the pushrod length seems like it would change the up and down points, while leaving total travel unchanged.

After that was completed, the flaps were removed again, and the wings removed and placed back in the cradle.  Flaps and ailerons were put back on for storage–it’s easy to store them there, where they’re less likely to suffer accidental shop damage.  Fuselage and work table pushed to opposite sides of the shop to make room for Allison’s car in the middle.  It’s not by any means a usable shop to accomplish work in, but hopefully will help keep her happy in the mornings.  When the engine arrives, it may need to go in the living room, though…