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Don Lindsay

Member
OK, how *do* you run wires inside a QuickBuild wing?

Van's has a FAQ suggesting I drill the wing ribs for a 3/4" plastic wiring conduit. But with a QB wing, half the ribs are already under skins. Working on those ribs looks difficult. Putting Adel clamps by one row of lightening holes might be less drilling, but it's still tricky drilling, yes ?

I do have snap bushings in the ribs. There's 1/4" bushings down both QB wings, and 3/8" bushings down the left wing. Is that really enough? I mean, adding up all the things I've heard of in wings, the list is:

- VOR antenna (coax, yes?)
- pitot air (1 wing only)
- tip light power
- landing light power
- strobe power
- pitot power, if it's electrically warmed (one wing only)
- wing-leveler servo (one wing only)

It's not all gonna fit in 1/4" !! Not to mention I'm supposed to keep antennas and strobes well apart...

So what have other people done?

Don
RV-9A
N255RV reserved
 
The holes in the ribs of a QB are not large enough to get all the stuff in that most people want. Van's has an SB or SL that tells you where to put a larger hole - the problem is how to drill it. The ribs with no bottom skin are not that difficult, but as you point out the inboard ribs are more tricky. I used a unibit and a 12" long extension. The unibit has to have its largest step as the size of hole you require (3/4 IIRC), and the 12" extension will probably require the end to be drilled out (as the shank of the unibit is quite thick), there was just enough meat left for the socket headed screws to engage in. I think I put a pilot hole in first with a 12" #30 drill, but it was a couple of years ago.

The real game is trying to force the corrugated black plastic tubing through the holes! If I did it again I might use regular water pipe and accept that it weighed a little more.

Pete

PS if you use individual strobe power packs in the wing tips there is no issue about keeping the strobe & antenna feeds separate.
 
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Just got done with this. I used pvc pipe. I decided I can live with the extra weight, which honestly isn't that much. Take a look here.

What the pics don't show is that I used Adel clamps on the root rib, a rib at the mid access panel, the inboard-most rib accessible via the outboard access plate, the outboard rib, and one in between those two. It's nice and stiff, and I should be able to get any lighting, radio, AP servo, camera, or any other type of wires down that thing with room to spare and ease of pull. I made the brackets from a replacement HS spar I didn't wind up using and made sure they hold the pipe off the lightening holes enough so nothing gets banged together with vibration.
 
Ah, the challenge, and the benefit of VAF. I scratched my noggin for about 3 months trying to figure this out during the preVAFic age (the time before VAF).

I used two 12 inch drill extensions and a unibit (7/8 inch max diameter) to go through the root ends and tip ends as far as possible. This set up let me get almost through the root ends.

The remaining ribs were done with the same unibit attached to a 40 inch flexible drill shaft from Sears ($35). Not the same quality as you'll get from an aircraft supply shop but, also only about 15% of the cost. With this, I was able to go through the inspection holes to get the remaining ribs. This setup can be a bit cuimbersome to operate with 2 hands. I found it takes 3-4 hands, 1 to hold the drill, 1 to hold the unibit and 1 or to to help keep the shaft from twisting. Go slow because the shaft will twist with a suprising speed and jolt if the bit jams.

I couldn't find a unibit that would fit the drill extensions and the flexible shaft so I was forced to buy the unibit and take it to a machine and tool shop to turn the shank down to fit the throats (another $35).

All up, this 1 issue cost me about $100 in tools. Of course, the tools do have other uses.

Drill the holes, snake the Vans conduit through and put a good bead of RTV on both sides of the ribs to hold the conduit in place.

The hardest part of this project (besides figuring out how to do it and getting the right tools) was deburring each of the holes.

Jekyll
 
Homemade extension

I took a long steel rod and coupled it to a unibit on which I ground off the last step to provide the correct diameter for some gray plastic electrical conduit. I ground a flat on the side of the steel rod (there was already a flat surface on the unibit. I took a piece of brass pipe that had a little larger inside diameter than the rod and the unibit shank and drilled two holes in the side (using a drill press) for tapping. Then I tapped the holes and used set screws regular screws with the heads ground off after assembly work fine) in the tapped holes to couple the rod to the modified unibit. I drilled the hard to reach ribs with this tool and when all the holes were drilled prepared the plastic conduit and inserted it. Part of the preparation is determinie if you need any side ports and if so where they need to be placed. I needed one around mid length for my pitot heat wires and one at the ends for the nav/ strobe/landing light and tip tank fuel sender wires. These holes need to be measured and cut before conduit insertion.

I found that I had to make several special tools during the building of my airplane and Van's should not be expected to tell you in the instructions how to solve every problem if the cost is to be kept reasonable. There customer technical support works fairly well to fill that need I think. After a while I had no reservations about grinding down the end of wrenches to allow me to accomplish a task in a tight space, etc.

Bob Axsom
 
I used the irrigation hose and drilled out a 3/4" hole for my rv10-QB wings. Avery tools sells a great extension with the socket head cut down enough to allow the 3/4" unibit room to do its thing.
Tom H.
 
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I also used PVC pipe from the Lowes aircraft department. 1.5in and with 4 Adel clamps -- one at each end and two more in the area where the skin is not yet attached. A small 90 deg angle is needed to be riveted on each rib to attach the clamps to. Agonized over this for a while thinking about drilling the ribs but this was cheap, easy and quick. Plus there is plenty of room for any wires that might be required. I put a fairly large hole in the area where the heated pitot and in my case the Dynon heated pitot controller are and it will be easy to run the wires. You should use thin walled pipe to keep the weight down.
 
wiring a qb wing

I used three 12 inch drill extensions and a unibit. Harbor Freight has some cheap unibits that worked well for this. I then ran the Van's flexible conduit through these holes. I had to do both wings as I had stuff in both wing tips. It worked well.
 
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