Category: Wiring

Fuel Tank Drama Continues…

October 22, 2021 – I have given up on my right tank fuel quantity issue, for now…

I got a new sensor from Van’s. I installed it, reinstalled the tank, ands started the fuel calibration again. Believe it or not, no help. The sensor and float move just fine, and electrically it works. but when it’s in the tank, there is still no apparent movement (i.e. voltage change) when I add fuel.

I tried bypassing my wiring; running a wire from pin 21 of the Dynon EMS to the sensor. That was no help. I also double-checked the ground.

OK. I’ve had enough. I decided to go scorched-earth, and reconfigure the tank back to the fixed pickup tube and relocate the float sensor to it’s normal place in the inboard bay of the tank.

I removed the tank again, and ordered the pickup tube with a screen and the anti-rotation brackets from Van’s.

I removed the access plate on the inboard rib, to see if I could tell if the float was hanging up. I was able to stick something through and move the float. I also checked the resistance while I was moving it. I couldn’t find anything wrong.

I cut an access hole in the back baffle of the tank as needed to get access to the bay.

Here’s the flop tube inside the tank.

I removed the flop tube and the float from the next bay over. I left the small mods that are installed with the flop tube; there’s a twisted strap that keeps the flop tube from hanging up in the next rib, and there’s a small trap door that acts as a check valve to keep fuel in the inboard bay so fuel doesn’t slosh outboard and starve the flop tube.

I drilled the hole in the inboard access plate for the sensor…

…and when I got the pickup tube, I located that hole, then secured the tube in place along with the anti-rotation bracket.

So here’s everything in place:

The float does not and cannot hang on anything. It also doesn’t touch either the top or the bottom.

I made the panels to close the tank back up and installed them.

Two days later, I pumped up the tank with a bike pump and used soapy water to look for leaks. Absolutely nothing…

I plugged the hole at the leading edge where the flop tube was mounted, and where fuel exited the tank. I used an AN fitting with two AN caps and thoroughly sealed them inside and out…

I also had to make a new fuel line to the fuselage since the location was different…

I installed the tank, and proceeded to begin the calibration.

Guess what?… It still doesn’t work.

Well, I was able to get a “calibration”, but I had to thump the top of the tank with my fist to get the sensor voltage to change after each 2-gallon addition.

I filled it to 21 gallons, and the Dynon accepted the calibration.

I proceeded to drain 10 gallons from the tank to put in the left tank. The indicated quantity did not change.

My drain valve was dripping, so I drained the rest of the fuel so I could check the o-ring on the drain. I did expect to find a piece of aluminum stuck there, and I did. I reinstalled the drain. With an empty tank, Dynon still indicated 20+.

OK. This airplane needs to be flown, so I decided I’ll not hit my head against the wall any more, and just manage the fuel for the time being.

I may call Van’s at some point, and probably will end up ordering another sensor, but maybe not until the condition inspection next year.

Time: 24:30

Connecting Wing Wiring

April 27, 2021 – Now that the wings are on I can connect the wing wiring.

I safetied the tank attach bolts. Not sure why they need to be safetied, since they go into a nutplate that locks, but OK… I drilled the safety wire hole in the steel bracket.

I also installed the fuel lines.

I ran the pitot and AOA tubes into the fuselage and back to the ADAHRS, then connected the heat controller. Put power on the airplane and the heat works. I don’t have a message saying the heta is either on or off yet; I’ll set that up later in Dynon.

I ran and terminated the wires for the roll autopilot servo. The Skyview network portion is connected to the hub in the back.

I plan on connecting the wires for the lighting and the stick grips on a terminal bar under the left seat.

When I tried my lights, I had crossed the wires for the right landing light and the right nav lights. Got that figured out and now the lighting works correctly.

Time: 25:00

Wing Prep and Reinstall

April 2, 2021 – The wings are installed, hopefully for good!

With the wings off, I prepped the holes for the fairing that wraps around the wing root.

I also added holes for the fuel quantity wiring where it will enter the fuselage. These wires are forward of the wing spar and there was no other entry point except where the fuel feed lines go in. I got very small ID grommets from Spruce for these holes.

I decided it was time, so I gathered my faithful friends and helpers.

After it was all done, we took a breather, and there was the usual hangar talk.

The next day I finished the wing install.

I torqued the mount bolts:

…and I installed the aft spar bolts and the fuel tank attach bolts:

No pictures, but I then routed the wing wires from the wings into the fuselage. That wasn’t a lot of fun because of the limited space between the wing roots and the fuselage skin.

Time: 15:45

No Smoke!!!

February 3, 2021 – Well, I fired up (poor choice of words) the panel using my power supply. No pops, sizzles, smoke or fire.

It also was pretty underwhelming, because only the left screen turned on. I tried the dimmer for a lit rocker switch, and it worked. The glareshield fans also worked. So I call it a win. I know there are several things to do to get everything up and running.

I needed to get into the VPX and get it set up. The interface external to the VPX is ethernet. Well, my laptop has no ethernet port, so I used an alternate method suggested by Vertical Power. I used a wireless router.

Once that was complete, I looked over at the panel and saw this:

The right screen came up!

I downloaded the latest software from Dynon (as of January 27) and installed it on both screens.

I then went in to system setup and set up the serial ports and scanned for devices on the Skyview Network.

The issue I then had was that the screens weren’t talking to each other. You can “daisy-chain” the devices on the network, which I had. But it seemed evident that maybe I needed to directly connect the screens to each other. So I ordered a 3-foot Skyview Network cable. When I got it, I rearranged the cables between devices. It worked!

I decided to prepare the wings for installation, so I could get ALL the wiring connected and do all the panel setup maybe at one time.

Pitot Tube and Heater

I started on the pitot tube. I was given a brand-new Dynon heated tube. I had seen online where people mounted the heat controller to the wing access panel.

I took the tube out and realized I didn’t have any of the AN hardware I needed to connect the tube to the pitot and AOA lines. I visited a local avionics shop and got most of what I needed from there. In the meantime, I drilled the holes to attach the tube into the mast. I already had holes in the mast from a long time ago, so I transferred these hole locations to the new tube. Drilled with a #36 bit and tapped for a #6 screw.

I made a bracket to support the plastic pitot and AOA lines and keep them away from the aileron bellcrank.

I’m on hold for the parts I’m still missing, so I moved on to the autopilot roll servo in the right wing.

Autopilot Roll Servo

Here’s the right wing aileron bellcrank without the servo:

The servo bracket replaces the small mounting angle there in the center of the picture. You have to take the bellcrank partly apart, because it has to be drilled. This is where the servo control rod attaches.

I installed the new bracket, and then bolted the servo in place.

The control rod is supposed to be 5 inches long.

Here’s everything installed.

Now it’s time for wiring. I installed the DB9 connectors on the servo and the harness, then ran the harness through to the wing root. I had to do this twice because I had to avoid contact with the aileron bellcrank travel.

For right now, I secured the connection using the threaded bolt holes in the servo itself. This will place the connection on the aft side of the servo when it is on the airplane. The harness runs between the arms of the bellcrank and out through the wing ribs.

Time: 11:45

Right wingtip complete

October 23, 2013 – With the right wing on the table, I wanted to arrange the wiring so that the wingtip would be removable and the wiring would be reasonably secured.

I cut the 4-strand cable for the strobe to length and terminated the wires for the wingtip. I clamped the wires to the rib I installed in the tip. Here’s a before and after:

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Here’s close-ups of the wiring inside the tip, and of the terminal connection on the wing itself.

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I temporarily installed the wingtip to the wing, mainly just for storage. The phillips head 4-40 screws I have will not work later on. I’ve already stripped a few of them, so I’ll be getting torx fasteners later on.

Of course I had to try my lights with everything installed.


I’m calling the right wingtip complete.

A friend from work came over and helped me put the right wing back in the stand and the left wing on the table.

Time: 2:30

Continuing wing tip lighting assembly

October 10, 2013 – It feels like forever since I’ve done anything on the airplane. Money issues and just life in general have gotten in the way, but things may be looking up.

I continued with the right wingtip lens. They’re trimmed about as well as I can get them, and then I transferred the holes for the attach screws. LJ helped clean up the cut edges and the screw countersinks.

Wingtip lens attach screw location 101013003

I also had to repair the foam rib I installed in the right wingtip. Part of it had pulled away from the tip.

101013004Before I installed the lenses, I needed to finalize the installation of the lights. I had made some spacers for the mirrored plexi, but I didn’t like them because they were hand cut and not very straight. A good friend of mine at work helped me out by cutting spacers on his lathe at home. They came out beautifully; all the same size and nice and smooth.

I assembled the lights and installed the lens.

101013005 101013006

The next thing I’m working on is securing the wiring in the wingtip so that when the wingtip is installed, the wiring will be safe.

I put the right wing on the table so it will be in an as-installed position. I realize that some people will say that this is over-engineered, but coming from a maintenance background, I want it…well…maintainable.


Time: 5:00

Wingtip lighting almost done

March 5, 2013 – I’ve come a long way since my last update.

Since I did the green LEDs last time, I got the red ones done:


Here’s a guide to how I wired the LEDs:


I installed the strobes on the wingtip cutout backing plates I made. As I wrote before, I didn’t want to attach the strobes to the wingtip fiberglass.

030513007 030513006

These are the outside and inside views of the strobes. The strobes are Whelen Vertex Hide-a-way Super LED strobes that I got from Strobes N’ More. If they turn out to be not what I need, the cutouts are the standard 1″ hole, so I can drop in a regular strobe if required.

030513005The next thing I needed to do was to make spacers for the screws for the mirrored plexiglass since it sits on top of the LEDs. I needed 1/4″ OD and ID to fit a #6 screw. I found longer spacers and cut them to fit. Unfortunately, the height I need is only 1/8″, so these were kind of a pain to make. They aren’t pristine parts, so I’ll be replacing them with better spacers at some point. For now, they do the job.

Here you see the spacer between the rivets for a nutplate:


…and placed over a screw for the plexiglass:


Here are side views of the plexiglass installed with the spacers:

030513004 030513003

I hooked up both wingtips to power, and…


…everything works!

Not the best quality, but you get the idea…


I started installing the wiring on the outboard wing ribs. I made brackets for the LED drivers. I used thermal epoxy to attach the driver pucks to the brackets, then screwed the brackets to the ribs. I plan on using the terminal bars to connect the lighting to the wiring, so I installed terminals on the driver puck wires.

Time: 6:40

Continued wingtip lighting

February 11, 2013 – I continued work on the wingtip lighting by drilling screw holes for the plexi for the strobes, then drilled the strobe holes.

I drilled the holes in the plexi to 1″ to fit the strobe itself.


I took the corresponding holes in the fiberglass underneath to 1 1/2″ to fit the body of the strobe. This will allow the strobe to sit higher in the opening. I will attach the strobe to the plexi and the aluminum underneath, instead of also going through the fiberglass.

I then cut out the face of the wingtip cutout where the nav lights will be. This will allow for a bit of cooling. Some people have installed heatsinks onside the wingtip. I’m going to wait to see how hot the LED assembly will get before I go through that work. It will save a little bit of weight.

Below is the sequence for these cutouts:

021113002 021113003

021113004 021113005

I drilled the nutplate holes, countersunk them, and installed the required nutplates.

021113006 021113007 021113008

Then I started in on the soldering. I have to do some research, but I had a heck of a time soldering to the contact points on the LEDs, plus I know now some have to be redone because the wires run where the plexi will sit down on top of the LED assemblies.

Here’s my initial wire arrangement:


Hooked up the driver and power…and…WooHoo! It worked.


This puppy is BRIGHT!!! Some of the trial and error work is done, no smoke leaked out, so I can clean up the wiring a little bit, learn from my mistakes, and move on.

Time: 5:30

Started wingtip lighting

February 4, 2013 – I’ve been looking forward to this; I started work on the scratch-built LED nav lights.

I have seen this lighting on several other builders’ websites, and I really liked the clean updated look. It will also be cheaper than standard lighting, and I’m not too concerned that they won’t be bright enough.


I had previously made templates of the cutout in the wingtips to form the backing plate, so  I cut out .020″ aluminum to fit. After it was shaped, I drilled for the attach screws in each corner. The clecos in the center were to hold the metal in place so I could shape the edges.

I used the bandsaw at work to cut the plexiglass. I am going with mirrored plexiglass for now.

I made a template for the LED holes, and transferred the holes to the plexi with a #40 drill. I measured the LED lens housing at .270″, so I had some room to make up. I slowly stepped up the holes through a range of drill sizes. As the holes got bigger, I used core drills where I could. These make cleaner holes and can go through plexi with no damage. 

020413002 020413004

020413005 020413006

The last picture above shows the core drill I used for the final hole size, which was .278″.

I gently deburred the holes, and used a 5/16″ countersink to countersink the holes to act as reflectors for the LEDs. This went a lot easier than I thought it would.

020413007 020413008

I also needed to drill screw holes in the plexi to mount them to the backing plates. I piloted them with a #40, then took them up to a #27 to accommodate the screws.


I had to order screws and nutplates from Spruce. I am using 6-32 stainless screws to mount all of this.

Now it was time to install the LEDs.

020413011I am using the Cree Rhea LEDs from LED Supply. I have 6 red and 6 green. I used Arctic Silver thermal adhesive to mount the LEDs to the backing plate. I marked the location of the LEDs on the plate, cleaned it well, then mixed the adhesive. I applied the adhesive quickly (this stuff has a short working time) to each LED and placed them in position. When all 6 were roughly in place, I set the plexi over them to position them correctly, then let it set up.


You can see the LEDs in place in the above picture.


Next, it’s time to wire the LEDs.

Time: 4:25

Right wingtip wiring

December 5, 2012 – I realized that I had only done the wiring for the left wingtip, so I sat down and terminated, heat-shrunk, and wire-tied as needed on the right wing. Still a little slow with the wire-tying, but I got it right eventually. It’s kinda refreshing to do something not with an air tool…

Time: 1:15

Worked on left wingtip wiring

January 24, 2012 – I think I’ve figured out how I want to configure the wiring for the wingtips. I want to have a disconnect so I can remove the wingtips if needed. I looked at plastic disconnects, like in the car, but I couldn’t find any that could be mounted to the rib, so I went with a terminal strip. Then I had to route the wires from the conduit to the strip so there wouldn’t be any stress on the wires.

I think I like how this turned out.

I also have had to learn wire tying. I’ve attempted it in the past, and I felt like I was relearning to tie my shoes. In fact, I was in a wiring class a few years ago at work, and the last thing we did before the class ended was wire tying. I was the last one to successfully do it. Nothing like an ego-booster…

I really should learn it with a piece of rope first…but I’ll be getting lots of practice anyway.

Tomorrow’s Wednesday, so that means it’s riveting day, and we should finish the bottom skins on the left wing…

Time: 1:00

Started work on wingtip lighting

January 11, 2012 – I had some time to tinker, so I took down a wingtip from its storage, and I made the template for the LED lighting for the position lights. I’m using the system done by David LaSala. Just barely got started with this, because due to the lack of funds for the fuselage, I want to do this work after the wings are closed.

Here’s the template I traced from the outline of the cutout for the tip.

Time: :20

Added wing wiring clamp brackets

December 31, 2011 – In addition to the clamp in the aileron bellcrank bay of the left wing, I also wanted to add a clamp on each end of the conduits in both wings to keep the edge of the conduit from wearing on the wiring. I made these brackets the same way I did the one in the aileron bellcrank bay. The standoff is 1″ from the bracket to the clamp.

I’m ready to start installing the bottom skins. I’ll start this after the first of the year when I can round up some help.

Time: 2:20

Wing wiring pulled

December 21, 2011 – I got all the wiring pulled through both wings that I know right now I’ll have in there. I had to wait on bulk 4-conductor cable for the strobes, and  I got that yesterday. I’m also leaving a string in there for future pull-throughs.

On another note, I also got a bench 14-amp 12V power supply a few days ago. Tested it on the strobes: worked great. Tested the landing lights (Duckworks rectangular 55W halogen): no joy. I eventually took a bulb out and tested it directly. No good. The bulb worked off my car battery, so I’m pretty sure it must be the power supply. I’ll post updates as this develops.

Time: :40

Installed wing conduit

November 27, 2011 – I started pulling the conduit through the wing ribs. I’m using the Van’s conduit which is basically the corrugated black plastic you can buy to contain computer and stereo wires, but this stuff  isn’t split. This stuff is a pain in the butt to pull through. The holes in the ribs are 3/4″, and the corrugation large diameter is .810″, so it’s a tight fit pulling this through, and it’s noisy. I sure like how it looks, though, and it’s very light.

I have read about how people have cut holes in it to accommodate wires exiting and entering at different points in the run. I decided that I really didn’t like that idea, since I’d have to worry about chafing, so I interrupted the conduit in the left wing bay with the aileron bellcrank. The stall warning wire enters at that point. I also will probably install an autopilot servo there in the future. Here’s the ends of the conduit in that bay:

And here’s a general picture of the conduit installed in the wing:

Here’s the end of the conduit at the outboard rib:

Once the conduit was installed, I pulled the wiring through. All I have at the moment is the landing light wiring and the stall warning at the mid-point of the left wing. I used the cotton ball trick that I’ve read about. WOW! That works great!

I tied a cotton ball to a string and placed it at the inboard end of the conduit.

I used a blowgun to blow the cotton through the conduit.

I tied the string to the wire and pulled it through.

Time: 1:15

Landing light wiring

June 12, 2011 – I installed the ground and power wiring for he landing lights. I decided that I wanted to use near-Boeing spec ground studs, and for the sake of maintenance I want to use local grounds whenever possible. I used snakeskin to protect the bundle coming out at the outboard side of the outboard rib, and clamped it in place. The ground stud there will be the ground for the landing light and the nav lights when they are installed in the tips.

Time: :55

Preparing landing light wiring

June 4, 2011 – I also replaced the ground wires for the landing lights. The wires that came with them are too short for where I want to place my grounds.

I started by cleaning the area for the ground with a bonding brush, then alodining the surface. This point on each outboard rib will be the ground for the wingtip lighting.

Here is the existing wiring for the landing lights:

Here is the new ground wire that will exit through the outboard rib and attach at the ground studs that will be installed:

Time: :45