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How to drill the inboard ribs of QB wings to install conduit?

Westerhuis

Well Known Member
Patron
Hi

How does one dril the inboard ribs on QB wings to fit the Van's supplied conduit? With that part of the wing already skinned it looks impossible, but I am sure it can be done. I'd have to drill holes up to 3/4". What tools do you use? Going through the two inspection holes is probably the way forward? But that still leaves little if no room to actually cut the hole?

Not sure if the ribs on more modern kits have a tooling hole, or a pre-drilled hole on the spot Van's recommends for this? But my ribs have neither.

Some images to show how it's done would be useful.

Many thanks!

Rogier
 
Hi Rogier,

just recently drilled the holes on QB wings. On the outer ribs you can use a smaller drill with a step drill attached to it. On the inner ribs which are already covered with the skins I used a self made extension. See pics:

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An alternate idea. I used Adel clamps to secure conduit through the existing lightening holes
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⬆️ I did the same thing with the step drill and home made extension. I made the hole big enough for a snap bushing with a 1/2” ID that fits my “conduit”. The conduit is actually a type of wire wrap I picked up at an industrial automotive hardware store here in Cincinnati. It slides nicely through the snap bushings in the wing ribs. The nice thing about that is you can pull wires out mid stream in the conduit run for things like pitot heat or a temperature probe. This type of conduit is slippery inside and easy to pull or even push a wire through it all the way to the wingtip. I have a pull wire in each wing just hanging loose in case I want to add more wire later.

 

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As others have mentioned or shown, Unibit on an extension HOWEVER be sure to protect interior skin from a dropped tool, lay a towel or something in each bay. Removing fuel tanks offers more options too.
 
Just running the conduit in the big holes and attaching them with zip ties is an option.

 
I have a -7 built without any wiring. I used pvc, adel clamps, and Boeing standoffs to add a conduit for wiring in both wings.

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Edit: Should I ever need to replace, or add a wire. No big deal.
 
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