Section: 14
Hours: 4

First thing today Woody and I inspected the work from yesterday. Woody smelled out a few not so well set rivets. I carefully drilled them out and reset new ones.

My goto bucking bar for setting the AD4-7 rivets is the special RV-14 bar originally for setting some rivets in the elevator. I found this bar was massive enough to set the big rivets and easy to hold flat (I used the flat surface of the bar, not the special angle section that was ground for the elevator rivets).

After finishing the rework, I set the forward rivet of the rib tabs under the spar flange in the gas tank area.

This afternoon the torque meter I ordered from Amazon arrived. Section 5.20 of the manual says for friction lock nuts you must measure the drag friction and add that to the specified torque table value.  You run the bolt down to until it is 1 or 2 threads from being seated and then measure the friction. Here I'm measuring 12-14 inch pounds of friction drag which I will add to the 28 in.lbs. specified for the nut for a total of 42 in. lbs.

I used my torque wrench set to 42 in.lbs. to tighten down the bolt and then went back and measured the result. Looks like the torque wrench and the torque meter agree!

I began work on the rear spar assemblies at the end of the day. More heavy aluminum pieces with rough edges that need to be smoothed out and flattened.

Section: 14
Hours: 7

I went to bed thinking about the construction manual note - "Bolts MUST be installed oriented exactly as shown". This morning I double checked the drawings and noticed that several of the inboard most ribs have the bolts heads on the opposite side or half and half. Luckily I hadn't torqued anything yesterday so it was easy to reverse the bolt orientations to match the drawing.

I torqued the bolts and then set the rather long AD4-5 and 7 rivets for the rib forward flanges. I put the manufactured heads on the rib flange for all but the most inboard rib. I started out using the long bent stick on the rivet gun to reach around the ribs, but quickly discovered the regular length rivet set would fit if I slightly pushed the rib out of the way and was much easier to control at 50 psi air pressure. I also discovered that the long RV-14 special bucking bar that I used on the elevator was the easiest bucking bar to hold onto for setting these rivets. It takes quite a heavy bucking bar to get these rivets to set before work hardening.

Starting from the inboard side, the top 4 and bottom 2 bolts are oriented with their heads on the spar doubler side to avoid interference with the fuel tank z brackets.

The 4 outboard ribs do not have bolts because the spar cap doubler does not extend that far.

The inboard rib has the torque tube assembly sticking out which made it impossible to get the rivet gun on that side so I put the shop heads on the flange.

Woody did a good job inspecting the bolt ups.

I completed the bolt ups and forward rib flange riveting on the right wing (foreground) and the left wing (background) today.

Section: 14
Hours: 6

With that last batch of priming behind me I was able to get back to riveting today. First up I used the squeezer to attach the flap hinge brackets (2 of 4 ribs shown)

Here are the riveted torque tube support subassemblies.

The rivet holes for attaching the torque tube support to the wing rib were too close to the angle wall to fit the squeezer in so I clamped the rib to the table and used the rivet gun and a bucking bar.

Next I clecoed all the ribs to the spars and then sorted out the AN3 bolts attach bolts by length. The manual details which length bolts go to each rib, but the drawing is very busy. I started with the outboard rib and worked my way in. I did the left and right wings simultaneously to make sure I put the same bolts in the same ribs in the same places on both wings. As I inserted the bolts for each rib, I yellowed out the bolt callout on the drawing to keep track of where I was in the assembly. I finished inserting the bolts for all but the inboard 3 ribs and have the right number and sizes of bolts left. Tomorrow when I'm fresh I'll double check my bolt placements and torque them down.

Section: 14
Hours: 3.5

I primed the ribs and flap support brackets for the left wing.

Section: 14
Hours: 5

I spent the whole day prepping the left wing ribs for priming. I degreased with soap and water and then acid etched and scotch brite scoured 14 ribs and the flap hinge brackets.

Section: 14
Hours: 4

I match drilled the left wing ribs to the spar and drilled the systems holes for the wiring runs.

The instructions in section 14 have you dimple only the lower flange of the ribs, but I know that the upper skins also have flush rivets. I read ahead and discovered that the inboard 4 ribs do not get dimpled because the wing walk doublers and wing skin get counter sunk. However, the remaining ribs do get dimpled. I went ahead and dimpled the upper flange for all but the inner 4 ribs for both the left and right wing now, rather than wait until chapter 16. It is easier to dimple before the ribs are riveted to the spar.

Section: 14
Hours: 4

I drilled the systems holes into the ribs for the right wing and deburred them. The construction manual instructions and drawings for the systems holes didn't add up in the Rev. 1 version. I downloaded the latest Rev.2 drawings and it still wasn't completely clear. I ended up drilling holes for the specified bushings. The number and placement of the holes varies as you move outboard.

Section: 14
Hours: 6

I unwrapped the wing spars, removed the rib bolts, nuts and washers and clecoed the ribs in place. There are three basic ribs forms (W1010,W1011, W1012) and each comes in left and right hand versions.  Not all left hand pieces go into the left wing panel- a mixture of left and right hand pieces go into each wing. It took some very careful reading of the diagrams in the construction manual to get everything in the correct place. I assembled both the left and right wings to make sure I got all the ribs in the correct places. It was a good cross check to do both wings- I did end up with 1 rib mis-sorted which I discovered while assembling the opposite wing.

I match drilled the ribs to the spar for the right wing. I also deburred the just drilled holes.

Section: 14
Hours: 4

I dimpled all the rivet holes in the bottom flange of all the ribs using the pneumatic squeezer (616 dimples).

Next I finished the edges and assembled the torque tube support subassemblies and final drilled and deburred all the holes.

I had to move the flute in the rib slightly off center between the rivet holes to provide clearance for the bracket. I flattened out the original flute, marked the new location and then squeezed another flute.

I finished up this afternoon assembling and drilling the 4 flap hinge assemblies (two shown here). I had already finished the edges and straightened the flap hinge brackets right after unpacking the wing kit back at the end of October, so this task went fairly quickly today.

Section: 14
Hours: 4

Today was fluting day- the forward portion of all the ribs need to be fluted. Here's the tools I use- fluting pliers, flat pliers, triangle and a wood block with slot and rounded nose for bending the flanges.

When the flanges are formed in the factory, they warp slightly as seen in this photo.

Flutes have to be added to the flange to pull the rib back to flat.  There is a real art to fluting- if you flute too deeply, the rib bends in the opposite direction. Each flute needs to be approximately half way between each rivet hole. I've found that you need slightly deeper flutes towards the middle and shallower flutes on the ends of the ribs. In general I make two passes- the first pass I just lightly flute so the rib will come close to lying flat on the table. Then I hold the rib down on the table and adjust each flute until I see the end of the rib lift slightly off the table.

After fluting, I go around and check all the flanges to make sure they are 90 degrees to the table. Often the flanges are slightly splayed outwards and have to be bent back using the wood block shown below. I initially just eyeball the adjustments.

After getting the flanges close to 90 degrees using the wood block, I check all the rivet hole locations to make sure the flange surface is very close using my drafting triangle. I'll make small adjustments using my fingers to get the final alignment.

Here's the stack of 28 ribs with flutes added. Woody is double checking the instruction manual to make sure I didn't miss anything.

Section: 14
Hours: 5

I'm back to working on the wings. Today I worked on finishing the edges of the 28 wing ribs. I ran all the edges over the grinding wheel and used the die grinder to deburr all the interior cutouts. Then I final sized all the flange rivet holes using a #40 reamer in the air drill. The reamer leaves very clean holes, but I still did a de-burr pass after reaming. Each rib has 44 holes so that was 1,232 reams and 2464 de-burrs (one for each side of the hole). Lots of work with little to show other than a big stack of ribs!

Section: 14
Hours: 2

I pulled out the remaining wing ribs and started the work to get them ready for priming. I used my die grinder to smooth out the interior lightening holes.

It's a pretty tall stack of parts and I only made it about a quarter way through them, even with Woody's help. Woody was worried about the grooves that are getting worn into the grinding wheel. Luckily there are a couple more wheels in the bag.