Drill a wire conduit hole in a closed wing

[flickroll]

How does one go about drilling a hole for a wire conduit in a closed wing? I have an RV-8 that I want to add some additional wires to the wing tip and the existing wire hole is too small. Looks to me like I need a long drill bit to enlarge the existing hole. Other ideas? Where would I get such a bit?

Thanks

Jim Shannon

[N941WR]

Jim,

I had to drill a 2nd hole in the ribs for my AOA line after the wing was closed.

To do this I used two drill extensions and a uni-bit. I had to grind down the head of the bit extensions so they would fit through the holes but it worked out.

Granted, it was a pain to re-install the uni-bit and extension as I moved along but it wasn't difficult. Oh, I also used a Pneumatic angle drill to turn the bit when I got into wing.

[jsharkey]

I added an aluminum conduit using 1/2 x .035 6061-T6 tube Adel clamped to the ribs at the accessible root, tip and aileron bell crank mid section.





Jim Sharkey
RV6 - finishing up

[flickroll]

Bill. how did you get the unibit in the extension? The shank of the unibit is way larger that the hole in the drill extension that I have.

Jim

[tommylewis]

I did this with several extensions and bought unibits from Harbor Freight, item 91616-9HZH, for $9.99 and then filled the base down until it fit in the extension. It worked and then I tossed the cheap unibit.

[Transporter]

Avery sells extensions in 6" and 12" lengths...they can be combined for additional length. No mod to Unibit required.

http://www.averytools.com/p-533-6-12...xtensions.aspx

Good luck,
Mike

[N941WR]

Originally Posted by flickroll

Bill. how did you get the unibit in the extension? The shank of the unibit is way larger that the hole in the drill extension that I have.

Jim

Jim,

My unibit fit the extensions w/o modification to anything other than the extensions.

Tommy's idea of using cheap bits sounds like a good one.

[fl-mike]

Two pieces of 1/4" threaded rod, two couplers, one drilled/tapped for a setscew. Put unibit in coupler and secure with setscrew. Use one rod and guide into existing small holes with free hand initially, then add second rod as you progress. Use low rpm obviously. Piece of cake.

[Jim Percy]

I ground the drive end of my unibits into a hex (they come with only 3 flats) which lets you fit it into a socket. Get a hex-to-square adapter for the drill end, then you can mix and match socket extensions as needed.

[flion]

Take your unibit to the Electrical tool section of Home Depot and match it's shank to one of the conduit bit extensions they will have there. One of these 36" flexible extension should do the trick.