[pmccoy]

I am thinking about wiring my wings, and have searched and read a few threads on making wire connections at the wing root. It seems people are using AMP CPC connectors, terminal strips, molex and more. I am also considering wiring in a connector at the back of each side of my removable panel. That would allow me to pull the panel for maintenance going forward.

Several of the connections in my wings do require a small amount of power to drive lights and servos. No circuit is more the 4.5 amps, but all totaled up it could be as much as 11amps if everything was on at the same time.

Looking at CPC, the spec sheet say's this is for signal wire only. No power.

Molex allows power, but I have been told are not good if you plan to plug and unplug more then just a few times, which shouldn't be a problem in the wing root.... but makes me wonder on the panel option.

Terminal strips seem to allow open electrical connections that run the risk of having a conductive object get inside the cover and possibly shorting out a circuit.

Yikes, what's a builder to do??

Any ideas on how to make wing root connections would be appreciated. Thanks.

 

[frazitl]

I used these

for the higher current loads (light, pitot heat, etc.) note: be sure to copy the whole link. (http://order.waytekwire.com/product...ulti-Pin Connectors/Terminals And Connectors/

Good company to deal with. They do have minimum order quantities, but the prices are really reasonable.

For the trutrak servo, I used Dsub 9 pin connectors and they are working fine so far.

All my connections are inside the Fuselage under the fwd removable panels.

 

[apatti]

Terry,
How are wires connected to the connectors? Do you need a special crimper?

 

[rjaflys]

wing root connectors

I used the knife connectors ( I'm sure thats not the technical name)that are used in certified aircraft. These are the ones that you put together at 90 degrees and they lock when you straighten them out. They work well if you only have a few wires that need to be connected, and will carry enough current for servo's, etc. They are insulated by a short piece of tubeing held in place by small tie wraps, or you could use heat shrink insulation.

 

[frazitl]

typical crimping tools for molex connectors worked fine. I didn't spring for the special tools from Waytec. Try the generic Molex crimpers first.

 

[LettersFromFlyoverCountry]

Originally I was going to have connections at the wing root but decided not to. I've seen terminal strips on the wing root rib, which makes no sense to me. There's very little room to work in there.

I was going to use Molex connectors and decided not to do that either when it finally came time. Why? Why would I want to? Is the idea that i can take the wings off? Putting the close-tolerance bolts in last week disavowed me of any intention to ever take the wings off. Is it possible it could happen? Maybe? But I'll bet the odds of having a failed connection in the wiring are better.

In the end, I ran string through conduits and as it came time to mate the wings, I pull the wires through and left a little extra. If I should need to take the wings off, I can cut the connectors at the device, and still have plenty of wire to put them back on later. No point of failure. No extra weight. I ended up saving time.

YMMV.

 

[ChiefPilot]

I used the knife connectors as well, with heat shrink tubing over them.

My reasoning was that I may want to disconnect them at some point, but doing so is unlikely. I didn't like the terminal strip idea for complexity/failure potential, and didn't like the molex route because of the bulk - it just didn't seem very easy to secure it in such a way as to be able to unplug it easily while preventing it from flopping around. The knife connectors were inexpensive and are an approved solution, so it was an easy choice for me.

 

[erich weaver]

Im with Bob on this one. No connectors at wing roots means fewer parts, less complexity, and reduced failure rate. KISS principal in action

erich

 

[pmccoy]

Thanks to all for posting your thoughts. Now I have to decide which way to go. In the end, I may end up not installing anything. As was mentioned, who knows if the wings will ever come off again?

 

[Mike S]

In the 10 I am using....

As above, a mixture of knife connectors, D-sub, and Molex.

A word of caution about the knife splices----be sure to label each wire, these connectors are unisex--- any one of them will hook up to any other.

I mounted the D-sub to the fuse , and a pigtail from the wing to hook to it.

Molex for the strobe, for the ease of keeping the polarization correct.

I did spend the $$ recently for a ratcheting crimper from Stein, wish I had done so a long time ago. Good tool, and well worth the money.

 

[Fearless]

I am debating this myself. The only thing I want to add to is what Mike said about the crimper. I bought a Daniels crimper with positioners off Ebay and it is the only way to go if you are working with Dsub connectors and pins. It will pay for itself by the time I finish with my wiring.

 

[bcondrey]

Just an FYI for those considering connectors. There are multiple types of AMP CPC. Series 2 uses the same pins as normal dsubs and would do fine for the AP servo (the servo itself uses dsub connectors), nav lights, etc. There is also a Series 1 with much higher current handling abilities. These need the same crimpers as Molex connectors. Current handling is sufficient for landing lights, pitot heat, etc. There are a variety of pins for these and are sized based on ranges of wire size.

Bob
RV-10 N442PM

 

[Mike S]

I am debating this myself. The only thing I want to add to is what Mike said about the crimper. I bought a Daniels crimper with positioners off Ebay and it is the only way to go if you are working with Dsub connectors and pins. It will pay for itself by the time I finish with my wiring.

Actually I was talking about this crimper.

But, you are right about the D-sub pin crimper also being a "must have" tool. And the insert/remove tool also.

 

[Rick6a]

....who knows if the wings will ever come off again?

Removing the wings was never a consideration when I chose to install wing root connectors. It is a generally agreed upon point among builders that you will accomplish more work at home than you will at the airport and I've done it both ways to understand the wisdom behind that thought. The second time around, my priority was completing as many tasks as possible while the airplane was still at home in my garage. Thanks to prewiring and checking all electrical systems BEFORE the airplane was moved to the airport, simply "plugging in" all the circuits via mating receptacles made very short work of the electrical portion of final assembly. I do not anticipate ever having to remove the wings but if I do, there should be no problem disconnecting the various circuits or later having to remember which wire goes where.

 

[Fearless]

I got that one from Stein as well. Match the color to the connector and go.

 

[kentb]

A couple of thoughts for you Peter

I use D-9 connectors for signals and molex for power (lights, strobes).
I thought that I had a clever system. During final assembly I had the first wing half installed when I realized that I had forgot to plug in the connectors.

There is no way to get your hands in between the fuse and wing to connect or disconnect those connectors. I had to remove the wing about six inches and then hook up the connectors. I just doesn't serve and purpose to have a connector where you can't use it.

I would recommend leaving 1 to 2 feet of wire sticking out of the root and pass that through the side of the fuse. You could put your connector under the seat or just crimp the wires together at that point leaving some extra for maintenance in the future.

Kent

 

[Mike S]

Guess us 10 builders are spoiled.

Plenty of room between the wing and fuse for making up the wire connections, and the wing attach bolts are out in the open.

 

[Rick6a]

There is no way to get your hands in between the fuse and wing to connect or disconnect those connectors. I had to remove the wing about six inches and then hook up the connectors. I just doesn't serve and purpose to have a connector where you can't use it.....Kent

Kent,

I must respectfully disagree. With a little planning, there is no need "to get your hands between the fuselage and wing to connect or disconnect those connectors." The gap in the -8 series was wide enough for me to get in there with my (large) hands but if not, I would have incorporated a simple "service loop" in the wing root wiring to make those connections.

 

[Bob Axsom]

I also support Bob's approach

In the end, I ran string through conduits and as it came time to mate the wings, I pull the wires through and left a little extra. If I should need to take the wings off, I can cut the connectors at the device, and still have plenty of wire to put them back on later. No point of failure. No extra weight. I ended up saving time.

YMMV.

I wired every thing and coiled wire at all major assembly interfaces. When the instrument panel was installed and the wings mated I butt spliced the the wires as a permanent installation with service loop at terminations. When the checkout was complete the wiring was in final high reliability form with proper point to point wire gauge and no friction fit electrical resistance or potential failure points. I remove tip tanks and tips with lighting for races and out there I use knife splices. They must be carefully marked for correct hook-up. They work but they change friction fit with repeated usage - they get pretty loosey-goosey and have to be reformed for good continuity over time with repeated assembly and disassembly.

Bob Axsom

 

[sjjonesnz]

I used Molex connectors for power (nav lights, strobes, pitot tube) and a d-sub connector for the autopilot. For obvious reasons I'm hoping the wings don't have to come off, but I feel it made it all just that bit tidier and easier.

Access to the connectors so they could be mated after the wings were installed was through the aileron pushrod holes...had enough length in the wiring to make that easy as well.

 

[prkaye]

I've seen terminal strips on the wing root rib, which makes no sense to me. There's very little room to work in there.

I put terminal strips on each side, under the the floor between two ribs. I made mounting platforms for the terminal strips... these attach to the ribs on either side and run between them, allowing the terminal strip to sit horizontally beneath the floor panel, above the bottom skin. My forward floor panels (the ones that go over the control sticks) are removable with screws/nutplates, making easy access to the terminal strips and the control column assembly. THere's tonnes of room, because hte terminal strip is mounted horizontallyThis worked beautifully for me. I like this over a big connector, because each wire goign to the terminal strip is clearly labelled and individually accessible. WHen I built the wings I left the wires coming out of the wings a little long and un-terminated. WHen wiring the fuse, I just terminated the connections to the wires with ring terminals and connected to one side of the terminal strips. After plugging the wings in, it took me very little time to cut the wing wires to length, crimp on ring terminals and connect them to the terminal strips. It's neat, and everything is clearly laid out and accessible.

 

[N427EF]

connectors

Here is another option.
I like to use the amp connectors for the large wires, landing and taxi lights, strobe and nav lights. The amp connectors are keyed .
For signal wires like autopilot and trim servo the d-sub are just right.
Less connectors is probably better but I like to tidy things up and finish the wiring in the fuselage and likewise in the wing so when the time comes to assemble the wings and the fuselage all has been tested and finished, at least that is what I do before taking the plane to the hangar. There is enough loop in the harness to conveniently connect the plugs and stow them away in the first bay of the wing, securely zip tied to the wing structure.