Section 19 Wing Systems Routing

RV14 Build August

Wing Systems Routing

I thought going into this section that it would be relatively straight forward, but I found a way to make it harder lol. First by wanting a Regulated GAP26 that required me to add some wires it also required 2 air lines. All this extra made for the snap bushings in the ribs to be WAY too small.

First I ordered a bunch of stuff from Stein to install in the wing before I closed it out. 

Regulated GAP26

Magnetometer

GTP-59. My plan at this point was to install this in the wing walk area on the fuselage, but turns out Vans has a hole in the left wing for it already so I need to make room in the snap bushings for this as well.

Starting the wiring process

Even with the stock wire bundles it became clear that the smallest size snap bushing the instructions call for was inadequet so I borrowed an idea from other peoples blogs and got a .5" step bit to open them up. This worked okay but I found a Vans article saying you can open tooling holes up to 5/8" and drill others to 3/4", going a little bigger would have been useful.

After I installed the new snap bushings I bought from Heyco and pulled the extra wires I needed I realized that I wanted to terminate my new wires into the same Molex connector if possible, but that means I needed to change this to a 12 pin.

New Wiring layout.

Got the dremel out an cut the bracket to size.

Since I was at it, I didn't like the way the Molex connector for the Autopilot servo Roll trim mounted so I moved that too. It gives it more clearance from the skin for the wires to bend down and make the turn.

This is what the molex would have looked like and the space the wires had to make the turn.

This is after, a lot more room hopefully less trouble with potential chafing.

Trimming the bracket.

Next I needed to clean up the wires, they all were a few inches too long so I trimmed and repinned where necessary.

I added heat shrink labels to the wing tip end of the wires...IDK thought it might be helpful in the future.

The nav and landing lights share ground and you have to splice these together. 

I used a solder sleeve to add the nav light ground into the landing light ground wire.

Connecting the GAP26 wires to the wires I added. I did twist the power and ground, but I was told its not necessary. 

Next thing left to do that I didn't get a good picture of was wire protection. I used a split braided wire wrap to protect the wire between grommets where it ran next to the spar, bolt heads, and rivets.

I used a spiral wrap for the wires going to the stall warning and the power ground wires a ran for a future ER Fuel Tank pump.

Finally all the wires are in and terminated.

Not enough room in a single snap bushing for both pito/aoa lines to a ran them down 2 seperate.

Wing Systems Routing 22 Man Hours

Section 18 Fuel Tanks

RV14 Build July and August

Fuel Tanks

I decided I may want to install ER tanks in the future so I am putting "Fuel Bung" kits from Hotel Whiskey in the tanks now so that if I do get ER tanks in the future the infrastructure will be installed already.

I struggled more than I should have in drawing out the rivet holes on the bung kit, thanks to Matt for recommending the protractor.

We used a flexible hose connected to the shop vac, and my iphone endoscope to get it in the correct location while we drilled.
Close up of the set up

View from the endoscope.

Final drilled and marked to install in the correct location.

Next I went on to work on the fuel float sensor. Checking the sensor with the Ohms meter.

Then I bent of the float wire. I broke 1 so this picture below is me trying to fabricate one from a steel rod that I bought. The rod was too soft so I ended up buying a new sensor since I couldn't find the part.

Simply screw the float sensor in and check the float.

I used the endoscope again to see how the float sits in the tank. Lots of tweaking to get the float to the correct orientation.

Against the top skin "Full" position.

Against the bottom skin "Empty" position.

Backed out view of the empty posistion.

Now that the fuel senders are in time to pressure test. First tank I had trouble right away with this plug. I tried 3 different thread sealants and could not get it to test well. After looking at it closer it would appear that the leak is coming from between the skin on the tank and the flange not the threads.

I used my endoscope to see inside and it does look a little light on sealant on the one side.

This is the plug location in question, I can't find a place that it ever gets used so I have no idea why Vans put it in?

Left the other tank overnight and still holding strong.

Used soapy water to check for leaks.

Sending the bad tank back to vans to repair.

Its nice that Vans stands by these and will do the repair, kind of a bummer that it needs done in the first place.

Fuel Tanks 24.5 Man Hours

Garmin GAP 26 Regulated Heated Pito Tube

 RV14 Build July and August

GAP 26

The RV plans have a simple tube for pito, so installing the GAP 26 especially the regulated heater takes some thinking and planning.

After lots of messing and testing locations I decided that I wanted to install the Pito tube 2 bays outboard of the access panel to get it further away from the tie down. But I did mount the the heater controller in the same bay as the most outboard access panel. I measured the heater holes and drew them out on the rib, drilled pilot holes and then put the controller up and final drilled.

I then installed nutplates. This was tricky to drill and one of them wasn't lined up because of the rib lightening holes.

I think 3 nutplates is more than enough, but I did put in the the fourth that I cut 1 of the lugs off and installed 1 rivet.

I ordered the Gretz Pito Mast from Stein. The plans assume you are installing with the wing skins off still so I had to change it up a bit. 

I bent a simple L brackets from scrap sheet metal and put the mounting plate on then used my ruler to level everything to how the bottom skin fits.

After putting the skin on and seeing where the rivet holes would most likely go I made a larger L bracket and a shim to replace the backing plate so I had better control to drill through. The 2 horizontal pieces of aluminum as there to line the bracket and backing plate to the correct height on the rib with the lower skin when installed.

I then drilled 4 holed in the L bracket and Rib. I plan on using MSP 42 pop rivets here.

I made another shim the same thickness as the spar flange, so the backing plate would sit correctly on the skin for drilling. I first clamped the backing plate to the spar flange and match drilled the holes in the plate. Then match drilled the holes into the shim so both would cleko to the skin. The edge distance was a little off so i stepped in 1 line of rivets a little and used my rivet spacer to drill these.

Next was to cut the hole for the pito mast.

Used the dremel router bit to kit out the middle.

The mast hole in the backing plate is a little undersized so you can grind it to fit, so I had to shape the backing plate and skin to the pito mast, but it made for a nice tight fit.

Last was to match drill the holes into the skin into the L support bracket on the rib.

I got a little lucky that the stock wires on the GAP 26 controller are just long enough from the final mounting locations to just come out of the mast for installing and maintenance in the future.

How everything looks with a service loop once done.

I haven't read that people have problems with magnetic interference on the magnetometer, but just to hedge my bets I twisted the power and ground wire I had to run to the GAP 26 from the wing root to GAP 26.
I am going to change 1 of the molex from a 9 pin to 12 pin to add room for the GAP 26 Power, Ground, and Discrete. The Common fuselage harness will need to be changed to a 12 pin as well, but ill do this when I am mounting the wings, because I think those lines will be need to be shortened anyway. The common fuselage harness does have a 14AWG line coming to the wing root that the power will go into but the Ground and discrete have to be run up to the panel.

The molex that I'm going to change out.

What a 12 pin looks like.

Enlarging the mounting bracekt.

Running the Ground and Discrete wires.

Ground and Discrete.

Installed some cable protection.

and an edge grommet for the lines making the turn down into the pito mast.

Took off all the shims and parts and primed.

GAP 26 15.5 Man Hours