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Flybyjim
07-21-2014, 07:09 PM
This will be my third plane that I will have built and the other two have been fun to build but I have never been satisfied with the wiring. No matter how much I plan it seems I have a mess. What are good sources for this problem

DesertFox4
07-22-2014, 03:05 PM
Jim - maybe some will share photos of their behind panel wiring layouts to show how routing and planning can clean up the wiring installation.

I love a cleanly wired panel and hope to do much better on my 7SS than I did on my 4 although my model 4 has worked flawlessly. Some of the builders on here are over the top skilled at wiring including the factory built Kitfoxs.

akarmy
07-22-2014, 04:22 PM
Hi Jim,

Check out the pictures I have posted of my Series 7 at this link.

Wiring pictures gallery (http://www.teamkitfox.com/Forums/album.php?albumid=143)

http://www.teamkitfox.com/Forums/picture.php?albumid=143&pictureid=1761

You didn't say where your questions are?

I used only aircraft tefzl wire, tried to support it at any location where it can rub on structure. Label each wire so you know where it goes if you have to troubleshoot it later. I used an automotive blade fuse block to make power distribution easy. Then just wired it up one wire at a time. I used black zip ties to hold everything in place. Just put them on loose at first, then cut them off if you get too many wires going through a location. When you are done you can put new zip ties on to secure the bundles or on my current project I went back and laced the wires with waxed string to replace the zip ties.

If you have other questions ask away. Good luck with your project!

DesertFox4
07-22-2014, 08:02 PM
Nice work Andy.:)

Flybyjim
07-23-2014, 04:21 AM
Yes,
Looks good, For simple aircraft there just seems to be a lot of wires!

n85ae
07-23-2014, 08:26 AM
I used to do this for a living, the secret is VERY simple, but NOT many people
seem to understand the concept.

I use old copper house wire to make temporary bundle guides (like fishing rod
line guides), where the bundles should logically go. These are used to rough
route the wires.

Basically the key is to route wires first, cut them long (2-4 inches) but NOT
connect them. Then using masking tape, wire, string, etc. Make everything
look like you want. Tie it down, I use Adel clamps to connect to the airframe,
and waxed dacron lacing tape to bundle the wires. After the bundles are then
nice and neat. THEN terminate the ends and hook up the gear.

DO NOT hook up wires, and try to string them one by one, you will just end
up with a big mess. This is how most people make a mess in my opinion.

Regards,
Jeff Hays

t j
07-23-2014, 08:40 AM
Get a hard copy of AC 43.13-1B

"Chapter 11. Electrical Systems
ON line here http://www.aeroelectric.com/Reference_Docs/FAA/AC43.13-1B_Ch11_Electrical.pdf

Look through all 12 sections in this chapter. Everything about proper aircraft wiring techniques is in there. You will be surprised at the good information and probably important things you didn't know about wiring an aircraft.

My favorite sections:
Section 10. Service Loop harnesses

Section 11. Clamping

Section 12. Wire Insulation and lacing String Tie
I have been progressively replacing the plastic zip ties in my wiring with wire lacing string. It takes longer to install but is much nicer in my opinion. I can reach behind the panel without drawing blood now.

DesertFox4
07-23-2014, 11:57 AM
Jeff- thanks for the tips. Makes perfect sense.

Tom- I appreciate the link.

jiott
07-23-2014, 04:40 PM
One thing I found very handy for bundling wires in the longer runs like from the tail cone to the console and the console to the panel was lightweight plastic 1/2" sprinkler pipe (lowest pressure rating like 100 psi I think). I slit the pipe lengthwise to easily get the wire in and out at various points along the run. The slit would close back up and contain the wires quite well. At some points along the run I would put some zip ties around the slit pipe to attach it to the frame and keep the slit closed if needed. I even ran some of my pitot and static tubing inside this pipe. It is really lightweight and gives very good protection to the wires.

DesertFox4
07-23-2014, 04:43 PM
Jim, I used that on my model 4 and the 7 SS. Makes running wires from the console to the tail easy. Also great for future wires if needed. Very lightweight.

Flybyjim
07-23-2014, 07:46 PM
Thanks, all good info

War Eagle
07-30-2014, 02:01 PM
Hi Jim,

I used only aircraft tefzl wire, tried to support it at any location where it can rub on structure. Label each wire so you know where it goes if you have to troubleshoot it later. I used an automotive blade fuse block to make power distribution easy. Then just wired it up one wire at a time. I used black zip ties to hold everything in place. Just put them on loose at first, then cut them off if you get too many wires going through a location. When you are done you can put new zip ties on to secure the bundles or on my current project I went back and laced the wires with waxed string to replace the zip ties.



This is what I did also. I labeled each end of the wire using white shrink tube and wrote the name and polarity on it with a fine point permanent felt tip marker and then I would heat shrink the tubing. The label is very nice looking, won't tear off and can be very easily read when needing to do trouble shooting.

n85ae
07-30-2014, 02:08 PM
The irony is that the more careful you are to label everything, you will likely do
such a good job wiring, that you will never have the need to troubleshoot
anything ...

Jeff

Dave S
07-30-2014, 02:16 PM
"you will never have the need to troubleshoot
anything ..."

Jeff - I think we can live with that!:)

Dave S

Danzer1
08-26-2014, 01:23 PM
There's a good article on panel wiring in Kitplanes this month - very thorough too.

Greg

jrevens
03-03-2020, 08:56 PM
I frequently hear builders preaching the superiority of lacing wire bundles with waxed cord vs wire ties. I used wire ties exclusively on both of my homebuilt airplane projects, & they do have some obvious advantages over lacing... for instance, if you ever want to add wires to a bundle, lacing can be a PITA. They are also much faster to do, and the "sharp edge" issue when cutting off the tails is a non-issue if the proper tool is used. Anyway, I had an opportunity to take a tour through the new Pilatus Aircraft completion facility at my home field (KBJC) today. They also do a lot of military work, but right now there wasn't any classified stuff going on so we got a good tour. They had several models being completed - avionics, interiors, etc. in various stages of completion. One of their PC24 jets had some panels open and wiring was visible. I found it interesting that they don't use any waxed lacing cord on wire bundles - just my favorite T&B brand wire ties. This is an $11.4 million airplane.

241702417124172

n85ae
03-04-2020, 08:17 AM
I use Wax lacing a lot, but simply because I was trained to use it in the Navy, and I can tie it really fast.
I also agree it is a PITA to cut off, BUT I don't have to do that often ... So I don't care. but I use Nylon
ties also when they're easy to install (like in one handed situations). FWIW if you get a nice pair of for
example Lindstrom flush cutters, they work really well for cutting wax lacing (the right tool for the job)
and working with it. Just don't look at the price tag when you buy them ... Also don't cut safety wire
with them ...

Not to be a critic, but ...

In the pics in the Album I do notice a few problems, and they are not neatness issues. More I see wires that
are floating off the end of crimp connectors. This is a recipe for breakage. You should tie all your wires, so
the crimped part is not supporting the wire. If you do that neatness to a degree does not matter. A really
good example what I mean is the splice which is tied to the airframe, BUT the wire off both ends is floating.
there is a really good chance the wire will break off this splice.

Also another rule is to make sure you always have a slight amount of "extra" length where a connector is.
Not much, but enough so there is never tension at the connector. If possible all your wires should be tied
within 2-3" of a connection. Never floating.

Jeff

jrevens
03-04-2020, 09:17 AM
Great points, Jeff! I think I can see the places you’re talking about. There are a lot of crimped connectors/terminals where the wires are secured to neat little arms that come out from the base of the connection points. That may not be very clear in the pictures.

Also, I sure didn’t mean to be as negative about lacing as it seems (even to me) from my comments. I think it’s still the “gold standard”. I was just a little surprised to see how Pilatus did it... even using the very same brand of ties that I like to use. Guess it seemed like a little bit of vindication for my laziness. 😉

n85ae
03-04-2020, 09:43 AM
No worries, I got out of the Navy a million years ago. I was an Aviation Electrician's Mate
and worked on Grumman E-2C's, I was the shop QA inspector, so I'm still nitpicky about
wiring.

This is the kind of stuff to avoid. Wires are floating off the crimp, and the wire will vibrate at
the crimp, work harden, and break. I would tie the wires each side of the crimp, and let the crimp
float if anything.


24173

efwd
03-04-2020, 02:52 PM
Awe, perfect timing. Fixing to start putting the plane back together. I need to address some issues. Thanks for the post John. It has drawn out some wisdom that I can use. Thanks Jeff.

n85ae
03-04-2020, 04:32 PM
Sorry to add more work, I'm waiting on my fuel pump to come back from the shop, and my exhaust
to get back from the welders. There's no winning ... I'm wondering now after all these years if when
I installed my exhaust whether there was any binding that later led to cracks ...

Seems everything in the plane with an "O-Ring" in it is leaking as well ... Fuel drains, valves, etc. (I only
run Avgas, but this is 16 years since I built it ...

Jeff

jmodguy
03-08-2020, 10:09 AM
For what it’s worth, hardware store splices do not belong on an aircraft. See Jeff’s pic above. The coatings on the Tefzel coated wire strands are sensitive to moisture. I have seen entire spools ruined due to moisture penetration of the wire via an unsecured end. You should use environmental splices that have wax sealing plugs on both ends of the insulator.
I was in the Navy as well wiring EP3s for 20 yrs. We used string tie as well as plastic zip ties. Either will work but do cut the zip ties flush with the clamp or you will regret it one day! Do NOT use wax string that is made with bees wax. It is organic and can/will mold.
As a certified IPC/WHMA 620 Instructor, a good reference for terminating wires is the IPC/WHMA 620 manual. This doc defines criteria for Class 1, 2, and 3 interconnect terminations, securing harnesses and many other harness needs. It is not cheap but it will tell you what it should look like when you are done.