Joshua's RV-9A Project

Just a bit of time in the shop after working 9 hours during the day on other things…what vacation?  Riveted in the panel brace, reinstalled EFIS 1 and connected the AOA tubing, mounted the ELT bracket, and clipped some wireties from a previous session, along with the usual staring at the project to see what’s next.

Spent a good portion of time in the shop today, but didn’t accomplish a great deal, it seems.  I started the day with a list of what seemed like easy quick tasks, but in reality, I only checked off one thing.

The main order of business for the day was finishing the EGT/CHT wiring FWF.  Having installed or test-fit essentially everything in the area, I finished running the wire harness and sorted out which wire was which.  After creating service loops and trimming to length, the wires needed to be terminated, using the recommended method (crimp, flux, solder, heatshrink) from AFS.  I put heatshrink on each terminal, as they’re uninsulated; once the terminals were joined together, heatshrink went over that, then a larger piece of heatshrink to bundle the pair of wires for each probe together.  It should be secure and well-protected, yet still easy enough to cut away when a probe needs to be replaced.  Once everything was hooked up, I used a heat gun to check that the proper probe is wired to the proper location — the EGT’s are, but I wasn’t able to get the CHT’s to show on the display; not sure what’s going on there, although the EGT’s disappear below a certain point as well (100*, I think), so the CHT’s probably have similar logic and I just wasn’t able to heat them far enough given the larger thermal mass of the cylinders.

Other more minor tasks accomplished:

• Fabricated, fit, and painted an angle brace to go between the panel and the subpanel, to eliminate a slight flex in the left side of the panel.  The brace ties into the EFIS 2 tray with a countersunk screw, and is fixed to the subpanel with a riveted clip.  Will install this tomorrow once the paint is dry.
• Installed the ELT remote to the panel, and attached the audio alert box to the subpanel.  The audio alert can be serviced without removal, since the cover unscrews from the base, but the remote will need to be removed again for installation of the battery.  There are actually three batteries in the ELT system — one in the ELT itself, one in the remote, and another in the audio alert box.  All except the ELT have to be procured by the builder.  I haven’t looked yet to see if they’re all good for 5 years like the ELT battery, or if more frequent replacement is required.
• Since EFIS 1 was removed for access to fit the panel brace, I took the opportunity to enlarge the wiring hole behind it.  My initial hole was large enough for the requisite wires, but the bigger, oblong hole will remove the tight bend that a few of the wires had to take, and give more space for the pitot/static/AOA tubing.  Speaking of which, I found that I never ordered the fittings for the pitot/static connections to the EFIS.
• Ran switched/dimmed power and ground to a plug at the subpanel, where the panel flood lights will connect.  These lights are mounted to the underside of the glareshield, which is part of the canopy, hence the need for a disconnect to allow canopy removal.

Now that work has settled down for the summer (127 hours in the last two weeks…), I’m trying to get back into the swing of working in the shop.  Took the day off work and bounced around on a few little things…

• Finished drilling the hinges to the cowling and clecoed in place; test-fit the cowl and spinner backplate.
• Fabricated a mounting tray for the AFS magnetometers, one bulkhead behind the baggage wall.  Installed the D-sub connectors and tested that the EFIS was talking to the magnetometer, which it was.  Clecoed everything in place for now; will need to rivet the tray in place, and pick up some brass screws for mounting the sensor itself.
• Temporarily put in the lower spark plugs and attached the plug wires, so I could see where clearance would be needed in order to…
• Drilled and installed the EGT probes to the exhaust pipes.  Fit the mufflers to the crossover pipes and held them up with bungees for now.
• Removed the too-short mixture cable and replaced it with the new, longer one (48″) that arrived.  Fabricated a new bracket to secure the cabin ends of the control cables, and adjusted the linkages for proper throw on the quadrant and the fuel servo.
• Started work on the rear left engine baffle where the oil cooler attaches.  Fabricated a reinforcing angle for the baffle corner to avert vibration cracking, and a thicker doubler plate for the cooler itself.  Once the cooler was located on the baffle, trimmed away a portion of the aft flange on the cooler to provide clearance from the engine mount tube.
• Remade the fuel pump mount piece to accommodate the new version of the Andair fuel pump, which mounts a bit differently due to the now-integrated controller design.  The new mount is actually simpler; the overall pump length appears to be the same, so no adjustment of fuel lines will be needed.

It was interesting to me that two things appeared in the last couple days that found me where I’m at: an article in EAA’s homebuilding e-newsletter, and parts of a thread on VAF, both around with what the article named “Project Paralysis.”  It must be the weather–for most of the month, it’s been gray, gloomy, raining/snowing, and cold (running 10+ degrees below average; we had snow yesterday for a bit).  March was exciting, and I put in far more hours than expected (nearly 80), but April has been a downer.  Only 25 hours, and the motivation to head to the shop in the evenings hasn’t really been there.  Work is heading into the busy spring season, which will last the next 5+ weeks, but I don’t think it carries the sole blame for the lack of energy.  Must be the weather…here’s hoping the snow stops soon.  On the bright side, I’ve spent some good time with Allison talking/dreaming/scheming about plans for the summer and beyond.

This week, though, has been looking up.  Lots of boxes arriving, the UPS man has been here every morning.  Engine hoses, control cables, and my AFS screen are here, and the Vetterman exhaust should be in tomorrow.  I’ve been reading up on fitting the cowl (among others, a good thread by Brantel on fitting the pink cowl, and a new one on baffles, plus DanH’s highly informative and well-illustrated fiberglass tips), which seems like a logical next step.  I need to pick up or dig up some PVC pipe to use as a stand-in for the prop spacer, and fit the camloc strips first.

The task list for tonight was simple, and easy to motivate with new and exciting parts: test-fit the hoses, and fire up the EFIS.  All the engine hoses seem to fit well (though the oil cooler is not yet installed, so those can’t be fit yet).  I got these from Tom at TS Flightlines, who was easy to work with and fast getting them out.

The EFIS screen (AFS 4500-EE), having already wired all the harnesses during the panel install, slid right into the tray and powered up.  Spent some time going through the menus, configuring serial ports and such.  Two oddities I noticed (1. the master warn light never illuminated when it should, but did when the screen was powered off, and 2. the screen always powered on when the master was turned on, even though the avionics bus wasn’t on), turned out to be related, and a simple fix: I had inadvertantly inserted the pin for the master warn light into the wrong hole, which caused it to be hooked up to the backup power input.  It was getting power on that backup input when the master went on (since the annunciator power is always on), and booting up (and illuminating the light).  Once primary power was applied, it stopped using that backup input, and the light went out.  Moving it to the correct pin solved both problems.

Allison came out and I put her seat in, and we sat in the plane looking at the panel.  Tested that the audio out of the AFS works, and it talks to everything hooked to it: VP-X control, transponder gets altitude, a finger in the CO detector pops up a readout of O2 saturation and heartrate, and it sees data from the GPS.  I posted a message on the AFS forum about the volt and amps gages…I had been under the impression they would take their readings from the VP-X datafeed, but that doesn’t seem to be the case, or at least I can’t find it in the menus.  The voltmeter is using the internal sensor of the AFS (not a big deal, it matches the VP-X within 0.1 volt, but of course reads 0 when the avionics master is off), and the ammeter just reads 0, since I didn’t install the shunt (since I thought it would come from the VP-X).  Both values are displayed on the VP status page, but it would be nice to have them as gages in the display, and be able to alert on them.

Did a couple more odds and ends that needed doing, including some fun contortions to work in the baggage and tailcone areas:

• Installed the DB-9 connector for the autopilot pitch servo
• Installed new nutserts to secure the seat heater relays in their new positions
• Torque seal on the fuel flow transducer bolts
• Installed nutplates for the aux alternator relay and capacitor
• Placed the N-number placard on the panel

Also refit the canopy and forward top skin in order to look at a few things up there:

• Attached wire to and nstalled the strip of LED’s that will be the panel floodlights.  Temporarily connected to the switch to test; still need to run those wires for real and put a connector behind the panel.
• Checked again for clearance between the outer top corner of the EFIS and the panel reinforcement; looks like it should be fine, as planned.
• Checked for catching of the canopy skin when opening; looks ok after filing off a bit more from the forward edge.
• Found where the canopy frame is rubbing on the side seal support angles (which weren’t yet installed when the canopy was previously fit).  Those will need to be filed down for clearance.

Spent most of the shop time tonight just standing, staring at the project, trying to divine the way forward.  Did manage to accomplish a few things:

Installed the fittings on the fuel flow sensor, and installed the fuel flow sensor to the mounting plate with 1/4″ bolts and torqued.  (Note to self: put torque seal on fittings)

Located a spot to mount the relay and capacitor for the SD-8 backup alternator…of course, the adel clamp necessary to mount the cap appears to be a -22, which is the one even size I don’t have on hand.

Moved the seat heater relays forward in the tunnel, and rerouted the wiring harnesses.  This change was necessary because I discovered after putting the seat cushions in, that the wire from the seat bottom wasn’t long enough to allow for the movement that happens when the seatback is tipped forward (such as loading baggage), without unplugging it.  So, I brought the relays forward as far as practicable, which let more wire stick out of the tunnel.  I still need to re-do the mounting of the relays; they’re ziptied to the tie base that was previously holding the cables, but I’m not satisfied with that, since this is in close proximity to a flight control (elevator pushrod).  I’ll probably put in another rivnut as I did in the earlier location–could also pop-rivet them down, but relays are mechanical and will fail, requiring removal for service.

My APRS transmitter from Byonics arrived today (along with an oil cooler and spark plugs from Spruce), so I thought that would be a simple and satisfying installation.  First, I opened up the tracker and wired a short piece of 22-3 to the internal LED, bringing it out through a small hole in the case.  A 3-pin Molex went on the end–this is to drive a bicolor LED like the one built into the tracker, but external, since I will have the tracker mounted behind the baggage bulkhead.  Having installed a TinyTrak in my car, I know it’s handy to have the status lights to see what the tracker is doing.  With the external LED plug wired, I closed the case back up and proceeded with the installation on the plane.

I put a pair of small holes in the baggage bulkhead, far enough to the side that they won’t interfere with the corrugated wall panel.  The top hole received the bicolor LED; it indicates green for GPS status (flashing means it’s receiving data, solid indicates a valid fix), and red to indicate it is transmitting a position packet.  The lower hole is occupied by a 3.5mm TRS jack, similar to the ones I’ve used in several other places for RS-232 service ports.  This one is a bit different, since the other (Pmags and ADS-B) are dedicated serial ports on the devices, whereas the tracker also receives its GPS signal via this port.  So, a normalling jack is used here — when there is no plug inserted, the GPS signal is fed to the tracker.  Inserting a plug breaks the GPS connection, and connects the tracker’s input and output to the computer.

I could have put the LED on the panel, but a) it’s not at all a critical item, b) the flashing light could be distracting, especially at night, c) that would require another wire through the spar, and d) it’s still readily visible by looking over my shoulder.  Both the LED and the port are easily accessible for servicing the tracker and checking it’s operation, while being completely out of the way.

Wired the tracker to power, too, and enabled that pin on the VP-X.  Terminated the coax from the NMO mount with an SMA connector, hooked that up and flipped the switch.  The tracker booted right up, so I powered the GPS and got a solid green light.  Good to go.  The service port is functional, and I programmed the tracker config and grabbed my handheld scanner to verify that it is transmitting.  None of the packets hit the internet, which doesn’t surprise me at all since it’s on the bottom of the fuselage (which makes sense in the air), and inside the shop.

Long week with no work on the project; the busy season has begun at the office.  Some positive news on the financial picture front this week though, so I at least ordered a bunch of pieces that I’ve been holding off on, for upcoming installation (lights, exhaust, APRS stuff, ELT, oil cooler, etc).

Got a few things done and half-done today; starting off with the wiring for the pitot indicator.  I bought my Gretz pitot secondhand, and it didn’t include the indicator board, since the previous owner had installed it in his plane.  No problem, it’s just a few LED’s with appropriate resistors, but I hadn’t yet taken the time to measure the voltage, find the right resistors, and build the board.  I used a chunk from a leftover piece of prototyping board, trimmed to fit the necessary components.  I also put a 4-pin Molex connector on it, for ease of connection (the soldering could happen on the bench, rather than in the plane) and service.  A matching connector on the wire behind the panel, and we’re in business.  I connected up the pitot for testing, and rolled the wing cart over to plug into the fuselage.  Power on, and everything looks good: the lights indicate as they should, the heater cycles, and the tube tip gets hot.  While I had the left wing hooked up, I checked the function of the leading edge light and made some minor programming changes in the VP-X (renaming some pins).

Installed a standard NMO mount and the Antenex Phantom Elite antenna I ordered, which will be for the APRS installation.  I also ordered the new MicroTrak RTG FA from Byonics, which should arrive next week.  The antenna is mounted halfway between the comm antennas and the transponder antenna.  I could have mounted it aft of the transponder antenna instead, but since the VOR/Loc antenna location is at the tail end, I thought it better to keep the APRS more distant, since the APRS and Nav signals are on nearby frequencies, while the transponder is removed by several hundred MHz.

Thanks to some photos helpfully posted on a VAF thread, I decided to figure out the installation of the fuel flow sensor.  I fabricated a mounting plate from some scrap .125 bar stock, which attaches to a pair of engine mount tubes via Adel clamps.  The sensor mounts to the plate using it’s own 1/4″ mounting holes, for which I of course don’t have the correct length bolt (AN4-17A).  I also need to order the steel nipples for the in and out of the sensor; the sensor ports are 1/4″ NPT, rather than the 1/8″ commonly associated with the -4 fluid lines, so that will require the “-4-4″ nipple, which is 1/4″ NPT to -4 flare.  I cut off the spade terminals on the sensor wires and fit a 3-pin Molex instead, then ran the harness wires to the sensor location and connected the two.  I also installed Adel clamps to strain-relief the wires both at the sensor and at the connector.  Since the mounting plate floats in space between the two engine mount tubes, it’ll be possible to wrap the entire assembly in a piece of firesleeve.

With the FF sensor located, I set about measuring for fuel lines, and re-checked all the ones I’d measured previously.  I have a list of 8 hoses that need to be made up now.  There are two more yet to be measured, for the oil cooler lines, which won’t be evident until the oil cooler arrives and is at least mocked up in place.  Plus, the brake lines, but at least those are already known lengths.  The steel oil cooler fittings will also need to be ordered.

Moving back inside, I experimented with various locations for the pitot/static manifolds.  Fabricated a bracket to mount both, one atop the other, and mounted it to the subpanel.  I need to pick up some longer #6 screws to mount the manifolds to the bracket, though.  Trimmed and inserted the pitot and static lines, and a pair of jumpers for EFIS 1.

Also spent time cleaning the shop, tossing/recycling the large pile of debris that had collected under the plane.  Storm season is here, and I need to get at least one vehicle inside when weather threatens (as it is this weekend).  I figured out that I can move the fuselage 90 degrees to the right and Allison’s car will tuck nicely under the tail.

Passed 1300 hours in this session.

More wrapup of loose ends in the cabin area, mostly dealing with the last of the electrical:

• Installed the DB-37 connector shell and hood for the ADS-B, and tied up that bundle.
• Installed the hood on the ARINC module connector.
• Soldered the 3.5mm jack on the ADS-B maintenance port connector, enlarged a tooling hole in the subpanel, and installed the jack there.
• Fabricated engine ground cables and installed between the firewall ground buss and the engine case.
• Measured for throttle and mixture control cables.
• Cut and installed the ducting between the vent scoops and the panel vents.  (Need to get some screen mesh to put on the vent scoop end to prevent ingress of bugs.)
• Removed the parking brake cable from its mount, so that the mount could be removed and painted.  Realized that the ball bearing fell out of the cable mechanism; spent some time searching for it in vain.  (Hint to similarly troubled souls: ACS sells replacement balls for $2 apiece; a bag of 50 is under $5 at McMaster, and then you can lose it 49 more times.)
• Swapped out all the screws on DB connectors for thumbscrews…much easier to work with, especially upside down under the panel.
• Installed a snap bushing in the left subpanel rib for the pitot and AOA lines to pass through.  Ran those lines up the left vertical FW stiffener and tied in place.
• Tidied and tied up the bundles of wire in the tunnel.
• Cut pieces of vinyl tubing to slip over the tubing in the tunnel for anti-chafing at tiedown points.  With much contortion, tied up the fuel and brake lines in the tunnel.  Still a couple to do, and one tiewrap base where the glue is obstructing the hole; it may be possible to open it up with some safety wire.

The day’s other task was attempting a redo of the nosewheel bearing.  When I installed the wheel before hanging the engine, I noted that the rotation was quite stiff.  I have the Matco axle which was supposedly designed in part to alleviate that problem.  It’s very stiff…one theory was that I didn’t manage to properly grease the bearings (they are tricky to hand-pack with the molded rubber seal).  So I bought a bearing packer cup, which did a fine job of packing it; grease squeezes out under the seal.  Re-installed, and no change.  If I tighten down the ring on the axle that’s supposed to set the preload (the instructions say to tighten it until the bearing face does not rotate with the wheel), the wheel requires what seems to me to be a lot of force to rotate.  Given the discussion around the nosewheel issues, this doesn’t seem right.  The bearing cones feel fine on inspection, too.  Anyone out there with experience installing the Matco axle that can confirm or point out where I went wrong?  For now, put it back together, knowing at least that it is well-lubricated.

Made up the service cable tonight; a DB-9 to connect to a PC on one end, and a 3.5mm plug on the other.  I’m installing several 3.5mm jacks throughout the plane as places to tap into serial lines for programming and service:

• Left Pmag (connects to control port)
• Right Pmag (control port)
• NavWorx ADS-B (maintenance port)
• APRS transmitter (normalling jack; interrupts GPS signal for programming)

I headed to the shop to test the cable, and soon discovered that I had wired the jack for the left Pmag backwards; TxD was RxD and vice versa.  Swapped that with the soldering iron, and I was able to connect with both Pmags.

Also verified that the GPS was sending its data out, as I wasn’t able to get it to display on the transponder the other night.  It’s definitely outputting, so some more research on the GTX 327 had inconclusive results as to whether or not the box would take NMEA.  It’s supposed to work for sure with Aviation format, as output by the GNS430 (and presumably the new GTN series), to which it’s wired.  I had planned to run NMEA into those pins from a mating connector, which would feed the transponder and autopilot, but now I’m not sure if it’s necessary, assuming the transponder has no use for it.  I suppose the autopilot can still read it, if I buy that before the GNS/GTN.