Wires

[DesertFox4]

Nice work Andy.

[Flybyjim]

Yes,
Looks good, For simple aircraft there just seems to be a lot of wires!

[n85ae]

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

[jrevens]

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.

IMG_1411.jpgIMG_1413.jpgIMG_1414.jpg

[n85ae]

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

[t j]

Get a hard copy of AC 43.13-1B

"Chapter 11. Electrical Systems
ON line here http://www.aeroelectric.com/Referenc...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]

Jeff- thanks for the tips. Makes perfect sense.

Tom- I appreciate the link.

[jiott]

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]

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]

Thanks, all good info