GTN650 G3X wiring

I spent a good hour and a half today trying to figure out how to get the GTN650, GTX45R, and the PFD talking to each other. Finally after getting most of the way there I realized that I was searching the G3X install manual for ARNIC and not ARINC. Towards the end of the G3X installation manual in the interconnect section the proper software settings for both the GDU and the GTN. (that is a lot easier than trying to figure that out by guessing the difference between "format 1" and "format 2").

*Note: to get into the configuration sections of the devices, hold "menu" when booting the GDU and hold "home" when booting the GTN.

RS-232 Configuration Overview

• PFD
• RS232-0: GSU25#1
• GSU25#1: RS232
• Configuration: N/A
• RS232-1: GTN650 
• GTN650: RS232-1
• Configuration: MAPMX
• RS232-2: GTN650
• GTN650: RS232-2
• Configuration: CONNEXT
• RS232-3: GDL51R
• GDL51R: RS232-2
• Configuration: CONNEXT
• RS232-4:
• Not Used
• RS232-5: GTX45R
• GTX45R: RS232-3
• Configuration: CONNEXT
• MFD
• RS232-1:
• RS232-2: GDL51R
• GDL51R: RS232-1
• Configuration: CONNEXT
• RS232-3: Vertical Power
• Vertical Power: RS232
• Configuration: "vertical power"
• RS232-4: GEA24
• GEA24: RS232
• Configuration
• RS232-5: GTX45R
• GTX45R: RS232-3
• Configuration: CONNEXT

The following sections detail the software settings for each of the devices.

Vertical Power (VPX-Pro)

1. On the PFD (GDU 4XX) in configuration mode
1. Under RS-232 page in the setup, set the MFD serial port that is connected to the VP-X Pro to “Vertical Power”. (A green check mark in the left column indicates it is receiving data from the VP-X. )
2. The trim and flaps are automatically configured to read their position from the VP-X. If you have a third trim axis wired into the G3X analog position input, you can configure it in the trim and flap setup as described in the Garmin manual. 
3. You can configure the Amps gauge to display amps from the VP-X instead of from an external shunt.

GDL-51R

 

1. On the GDU 4XX  in configuration mode
1. Under the RS-232 interface setup page set serial port connected to the GDL-51R to "CONNEXT 57600 BAUD" A green check is show next to the connection when communication is established with the GDL51.

GTX-45R

             

1. GSU 25 WITH GTX 45R 
1. NO CONFIGURATION REQUIRED FOR GSU 25 SERIAL PORT 
2. GDU 4XX RECEIVING TRAFFIC/WEATHER FROM GTX 45R 
1. THE GTX MAY BE CONNECTED TO ANY SERIAL (RS-232) PORT ON THE GDU 4XX FROM 1 TO 5. ONE CONNECTION ONLY PER GDU.
2. ON THE GDU 4XX RS-232 CONFIGURATION PAGE 
1. SET SERIAL PORT CONNECTED TO GTX TO "CONNEXT 57600 BAUD" 
3. GTX X45R REMOTE MOUNT TRANSPONDER
1. ON GDU 4XX TRANSPONDER CONFIGURATION PAGE SELECT INSTALLED TRANSPONDER TYPE (E.G. GTX 45R) 
2. CONFIGURE HSDB DEVICES (GTN/GTS ENABLE/DISABLE) 
3. CONFIGURE TRANSPONDER SERIAL PORTS 2,3,4 FOR "CONNEXT FMT 1"
4. CONFIGURE ALL ADS-B OUT DATA FIELDS 
4. GTX X45R REMOTE MOUNT TRANSPONDER INSTALLED WITH GTN IN SYSTEM
1. ON THE GTN INTERFACED EQUIPMENT PAGE
1. SET ADS-B IN SOURCE TO "GTX #1"
2. ON THE PFD1 TRANSPONDER CONFIGURATION PAGE
1. ENABLE "GTN" ON HSDB DEVICES FIELD
5. GTN/GNS POSITION SOURCE
1. WHEN GTN IS CONNECTED TO A GTX 345R/45R USING ETHERNET, SELECT "GTN PRESENT" ON GDU 37X/4XX TRANSPONDER CONFIGURATION PAGE
2. ON THE GTN/GNS RS-232 CONFIGURATION PAGE SET SERIAL PORT OUTPUT CONNECTED TO GTX TO "ADS-B+" OR "ADS-B+ FORMAT 1" 
6. GTX X35R/X45R REMOTE MOUNT TRANSPONDER
1. ON GDU 4XX TRANSPONDER CONFIGURATION PAGE
1. SELECT INSTALLED TRANSPONDER TYPE (E.G. GTX 345R)
2. CONFIGURE SERIAL PORT CONNECTED TO ADS-B POSITION SOURCE TO "ADS-B+"
3. CONFIGURE HSDB DEVICES (GTN/GTS ENABLE/DISABLE)

GTN-650 to PFD

1. GTN 6XX/7XX
1. ON THE ARINC 429 CONFIG PAGE
1. SET IN 1 SPEED TO "LOW"
2. SET IN 1 DATA TO "EFIS FORMAT 2"
3. SET OUT 1 SPEED TO "LOW"
4. SET OUT 1 DATA TO "GARMIN 429" (GTN V6.50 AND LATER)
5. SET OUT 1 DATA TO "GAMA FORMAT 1" WHEN "GARMIN 429" NOT AVAILABLE
6. SET SDI TO "LNAV 1"
2. ON THE RS-232 CONFIG PAGE
1. SET CHNL 3 INPUT TO "MAPMX FORMAT 2" WHEN THIS FORMAT IS AVAILABLE
2. SET CHNL 3 OUTPUT TO "MAPMX" WHEN "MAPMX FORMAT 2" INPUT NOT AVAILABLE
3. SET CHNL 4 INPUT/OUTPUT TO "CONNEXT FORMAT 2" WHEN CONNEXT IS USED
3. ON THE MAIN MAIN INDICATOR (ANALOG) CONFIG PAGE
1. SET SELECTED COURSE FOR VLOC TO "IGNORED"
4. ON THE VOR/LOC/GS ARINC 429 CONFIG PAGE
1. SET NAV RADIO TO "ENABLED"
2. SET TX SPEED TO "LOW"
3. SET SDI TO "VOR/ILS 1"
2. G3X
1. ON THE GDU 4XX/37X RS-232 AND ARINC 429 CONFIG MODE PAGES
1. SET THE CONNECTED GDU 4XX/37X RS-232 CHANNEL TO "MAPMX"
2. SET ARINC 429 TX 1 FORMAT TO "EFIS/AIRDATA FORMAT 1" AND "NAV 1"
3. SET ARINC 429 RX 1 FORMAT TO "GARMIN GPS" AND "NAV 1"
4. SET ARINC 429 RX 2 FORMAT TO "GARMIN VOR/ILS" AND "NAV 1"
2. ON THE GDU 4XX RS-232 CONFIG MODE PAGE WHEN CONNEXT IS USED
1. SET THE CONNECTED GDU 4XX (PFD) RS-232 CHANNEL TO "GTN CONNEXT 2"

Starting to look like a plan(e)

Dad came out for a couple of weeks to help me button up the bottom wing skins and install the wings onto the plane. It took about three total days to rivet the wing bottoms. Towards the end, we were just getting the hang of it and the right communication signals for what a "1/2" vs "1/4" hit is ;)

I still need to seal the rivet the left rear tank baffle, but today was a milestone. After a good pressure test I was able to install the right tank.
The prop is on. 

Cowl Photos

TODO: Come back and add words to this.

Cross bar dimensions

I keep forgetting to make a post about my engine mount crossbar dimensions, so while this is old news I still want to document it. With my cold air induction (Thunderbolt) I had to lower my crossbar in order to gain enough clearance for the engine.  The short of it is that the rear of the sump on the cold air setup is about ~3/4 lower than the standard sump.

This is a pretty standard modification and Barrett sells these crossbars with their cold air induction. The dimensions of my setup are in the photo below.

I unfortunately measured once and cut/welded twice. The first time I welded one in, I more or less eyeballed in the dimensions while the engine mount was on the weld table and not on the airframe. After I mounted the engine and allowed the mounts to sag a bit, I was not happy with the clearance I had remaining (1/16"). As such, I removed the engine off of the mount and welded a new cross bar in place. The tubing was pretty easy to find and I just ordered it from: McMaster Link

With the Thunderbolt IO-540 setup with Cold Air, .82" of cross bar drop got me a little over 1/2" of clearance on a mostly settled engine.

AUX circuits complete

The wiring is coming along nicely, today I was able to clean up the existing and complete the rest of the AUX power circuits.  With my GMA-245 on AUX power, I spent a little more time than I care to admit with my headset on, streaming pandora over bluetooth from my phone into the entertainment system, making radio calls to myself.

I am going to move the wiring on the AUX fuse block around a little bit to make it easier to replace fuses. In my head when I was creating the schematic I thought it would be best to spread the fuses out to make them easier to identify. I found that when I was finding and pulling the fuses in the cabin that it is actually easier to identify the correct circuit if the fuse block is fully populated.

Fuse Links

I made the decision to bring my AUX shunt inside the cabin co-located with my AUX fuse panel. As a reminder, I decided to shunt my AUX current draw. My main AMPerage draw will be read from my main bus via the VPX Pro.

The install manual directs you to put a fuse link on the shunt to GEA24 connection. I decided to burn up 6 inches of 26AWG and was surprised by the amount of smoke (and smell). Rather than create a fuse link out of lighter gauge wire, I decided to put in an inline fuse.

I ordered some 1A axial fuses from Digi-Key. The part number was F2313-ND:

 I soldered this onto some 22AWG wire in a crossing pattern to bulk up and protect the leads on the fuse. Then used some clear heat shrink to protect everything.

I made a couple of these and connected them direct to the + and - of a 11v battery. They blow pretty quickly and do not even give off any noticeable heat in the process. I am going to give this a go and hopefully they do not randomly blow all of the time.

AUX Bus Fuse Tray

My AUX buss runs of a secondary ETX-900VNT battery. This buss supplies the backup power to the avionics which have AIRCRAFT PWR 2, and is controlled via a rear mounted contactor specifically for the AUX battery. The AUX battery gets charged via a X-FEED contactor.

I ended up with a second battery because something like the TCW IBBS did not provide me enough power to run things like my Engine Ignition with enough safety margin. So then I was looking at two IBBS, and at that point it was worth just putting in a secondary large battery and buss. When I originally designed this buss I had in my head that the buss would not draw over 30A because I was intending to not put a X-FEED contactor in, rather get power to the buss via a  Schottky Diode.  I still like that idea alot, but the main problem that I had with that approach was that I am really trying to use parts that I could get at any random airport with a maintenance shop.  I don't want to be lugging around my own spare parts everywhere I go.

My MAIN bus has a Vertical Power Electric Circuit Breaker, on the AUX bus I decided to go with fuses. Again, this is my backup system, by the time this thing is blowing fuses, I have some serious issues beyond thinking about reseting breakers. With the 30A max notional draw, I ran a 8GA from the rear mounted contactor up to a fuse block that I installed on my mid-panel. I looked at this fuse block for at least 3 months and every scenario I ran through in my head every time I saw it, this was a horrible idea (although it is a nice spot for it being out of the way). 

There were a lot of things I did not like about the fuse block from above. First, it is not accessible without removing the right panel. That alone makes this a bad idea. Second, I ended up mounting my GTX45R on a rack that I built coming up on top of the ignition brackets shown above. This obscured the fuse block even further. Also, the orientation in which the wires leave the fuse block put half of them rubbing against the GTX tray.

So I moved things around.

I removed the fuse block from the mid-panel and replaced it with my Manifold Pressure Sensors for my FlyEFII System 32. I wanted to keep these on the inside because, well, just because. I then milled out a 6160 1/8" bracket to connect the panel to the mid-panel which will hold the new fuse block.

This took me some time to figure out how to best mount everything, and I am really happy with it. I wanted to keep everything removable, I am not sure why, but it seems like a good idea. The tray itself is held to the mid and rear panels by #8 screws coming up from the bottom. The main wire is coming up through the tray itself inside of a locking grommet. The locking grommet is much bigger than it needs to be because you can fit the terminal (1/4") through the grommet itself.

The angles are hard to see in the photo, but I shielded the power cable with nylon braid, then built a small bracket out of 1x1 angle to bolt in an adel clamp that keeps the AUX power cable centered in the hole. This also isolates the cable from moving and putting stress on the terminal itself. The 8GA 1/4" hole un-insulated terminals have a pretty weak feeling to them...

You will notice that the AUX power does not go to the new sealed bottoe facing fuse block itself. It goes to the 1 and only standalone shunt I have in the plane. This will allow me to read my MAIN current draw from the VPX and the AUX current draw from this Shunt going through the GEA24 Shunt 2.

I am pretty happy with this setup. While it is no where near complete, I like how it is coming together. The fuse block has a sealed lid on it. That lid is facing downwards and you can actually remove the cover and touch the fuses from the co-pilot seat while in a normal seated position. You would have to use a mirror or something to make it easier to replace a fuse in flight, but it would definitely be possible.

Also, I am pretty proud of myself that I remembered my ELT and HOBBS meter are at the bottom right of my right panel. Before I drilled I discovered that the HOBBS meter was dead smack in the way of where I was going to put everything.