Archive for the ‘Wiring’ Category

Wired Backup GPS – 6 hrs

December 15, 2013 1 comment

Sunday Dec 15, 2013

Today I finished wiring the dimmer and annunciator controllers. You can see the green dimmer controller through the opening in the panel for the copilot’s EFIS. I also wired up the Garmin 18X GPS which sends data to the Gemini PFD and the ELT.


Categories: Avionics, Wiring

Wired Up Annunciator Lights – 5 hrs

December 8, 2013 2 comments

Sunday Dec 8, 2013

On Friday night I started wiring up the annunciator light panel. I happened to have red, yellow, green, and blue wire so I matched the colors to the lights I was wiring. Looks pretty. I wired the lights up first with long pigtails to be trimmed after the lights are mounted in the panel.


This photo shows the lights installed and the routing of the wires to the annunicator controllers which are mounted on the subpanel.


The key benefit of the annunicator controllers is the ability to test all lights with a simple push button switch. Mine is mounted right next to the lights. This photo shows all eight lights glowing as I press the test button. Further testing revealed that the landing light switch glows all the time – even when the switch is off. That is because I wired the annunciator controller to the VP-X side of the light switch and the VP-X apparently puts about 5V on the switch wires to measure continuity to ground. That confuses the annunicator controller. I’ll have to figure out how to fix that problem.


Categories: Avionics, Wiring

Powered Up Gemini PFD – 1.5 hrs

December 5, 2013 1 comment

Thursday Dec 5, 2013

Tonight I wired power to the Gemini PFD which is my independent backup flight display. It only took two pins for the power, one for dimmer control, and one for RS-232 input in a 9-pin D-sub connector. It powers up with the Avionics Master switch as recommended in the Trutrak installation manual. It is nice a bright – in fact it looks washed out in this picture because the camera can’t capture the full dynamic range making the colors look more muted than they really are. Ignore the big X on the Skyview screen because I had the ADAHRS disconnected when I took this photo.


I had some difficulty with the dimmer control because I wired my dimmer pot up backwards, meaning that the brightness goes does as I turn the pot counterclockwise. That is opposite the intuitive approach which is to get brighter going counterclockwise. I’ll have to rewire the pot.

Categories: Avionics, Wiring

More and More Wiring – 16 hrs

December 1, 2013 Leave a comment

Sunday Dec 1, 2103

With a dual Skyview system there are no less than 15 wires that need to be spliced together so both displays are connected in parallel to key components. This includes all the serial lines from the displays to the GPS, ADSB, VP-X, transponder, and radio, plus audio outputs from the displays to the audio panel/intercom. When I started thinking about using crimp splices for all of these it just seemed crude and inflexible for future upgrades. I considered using an avionics hub from but one with the capacity for 15 or more pins costs nearly $100 so I decided to make my own using D-sub connectors. It uses two 15-pin connectors (one for each Skyview display) and two 9-pin connectors that interface with the GPS, ADSB, VP-X, transponder, and radio. All it does is interconnect the signals from all these devices with the necessary splices. I used solder splices covered by heat shrink tubing. Here is a photo of the completed hub. The most expensive parts are the pins and sockets. all together it costs me about $30 to make.


Here is a shot of the hub mounted on the subpanel between the two Skyview displays. I installed a couple of nutplates on the hub after this photo was taken so the unit could be mounted with #6 screws from the aft side of the subpanel. Then I terminated the Skyview signals into mating D-sub connectors that plug right into the hub. This feels much cleaner to me than a mountain of crimp splices.


Over the holiday weekend I continued making electrical connections including wiring up the panel switches.  Here is a view of the switch wiring on the pilot’s side. I put a file folder under the wires just to help you see them better.


I also wired up the canopy latch switch which is wired to the annunciator panel.


So far, everything seems to be functioning properly. Once I got the avionics master switch wired up the aileron trim motor began to function properly from the pilots stick buttons. I also completed a calibration of the flap controller and set that up initially at least with three positions; 10, 20, and 35 degrees. That was just a guess but after I did the flap position indicator began to function appropriately on the Skyview engine page. You can see it in the lower right corner of the display next to the aileron trim display which also works. Very cool.


I needed a second GPS as an independent source for the ELT and the trutrak Gemini so I bought a Garmin 18X which runs on 12V power through a lighter adapter. I needed a place to mount that adapter so I borrowed an idea from Jason Beaver and mounted it on the right hand side behind the panel. I made a simple plate for the adapter and you can see where I plan to mount it in this view. I primed it but I plan to paint it to match the interior before riveting it down.


Categories: Avionics, Wiring

More and More Wiring – 10 hrs

November 24, 2013 Leave a comment

Sunday Nov 24, 2013

Wiring continued this weekend. Progress is slow but steady. I estimate I have completed about 70% of the wiring job so far. One thing I did was assemble the 1K ohm resistor fuse for the starter annunciator lead. The resistor comes with the VP-X Pro harness kit. The resistor is soldered inline with the AWG 18 wire to the VP-X box and located physically close to the starter contactor.


This view shows the white wire routed along the red VP-X power wire to the starter contactor.


Here is a view from above looking down into the fuselage showing some of the point to  point wiring. I use a lot of zip ties to temporarily pull bundles together. It will get cleaned up more when I finish routing wires and finally lace all the bundles up tighter.


Categories: Avionics, Wiring

First Power-Up Successful – 9 hrs

November 17, 2013 Leave a comment

Sunday Nov. 17, 2013

I crossed another major milestone this weekend with the initial power-up of the VP-X and Skyview. I spent a good amount of time Saturday wiring up subsystems and there is still much to do but I got the VP-X wired to ground and power through the battery contactor. I want to try to test incrementally as the electrical subsystems are connected rather than wait until all the wiring was complete and hope for the best. So I flipped the Master switch, heard the contactor close and waited for the lights on the VP-X to flash, which they did. That’s good.

Before applying power to any avionics including the Skyview I needed to configure the VP-X. That means telling it what is connected to each pin and what current limits to set for each pin. That is done through a software program provided by Vertical Power. I downloaded it onto my netbook and connected it to the VP-X by an ethernet cable. Sure enough the green light on the VP-X flashed indicating it was talking to the laptop. The software detected that the firmware was out of date on the VP-X so it updated it before I could load the configuration file I had created on the Vertical Power web site.  After it rebooted the VP-X I was able to complete the configuration successfully.

This photo shows the laptop connected and the firmware being updated.


Then I connected the power wires for the Skyview primary flight display (PFD) to the VP-X. The VP-X is set to power up the PFD immediately when the Master switch is closed so I flipped the switch and held my breath. No smoke seen and the Skyview began to boot up. Hooray!


Initially it showed a black screen with big red X’s indicating that it could not talk to a GPS, ADAHRS, or EMS. The lack of GPS and EMS made sense because they are not wired to the Skyview yet, but the ADAHRS is connected. Immediately I remembered that I had connected the ADAHRS through the Skyview network port on the secondary Skyview display which is not powered yet and I thought that might be the problem. But after thinking it through I concluded that should not matter because the network ports are passive connections and the primary display should see the ADAHRS through the secondary display. After all if one display fails in flight you don’t want it taking out the network attached through that display.

So I continued to research the problem in the manuals until I read that the display won’t see the ADAHRS until a network setup is completed. But then I not could figure out how to run a setup because there is no Setup option on the Skyview menu. Further reading led me to the secret. Press buttons 7 and 8 together on the PFD and it will enter setup mode. Eureka! I was able to run a network detection and identify the ADAHRS. The firmware was out of date so it did the update for me and then connected to the ADAHRS.

This view shows the attitude, Map, and EMS displays. The GPS is still not connected so that is off-line but there is real data in the other two sections. This was a good day!


This was exciting but I also had the opportunity to help Bruce Hill, a fellow builder from Ramona, CA to make labels for his instrument panel on Saturday afternoon. He read that I had some success with Decal Pro and contacted me about getting some help. He came over with his panel and a graphics file and we spent about four hours making and applying most of his labels. He took a few home for installation later. He was happy with how it turned out and I was happy to help him.

Categories: Avionics, Wiring

Oil Pressure, Fuel Pressure and P-Mag Wiring – 4 hrs

November 10, 2013 Leave a comment

Sunday Nov 10, 2013

Continuing with the wiring fun I wired up the fuel pressure and oil pressure sensors to the Skyview EMS module. The sensors are the two brass devices with the three-color twisted wires routed through the pass-through.


On the inside of the fuselage the wires are spliced to the associated wires in the EMS harness including the +5V wires that I spliced together last week. I spliced the sensor wires with enough extra slack that I could cut and replice again if necessary.


I also started wiring up the P-Mags. I first installed a jumper between pins 2 and 3 to force the P-Mag to the A curve for controlling advance. This is because the engine is new and not broken in. The B curve will produce higher CHTs so the A curve is recommended, at least through the break-in phase. I routed the other wires out through adel clamps to the forward fuselage.


Categories: Avionics, Wiring

More Wiring – 8 hrs

November 9, 2013 Leave a comment

Saturday Nov 9, 2013

I admit I am slow at this. It takes me hours to arrange and make these electrical connections because I don’t want to create a rats nest of wires. All the details have to be determined as I go – such as the routing of the wires, tie down locations, and most importantly the wire length. Today I connected all the wires for the EGT and CHT sensors for cylinders 1 and 3. This photo is the fruit of about 4 hours of work.


I next made two 26 AWG fusible links from a kit I bought from B&C Specialty. These are for the ammeter shunt.


Here is a photo showing the wires for the ammeter shunt installed including the two fusible links. I also wired the master switch to the battery contactor. I confirmed that the contactor closes when the switch is thrown. That is the first test of the power circuits.


Categories: Firewall Forward, Wiring

More Electrical Wiring, Comm Antenna Doubler – 12 hrs

October 27, 2013 Leave a comment

Sunday Oct 27, 2013

Now that all the wires that run through the spar and the center tunnel to the tail have been loosely laid in I was able to tidy them up and install some tie bases to secure them. In this photo you can see the wires running along the tunnel next to the elevator pushrod. Next I terminated the wires for the flap actuator and flap position sensor into their respective connectors and mated them.


I trimmed the excess length off the power wire from the VP-X to the ADSB module and terminated that into the D-sub connector. The ADSB wiring is now complete on this end.


Likewise I trimmed the excess length off the power wire from the VP-X to the transponder module and terminated that into the D-sub connector. The transponder wiring is now complete on this end.


So the wiring in the bay aft of the baggage compartment is now done and I put the lower rear panel in place with clecos, installed the tunnel cover with screws, and put down the carpet in the baggage compartment.


One of the wires coming out of the engine monitor module is a +5Vdc supply which must be split to power the manifold pressure, oil pressure, and fuel pressure sensors. For this I installed an in-line crimp splice with one in and three out. It is mounted next to the EMS module, In this photo you can see it mounted to the rib.


On the other side of the fuselage I terminated the wires to the manifold pressure sensor (including one of the +5 Vdc wires mentioned above.


Last but not least my supportive wife helped me rivet the doubler plate to the fuselage for the comm antenna which is located under the pilot’s seat.


Categories: Avionics, Wiring

Mounting Radio – 8 hrs

October 12, 2013 Leave a comment

Saturday Oct 12, 2013

My final piece of avionics arrived this morning via FedEx truck – a Garmin GTR 200 comm radio. I’ve had this on order for almost a month. It’s the latest model and has been on backorder so I was glad to finally get it. Here is a view of the faceplate as it came out of the box.


Of course the radio included the tray so I immediately set about mounting the tray in the radio stack under the audio panel. I designed my panel cutout to allow 1/8 inch clearance between the GTR 200 and the audio panel for cooling so I had to align the GTR 200 tray to the bottom of the cutout in the panel, mark the hole locations then drill them through the side ribs of the stack. Here is a view after I mounted the tray to the side ribs. I also made .062 thick spacers that  go between the trays and the side ribs so I could install screws near the forward ends of the trays into the side ribs for better support. This box is pretty rigid now.


Here is a photo taken as I checked the fit of the stack in the panel. Everything lines up nicely.


Then I put the panel back into the fuselage and set it up to align two pieces of aluminum angle that will secure the tray to the subpanel. You can see one temporarily held in place by a shop clamp.


But before doing that I needed to change gears and reinstall the tail feathers on the aft fuselage so I could determine how to route the wires to the strobe light on the lower rudder fairing. To do this I needed to back the airplane up so the tail sticks out of the garage because the rudder is too high for the garage door. The weather was great today and I needed to get this done and get it disassembled before dark so I put my focus on this. Here you can see the vertical stabilizer and rudder in place. I got some funny looks from people driving by the house today.


After examining my options and doing several iterations with the rudder on and off I drilled a hole in the aft bulkhead about four inches above the lower hinge and I cut a slot in the rolled skin of the rudder for the wires to pass through where they turn downward past the hinge and exit into the region where the lower fairing mounts. I am optimistic this will work well – although I have not seen it done this way before. Well that’s the fun part of a homebuilt airplane. I installed a snap bushing where the wires pass through the bulkhead and I will install braided sleeving over the wire bundle which is actually a twisted shielded triple with an outer jacket so it is already somewhat scuff resistant. I pulled the wires through so they would reach the strobe light with about 6 inches of margin and marked it with a piece of tape at the aft bulkhead. Look between the rudder and the aft bulkhead to see the wires.


Here is a good view of the slot. I placed it above the second rivet in the rolled skin and cut it wide enough to allow the rudder to swing from stop to stop without hitting the wires. Here is one option to protect the edges wires from the raw edges with caterpillar edging from McMaster-Carr. I might glue these on with ProSeal. I plan to look at other options as well. With this done I ran the tail strobe wires from the seat pan area under the baggage compartment, through the aft fuselage to the tail using that tape mark to determine how much wire to leave hanging out until I get it terminated to the strobe.


Categories: Avionics, Wiring