Help with wing wiring, etc

Guys, since the empennage is all done, I am now waiting for my wing kit to arrive. I really do know nothing about constructing the wings (except what I have seen on the Orndorrf video). My concern is about the cable and pitot runs.

I am having the Vans 'system 6' lights with additional leading edge landing lights, an Evans Aviation pitot tube kit and an Angle of Attack Pro. How on earth do I plumb all this lot in? I have ordered the Vans corrugated conduit for the wiring so running out to the wing tips shouldn't be too bad. But how do I get wires to the landing lights; do I 'break out' of the conduit? If so, how? Or run another one? What?

Any advice you might be able to provide would be eagerly sucked up! Or point me to a web resource if one exists that is easy to understand.

Thanks,

Jeff, sorry to say but you wasted your money to get the corrugated conduit for your wings. I did too. It's too big for the size holes that Van's says to drill for the conduit. It's designed for runs in the fusalage. What you need is the black vinyl tubing that you get at landscaping places for water line drip systems. It's smooth and slips right in the holes. As for the wires, you need a power wire for each device that you install and a common wire also. The common wire can be just one wire with all the devices tied to it ( also known as the ground wire) or the airframe can act as the ground. I plan to use one ground wire connecting all my devices to a common electrical ground point instead of the airframe ground. Hopefully that will help eliminate any electrical noise that might occur. I will probably break out of the conduit for my heated pitot but where the landing lights are, I'll just go to the end rib, run the wires back through the ribto the landing light and use a small clamp to hold them. Mike 8 wings

One other trick...

When you decide what wires you need to run (and the previous post is a good list), run them - plus a piece of string! This way, in a couple of years, when you decide that you need some sort of "flux capacitor" or "quantum singularity generator" out on the wingtip, you can pull the new wire through with your already-in-place piece of string....

You just never know what goodies are goign to come along in the future!

Paul
(with strings in both wings and the vertical tail...tail-cam anyone?)

Well...I wouldn't say it's a waste:



The diameter called for by Van's is correct and is completely intentional because it 'traps' the conduit in place. The size called for is just a little larger than the smaller OD of the tube (there are two outter diameters since it's corrugated). There is no way in the world it's going to move. Yes, it's a bear to get it in there, but once you get the technique down it takes no time at all. The trick is to start in the middle of the wing. If I had to do it over again I would use the location recommended by Van's in the FAQ.

I used the same stuff in my tailcone and so far I'm very happy with the results. You can see in the fuselage that I dabbed some RTV on the conduit as the bulkheads to help ensure that it's not going anywhere.

Hmm... I used the corrugated conduit in my wings and it fit the holes fine. No complaints. Even running it after the wings were skinned was no big deal. I also like the corrugation (is that a word?) holds it in place in the holes and a little RTV secures it just fine. I ran strings through it and sucked it at one end with a vacuum cleaner so pulling wires is nbd. I'm sure other options are fine too.

I got a tip from somewhere to use a hair dryer on the corrugated conduit during installation in the 3/4" holes. It worked very well at changing the job from a nearly impossible threading through the rib holes to simply tiring. I did start in the middle and I did use the placement from Van's FAQ mentioned above.

Film at 11:00....

http://websites.expercraft.com/rzbill/index.php?q=log_entry&log_id=7875

Breaking out

Thanks guys for all your responses. What is the best way to break out for the leading edge landing light though? Just cut a hole in the conduit at that location, or go all the way to the end of the wing and then come back again with a new conduit or just the wires? (Thanks for the pics, by the way; and I had forgotton about the Vans FAQ; I've got the PDF on my computer here... somewhere...).

I can't say what the BEST way is, but for the landing light I just went to the outboard rib. For the TruTrak, I just cut a hole and dropped the wire (RTV around the hole).

If you really want to go first class, you can buy these things....



You can find them at -

http://www.cableorganizer.com/wire-loom/wire-loom-tees.htm

I'm not sure I'm going to use them, but they look neat.

Dave

Ooooh, now I like those! I wonder how heavy they are....

Thanks, might look into that...

I found that using the corrigated Vans conduit was cheap, light, and simple.

A trick that worked for me to get it through the holes was to stretch the conduit which reduced it's diameter enough that it gracefully slid through the holes that were cut to the size Vans recommends. I RTV's and tiewrapped the ends. For the pitot wires I cut an oval hole in it that was large enough that the wires exiting it would not touch the conduit hole edge. For the rest of the wires I made a harness of all the wires and cables going to the wing tips and pulled it through with a string (put in with the vacume method). Additional antenna cables were put through plastic snap bushings. No need for conduit on these.

Something about running a ridgid conduit through the wings just didn't seem right as I'm sure the wing will have some flex in it...but I'm not an engineer so that's just my best thought on it.

Mike R.

I thought I might cut a hole in the side of the conduit where I need to break out lines for the pitot and leading edge lights and insert a rubber grommet to cover the cut edges and protect the wires. I'll see if that is feasible when I get to that point.

I'm frustrated at the moment because I have finished the emp and I won't get my wings until early Feb, since they don't even ship from Vans until 16th Jan.

Wing conduit

I have just about finished my wings and used the method outlined in the Ornoff videos with the thin walled PVC pipe, worked out fine and I plan to put straight couplers on each end which will hold the pipe in place and provide a smooth exit for the wire bundles. My current set-up is dual duckworth landing lights and the Van's/Whelan strobe/lights and I plan to run the wiring out to the wingtip and back to the landing lights (they are in the outermost bay) and make the wingtip removable. There are threads here about disconnects versus no disconnect connectors, your choice.
In my setup I plan an archer antenna in the left tip and aileron servos and AoA sport in the right wing and all the input I have received says this wiring will all fit in the PVC pipe.
Dave

exit holes in conduit

For making exit holes in whatever plastic conduit you have, has any one tried poking a hole in it with an old unloved soldering iron? Preferably without the wires in it, and definitely on a piece of scrap first. I haven't had need to try it yet, but it seems like it would work (and stink) and take care of the rough edges at the same time.
Johnny

Corrugated conduit

Has anyone had any luck installing Van's corrugated conduit in QB wings? Has anyone found what works best to drill the holes in the inboard ribs (where the skins are already attached) to accomodate the conduit? I thought I'd get some advice before trying ......... I could always use light-gauge PVC pipe/tubing through the lightening holes, but I would prefer to use the corrugated stuff ............ I think.

QB wings and conduit holes

I just did this last week:

http://www.rv7blog.com/index.php/2006/01/02/wing-wiring-holes/

Making a little drill template helps a lot as far as locating the pilot holes. You should be able to drill all the pilot holes in the inboard-most ribs using a small-diameter 12" drill bit. For enlarging the holes in the wing walk ribs, I used a 12" drill extension from Home Depot, and for the other ribs that are already skinned in the QB kit I used an electric angle drill with a 3/8" chuck that I borrowed from somebody at the airport. Wiggle it up through the access panels and drill the ribs to final size. It's tight but it can be done.

Good luck,
mcb

simple conduit

Since your building the wings yourself you might like this idea. I built a jig (a 1/4 inch piece of plywood with two holes to put bolts thru the tooling holes of the ribs) so that the 1" hole I drilled would be in the exact place on every rib. This allows you to shove a pice of 3/4 inch thin walled pvc pipe down the entire length of each wing (see picture). I used a unibit to drill a hole for the heated pitot wire mid way down the wing for wire exit. The nice thing about this method is you install the pvc pipe after the wings are on the airplane and the wires easily pass down the smooth inner surface. This is the method I used on my RV-6 and now on my 8A.