Here’s a picture
Here’s another picture
And another picture
The tailcone avionics and electrical wiring are done and I really want to rivet the fuselage “turtledeck” skin – the one behind the cockpit. But I also don’t want to dive back there to fix wiring problems once it’s in place.
I’ve smoke-checked the ELT’s RS-232 data connection to the GTN-650, the tail nav/strobe light and even the elevator trim servo. But the last bit to be checked is the servo’s position indicator and the only way to know for sure is to configure the G3x Touch display to read and display position indicator signals. So that’s what I did.
Configuring the Touch was a lot easier than I feared. All that’s required is to move the trim servo to full up, center, and full down and tell the display when the servo is positioned at each point.
The Touch calibration page reads voltage coming from the position indicator and displays a gauge preview…very cool. That’s a good confirmation that the tailcone wiring is fully functional.
And now Elevator Trim shows on the PFD…even more cool!
A few more minutes and the turtledeck is clecoed into place for the last time and we’re ready to break out the rivet gun and bucking bars.
One of the cool things about this stage of the project is that after a few hours of wiring I can turn on some part of the RV’s avionics and see it work.
For instance, I’ve had these Oplite 6 LED lights for several years now and finally got them wired up to the Garmin GAD-27 as instrument panel lights, so they’re controllable by a dimmer on the panel. These lights are really rugged and when driven by one of the GAD-27’s PWM lighting controllers, they’re dead quiet too – no hash on the radio like I’ve encountered with some other dimmers. Very cool.
I’ve also had Whelen LED nav/strobe lights sitting around for a few years, waiting for installation. The tail nav/strobe is finally wired through to the cockpit, and here’s some video to show how damn bright they are…low current draw too, and no need for a heavy strobe pack like older nav/strobe lighting systems.
Next on the list was wiring the flap motor, but I need some hardware to fabricate a mounting bracket. So, I jumped ahead to wiring the Advanced Flight Systems Angle-of-Attack (AoA) system. This is the only “legacy” avionics system on the airplane, as Advanced doesn’t sell it anymore. I hope it doesn’t fail.
For those of you who aren’t into aerodynamics, AoA is the angle at which the wing meets oncoming air, thus generating lift. If AoA exceeds a certain value, the wing stalls and lift is drastically reduced – so you can see why knowing AoA might be important for staying in the air. If you’re really into the concept, watch this video.
Everything lights up, and the self-test lady says the system is working…
Of course with all the gee-whiz stuff lit up, I had to take a picture. Enjoy!
I’ve been checking off some smaller tasks from my to-do list, one of which is figuring out where to mount the Pilot and Co-Pilot headset jacks. I didn’t want them hanging from the panel, so I put them on the cover plates in front of the wing spar bulkhead.
These covers are sold by Aircraft Spruce, and they worked really well.
Sometimes all those little individual tasks you’re churning on, come together in a moment of progress. Tonight was one of those nights – the battery contactor and avionics relay switches are now active, and the main and avionics busses are connected. It’s time to flip a few switches…
Lots more wiring to do, but motivation is high.
Even more fun with wiring…working my way forward from the tail I routed serial data and power wires to the ELT and assembled the autopilot pitch servo DSub connector.
I also ran coax to the GTN-650 GPS and G3x GPS/XM antennae.
Assembling coax connectors is fun, at least for me…
More to follow as I work my way forward to the cockpit.
There isn’t a super-convenient way to route pitch trim and magnetometer wires into the empennage, so I improvised…
Here’s the pitch trim servo wire exiting through a lightening hole in the fuse rear deck.
I liberally applied adhesive zip-tie mounts to the rear deck and glued a small piece of aluminum angle to the rear spar with 3M 4000 marine cement (easier than riveting) to hold another zip tie.
The black material is self-closing anti-chafe wire bundling I found at McMaster-Carr. The plans call for running trim wires along the front of the left elevator and into the trim servo bay. I think this is better than running wire through the existing manual trim cable holes as repeated elevator movement over time slightly twists the cable rather than bending it – much better from a wire fatigue/failure perspective.
You’ll see in this picture how the trim servo cable is routed into the left elevator and why some support is necessary where the cable crosses the HS rear spar.
And here’s the wired trim servo ready to be stuffed into the elevator. It’s slightly tricky to route the cable so it doesn’t interfere with the servo’s jack screw, but I think I’ve managed to get everything done correctly.
Back from Thanksgiving with family at Bear Ass Cove on Newfound Lake, New Hampshire and guess what UPS delivered? That’s right – the avionics harness!
I’m almost ready to install the harness – just a couple of empennage things left to finish – but I couldn’t resist stretching it out. This is, essentially, the Mighty RV’s nervous system and having it fabricated by the neurosurgeons at Approach Fast Stack is saving me a *ton* of build time. Cool!
Finally getting a lot of little cleanup tasks done while the avionics harness is percolating at Approach FastStack.
First, I installed this…
First person to guess what it is gets a ThermosWorks sticker or a free beer at Oshkosh 2019.
Second, I dug out the cockpit lights from Oplite and fabricated a small bracket to mount them on the roll bar support.
These lights are extremely well-made by my friend and fellow RV builder Rich Mileika. In addition to Oplite, Rich owns and operates Machine, Inc, a precision machining company in the greater Boston area. If you need quality cockpit lighting, try Oplite…you’ll like ’em.
And lastly, I replaced the stock Van’s flap motor with an upgraded version made by Pat Hatch at PH Aviation Services.
This motor has several advantages over the stock unit. The motor and jackscrew are separate so grease can’t migrate into the motor windings, a common problem with the Vans motor. It also has limit switches to stop the motor at full extension on either end, and also has a position sensor to report flap position to whatever device needs it.
The only downside is that the flap support bracket must be modified to accommodate the new motor. Rather than trying to rework the existing bracket, I bought new parts from Vans and started from scratch…only took a couple of hours, and Pat’s motor will save some wiring work later on.
I think it’s time to start mounting stuff in the panel. Being an electronics/avionics geek, I’ve waited for this for a long, long time.
The G3x GSU 25 ADAHRS is mounted on the subpanel behind the PFD/MFD – makes plumbing the pitot-static lines to the GSU and G5 a little easier. It was hard to get in there with a ruler to lay out hole positions so I made a drill template out of thin Al.
One minor hiccup…the ignition switch locking tab isn’t clocked correctly, causing interference between the switch body and panel support rib. I’ll probably have to grind off the tab and rivet on a new one at the right orientation. The switch label will cover the rivets nicely.