Trevor & Dewey's RV-7 Construction Log

Wing Jig

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November 18 & 25, 2009

Main Wing Jig

We spent the evening building the wing jig. It was made with 2x4's and screws.

Here are 27 - 2x4x8's and 4 - 2x4x12's.

We made the ends first. All the horizonal and vertical members are made of 2 2x4's screwed together. 4x4's are can go out of alignment very easily, so the general consensus is that 2x4's are to be used.

We then put the ends up and screwed 4 2x4x12's into place on the top and bottom. The distance between the inside of each vertical post is 114" as called out in the wing drawings. The horizontal distance end-to-end is 48". Most jigs I'd seen allowed 36" between the wings. I thought this might be too close and wouldn't allow enough room for us to buck rivets and maneuvers skins in place so it was increased to 48".

I then cut 1"'x1"x1/8" angle into 15" long pieces for the main spar support (see last picture). Smaller pieces were cut for the support mounted 14" below the main support. Lastly, I cut 1"x1.25"x1/8" angle for the rod supports. I have 3/8" rod that will be used to level the mail spar support. These pieces are 1" wide.

I then marked and drille 1/4" holes on the smaller side and 3/8" holes on the larger side for the rod.

Below is the almost completed main spar support. The upper channel is 15" long and bolted to the jig with a single 1/4" bolt. The shorter channel is mounted 14" below with two bolts. The small channel pictured above are mounted at right angles to the upper and lower supports. A 16.5" 3/8" rod will be used to keep the upper support level. I would have finished it today but the rods I originally purchased were too short! Off to Aircraft Home Depot.

After making a trip to Aircraft Home Depot, I purchased 24" 3/8 rod. I first cut the rods down to 18" with a die grinder and ground down the edge with a grinder to smooth out the threads.

Using 4 nuts, 4 flat washers, and 2 lock washers, I secured the rod in place. I first tightened down the top part of the rod so I could control how many threads stuck out (so they don't hit the spar or associated wing parts). I then adjusted the bottom nuts to get the upper spar support level.

0.0 degrees, thats pretty level!!

Left spar marked and clamped in place (temporarily).

Both sparts in place and level! They are starting to look like wings! (okay, maybe not quite yet).

Leading Edge Cradle

I then used a W-709 rib as a template to make the leading edge cradle.

Wing Cradle

I then used the same nose ribs to mark the particle board for the wing cradle.

After building the wing cradle I flipped it over to secure the casters.

Done! It fits so nicely in the middle of the wing jig!