Wing Attachment & Rigging

"Where were you when I laid the foundations of the earth?
Tell me, if you have understanding.
Who determined its measurements?
Surely you know!
Or who stretched the line upon it?
To what were its foundations fastened?
Or who laid its cornerstone,
When the morning stars sang together,
And all the sons of God shouted for joy?"

Job 38:4-7

Hey Scott

I used hardware store bolts through my spar when I fitted my wings. I polished them up on the scotchbrite wheel and used Boelube.

For drilling the rear spar, it wasn't a big deal. I drove the drill while my buddy eyeballed the angle of the bit (top and side). Edge distance shouldn't be an issue. I had all kinds of edge distance left after drilling.

We got the wing square and at the correct incidence (and checked about 400 times) then used C Clamps to hold the rear spar in place. I pilot drilled with a 3/16" bullet bit (Black and Decker), then used an "N" size drill bit. Once that was done, I used a high quality 5/16" reamer to finish the holes.

That's it.

Cheers

drilling rear spar & wing mount

I'll post my experience with drilling the rear spar in hopes it will save you some hand wringing.

First off mark the rear spar edge distances on all parts (5/8" I think). This way you can visually see if things will work. You will have a 'box' that is safe to drill in on all parts.

Next get the wings in place with a few junk bolts tapered to fit. I used a C clamp vice grip with flat feet to hold the rear spar during the measuring. Measure everything by the book.

You are likely to have interference with the rear spar parts that cause your wings to sweep forward. Mine was with the wing rib flanges and the forward 'fork' in the -6A fuse. Look carefully at what needs work and trim to fit. A little sweep is OK per Van's - but try to make them equal. Your wings will go on and off a few times while doing this, but only need to slide out a foot or so to do the trimming.

Next make alignment marks (vert & horz) for the rear spar since you will need to move your vise grip out of the way, and you want to still hold the wing in the right place. I gripped just the edge of the rear spar with the vice grip which gave me a spot to drill.

Now you are ready to drill. Make yourself a wood block drill guide to be perpendicular. I didn't and wish I had. Now my bolts have wedge tapered washers. Then drill it per the book.

If you are taking the wings off again, don't forget the other things that must be done: Fuel tank mounts, root trim fit and drilled for nutplates, flaps fit to fuse and flap rod holes cut, all plumbing lines and wiring figured out, cutting control rods to length, etc. YMMV - every model is different.

Nothing special about rigging control surfaces that I can think of - didn't seem hard compared to the wing mounting.

Kelly
RV-6A tipper finishing
PHX, AZ

rv8bldr said:

Hey Scott

I used hardware store bolts through my spar when I fitted my wings. I polished them up on the scotchbrite wheel and used Boelube.

For drilling the rear spar, it wasn't a big deal. I drove the drill while my buddy eyeballed the angle of the bit (top and side). Edge distance shouldn't be an issue. I had all kinds of edge distance left after drilling.

We got the wing square and at the correct incidence (and checked about 400 times) then used C Clamps to hold the rear spar in place. I pilot drilled with a 3/16" bullet bit (Black and Decker), then used an "N" size drill bit. Once that was done, I used a high quality 5/16" reamer to finish the holes.

That's it.

Cheers

Click to expand...

Did mine the same way(also ground the bolts down to a slight taper) and it turned out well. Definitely a "butterflies and sweaty palms" procedure. Remember to measure one last time before drilling.
Good luck.

Check out the FAQ Link on Van's website. There is a very informative pdf on wing allignment there. Gus at Van's said the incidence is the least important of wing sweep, 5/8" minimum & triangulation to the tail per a friend of mine building a 9. If the incidence is off, you re-shim the HS.

Derrell
RV7A

Scott,

The Discovery Wngs "from the ground up" video series is excellent for tips and covers quite extensively the wing attachment. I think its video number 3. No need to buy the full series which covers the building of an RV8 at the EAA HQ workshop.

Matt Hurley

taper wedge washer

Where did you get the taper wedge washers? I could use some.

wing dolly

I found that an old office chair with the back removed makes a real nice wheeled dolly for helping to support the wing while manuevering it into the fuse. Even the cheap ones have a hydraulic up-down adjustment that came in real handy.