Antennas (2)

 2 hours

Today I installed three of the four antennas I'm going to use:

Garmin GA 35 for the GPS

Comant CI 105 for the transponder

and the ACK antenna that came with my E-04 ELT

The fourth antenna will be a Comant CI 122 for the VHF radio, but I'm not exactly sure where I'm going to put that one yet.

The GPS antenna was the only one that really took much custom work, but it wasn't too bad.  I located it on the turtledeck just behind the canopy.  Since the two sheets that form the turtledeck overlap right there at the top, it created a non-level surface.  I added a small doubler to the right side so the antenna could have a flat surface to sit on.  I also drilled out five rivets and replaced them with flush rivets.  I guess it's not really flat, because it's obviously curved, but you know what I mean.  I bought a piece of 1/8" thick rubber sheet from Lowe's to make a gasket, and that sort of worked to close the gap between the antenna base and the top of the plane.  I think I will find a slightly softer piece of rubber and redo this later.  If the gasket compresses a little more I think this will work okay!

I don't have any good pictures of it, but I installed the transponder antenna on the floor just aft of the baggage compartment.

I put the ELT antenna on the turtledeck right above the control mixer.  That allowed me to reach up through the mixer access panel to reach the connector on the inside.  One note I have is, if you install the antenna close to centerline like I did, the connector will be real close to the C-channel that runs down the spine of the turtledeck on the inside.  I was able to make it fit by using a 90-degree adapter, but it would have been a little easier to just drill the hole slightly farther off-center!

Flap Position Sensor (2.5)

 2.5 hours

While shopping for other electrical parts and stuff, I realized I could add a little position sensor to my flap actuator, and wire it right into the G3X system so it would display the flap position on the PFD.  The sensor is a Ray Allen POS-12.

This took a little figuring out but in the end it ended up pretty simple.  I picked a spot on the right side vertical channel, just in front of the actuator, to mount it.  I used a little piece of scrap C-channel cut in half so it's just a small piece of angle pretty much.  That got riveted to the side member, and I screwed the sensor to the bracket.  

For the pushrod, I just picked up a 12-inch "Kwik-Link" rod from an RC hobby shop (I also picked up a couple M3 screws there too to mount the sensor).  One end has a little adjustable plastic connector thing, and the other end is just plain rod.  The plastic connector actually fit perfectly in the sensor.  Once I figured out the length I needed, I bent the plain end into a hook shape and cut off the excess.  Then I just ziptied the hook end to the arm on the flap tube.

Here's how it looks all hooked up:

I ran a 3-conductor wire from the sensor the GEA 24 box on the inside of the firewall.  Once I had the wires hooked up, it was super easy to set up and calibrate on the G3X display.  Here's all I had to do to get it working:

Finally, here's how it looks on the PFD screen!

Transponder Installation (6)

 6 hours

The last Garmin component I finally bought was the transponder.  I couldn't really decide if I wanted to get a GTX 45R, which does ADSB in and out, or the cheaper GTX 35R that does ADSB-out only, and add a GDL 50 later for ADSB-in.  I was leaning toward the 35R, since it plus the GDL 50 was still cheaper than the 45R, and having the GDL connected to an iPad would give me a simple backup navigation system in case of aircraft electrical failure (since the GDL and iPad each have their own battery).

I stumbled on an open-box but never installed GTX 35R on ebay a while ago for about $700 cheaper than MSRP, and that's what finally did it for me!

Anyway, this transponder is made to be installed in an avionics rack, which I don't have.  It slides into this little bracket conveniently, I just needed to figure out how to mount the bracket in the plane.  After a little head-scratching, I ended up just making some little brackets to attach the mounting bracket to the side skin in the baggage compartment (opposite the radio and GPS).  There's not enough space to be able to slide the transponder out of the bracket, but if I ever need to remove it, it'll be easy enough to undo the screws that go through these brackets.

Next I ran the wires.  I just continued my wire bundle from the right side of the baggage area, along the floor just behind the seat, and up the left side to the transponder.  It's not on the CAN bus, so all it needed was power, ground, and RS-232 connections to the ADAHRS and the GPS.

More Wiring (8)

8 hours

More wiring!  This was mostly a few annnunciator LEDs on the panel, and all the audio connections to and from the radio (2x headset and mic jacks, stereo in from a 3.5mm jack on the panel for music, and mono in from the display for alerts).  I now have all the Garmin stuff that's installed so far just about done!

I put the headset/mic jacks on the first turtledeck former, which made for a real short run for these cables!

Magnetometer (2)

2 hours

I delayed installing the Garmin magnetometer (GMU 11) until I had pretty much everything else connected.  The G3X manual has a bunch of requirements for how far the magnetometer should be from other electrical devices and magnetic (i.e. steel) objects.  In a plane as small as this it's probably not really feasible to meet all the requirements exactly, so I connected the GMU to a long wire and tested it in a bunch of possible locations.  I was surprised to find that just setting it on top of the beam at the back of the baggage compartment produced the least magnetic interference.  Placing the GMU farther aft than that was closer to the control mixer, and what I found was moving the controls produced way more interference than the other electrical stuff I had in the baggage area (flap motor, radio, etc.).

So anyway I made a simple mounting bracket out of a piece of 1.5" x 1/16" angle, and riveted that to the beam behind the baggage area.

This location also made for a short and easy wire run from the GPS box.  The GMU is the last item on the CAN bus!

Hours Breakdown #6

I haven't done a tally since January, so here's where I'm at.  I don't even want to know how much time I've spent scratching my head and designing/planning the electrical and avionics stuff!  This tally only includes physically working on the plane.

Anyway:

General/Misc:                     16.0
Tail:                                     72.0
Wings:                               153.5
Control Surfaces:                59.5
Fuselage:                            203
Controls:                              46
Landing Gear:                     14.5
Windshield/Canopy:            46.5
Cockpit/Panel:                     23

Engine/Firewall Forward:    92

Cowl:                                   20.5

Electrical/Avionics:              48

Total: 794.5 hours

I've read that 1000 hours is pretty typical so I guess I'm getting there!

Garmin Wiring (24)

 24 hours (so far)

This is a project!  I've spent that last two weeks or so just stringing wires between all the Garmin components.  I'd guess that I'm probably about two-thirds done now.  It was sort of slow going at first because I had to figure out where to route all the wires, but once I had a path kind of laid out it was just a matter of adding more and more wires to the existing bundle, and connecting them to wherever they needed to go.

My goal for wire routing is to keep everything out of sight or at least totally out of the way of occupants and any moving objects (flight controls, etc.), and to avoid running wires through any holes that the whole bundle and connectors wouldn't fit through (so if I ever have to change anything I can pull the wires out without having to cut big chunks of the harness apart).

I am not counting the hours it took me to map out the Garmin wiring diagram for my system, but I have spent a lot of time on it!  I think I've been chipping away at figuring this all out since like April, and I'm still adjusting my diagram here and there as I install things and find issues with what I had planned.  Anyway here's the latest version of my Garmin diagram (you might have to click the image to enlarge it and then save it to zoom in... it's big):

I don't really have too many pictures of just running wires, but I'm not done yet so I'll try to capture everything once it's all installed.  However, here are a few tidbits I thought were worth taking pictures of:

First, I have two buttons on the stick: push-to-talk for the pilot, and an autopilot disconnect.  The PTT connects to the radio and the A/P disconnect connects to both autopilot servos.  Both are normally open and switch to ground.  Anyway I'm using the AeroConversions stick grip which has spots for two buttons, and I got the buttons from Aircraft Spruce.  I drilled a hole and installed a rubber grommet in the side of the steel tube part of the stick, and fished all the wires through there, and then soldered them to the buttons.  I ran all the wires to the right, and terminated the ground wires with a screw through one of the seat support ribs.  The other two wires went off to join the rest of the wire bundle towards the servos and radio.  Really the only tricky part was figuring out where to ziptie the wires to the stick in a way that they couldn't get stuck or wrapped around anything through the full range of motion!

I also shortened the stick by about 1.75" to clear my extended panel.

Black is PTT and red is A/P Disconnect

Next, I installed the Garmin outside air temp probe (GTP 59), just behind where I put the ADAHRS, which is what the probe is wired to.  This made for a short wire run!

This is all the wire I needed to connect the OAT probe.  It came with a 10' lead so that was just free wire!

OAT probe location.  The four screws just forward of it are the ADAHRS.

Finally, although I'm connecting just about every ground wire to the grounding block on the firewall, I found that it was pretty easy to ground certain momentary switches to the switch itself.  Here's a pushbutton I have on the panel that engages the autopilot when grounded.  Seems like the easiest way to do it if you have a ring terminal the same size as the switch body (this one is 1/4")!

Engine Sensor Wiring (10)

 10 hours

Once I pretty much had the firewall forward wiring figured out, I figured I should do all the engine sensors next.  That way I'd have pretty much everything that penetrates the firewall done.  Here's a list of all the engine sensors feeding into the GEA 24 (engine interface box):

CHT Thermocouples x4

EGT Thermocouples x4

Turbo Temp Thermocouple

Oil Temp

Oil Pressure

Manifold Pressure

Fuel Flow

Fuel Level

Ammeter

RPM

It doesn't really seem like a whole lot but it adds up to a lot of wires!  By far the most time consuming of these was all the thermocouples.  Each thermocouple has two wires, each with fiberglass insulation, and then the pair is also covered in more fiberglass insulation.  Wire strippers don't really work on the fiberglass, so for each wire I had to manual pick the fiberglass apart and snip it off to expose the ends to connect.  On top of that, 7 out of the 9 thermocouples had to be extended to reach the GEA 24, so I had to pick up some extra thermocouple wire and some special connectors.  30 feet of extra wire ended up being the right amount; it was plenty and I didn't have a whole lot left over.  Here are links to the wire and connectors I bought:

Thermocouple Wire

OLC-2 Connectors

The CHT and EGT thermocouples all went to one of the four connectors on the GEA, so I was able to assemble that connector and call it done.

The next connector includes RPM, the turbo temp thermocouple, ammeter, oil temp, fuel flow, and the oil and manifold pressures.  All of these, except the thermocouple, require shielded wire with the shield grounded to the connnector backshell.  I had no idea what any of that meant until I studied the G3X manual quite a bit and found this video from Garmin that shows how to solder the shields: https://www.youtube.com/watch?v=jmVLVhGoGQs

Actually, this playlist pretty much covered all the soldering and connecting methods that I needed to learn, so that was super useful:  https://www.youtube.com/playlist?list=PLTucYQ1EkW8f7bXkGRWvb2OEE80BFRMTF

Anyway, after doing it a couple times the shields were pretty easy to deal with.  The oil and manifold pressure sensors, and fuel flow sensor, all came with 3-wire pigtails that I extended with 3-wire shielded wire to connect to the GEA 24.  The ammeter, oil temp, and RPM wires I just made from scratch.

I soldered in some tiny 1A fuses to the ammeter shunt wires