Initial Prep (Debur, Trim, Drill, and Cut) 2/6/23 - 1.6h 2/7/23 - 0.8h 2/18/23 - 3.3h 2/19/23 - 2.9h 2/20/23 - 1.6h 2/21/23 - 1.7h 2/22/23 - 0.5h The first task on this page is to match drill the ADAHRS mounting zee to the left inboard J-channel. The flange of the mounting zee where it attaches to the J-channel is slanted, and there aren't any specifics in the plan on how exactly to match drill the holes. I looked at several builder sites, and didn't get any hints there, either. My main concern was the eventual level installation of the GMU-22 magnetometer on the ADAHRS mounting bracket. In the end, I realized that the leveling would have to come after the wing was attached, and it would likely take some washers to shim the ADAHRS mounting plate to achieve a level installation. I decided to draw a line down the middle of the J-channel, and use that as a guide to match drill the holes. [Hole and Edge Deburring Tools, 12” #30 Drill, Cleco Clamps] Final Prep (Dimple, Countersink, and Shape) 2/9/23 - 0.8h 2/12/23 - 0.6h 2/16/23 - 0.7h 2/20/23 - 3.0h 2/22/23 - 0.3h 2/23/23 - 2.2h 2/24/23 - 3.3h The dimpling description in the previous log mentioned taking a moment to visualize the final build and ensure the dimpling orientation is correct. That applied to this step as well. Dimpling the wing box J-Stiffeners is straight-forward, but the ADAHRS parts needed just a little thought to get things right. The six holes on the bottom of the ADAHRS mounting zee are dimpled inward to mate with the lower wing skin, and the middle three holes on top of the mounting zee are dimpled the opposite direction to mate with the ADAHRS mounting plate. The corresponding center three holes in the mounting plate are also dimpled to fit with the mounting zee. The outer two holes on the mounting plate and mounting zee top are not dimpled, because there is a flat part that mates above those parts. That brings us to what I think is an error in the plans. The plans say the ADAHRS retainers should be countersunk, but those are very thin parts and would be impossible to fully countersink without enlarging the rivet holes. The retainers sit on top of the ADAHRS mounting spacers, which are very thick parts. My solution is to machine countersink the top of the thick spacers to fit the dimpled retainers, dimple the thin retainers to nest with the spacer countersinks, and leave the plate and mounting zee below flat. Several holes are final drilled from the inboard bottom skins to the inboard ribs for nut plates that will eventually be used to connect the wing fairings. The nut plate screw holes are final-drilled #19 as well as the #19 screw hole for the access plate attach locations. The newly drilled holes all need to be deburred after removing the skin from the wing. This step references Section 16 of the plans to modify the lap joint between the inboard and outboard bottom wing skins to be the same thickness as the adjacent leading edge skins. Section 16 says to remove material thickness from the top outboard forward edge of the inboard wing skin and the bottom inboard forward edge of the outboard wing skin to be of equal thickness with the fuel tank skin upon installation. This task is a little easier for the bottom skins since the fuel tank is already installed making it easy to check your progress. I took this opportunity to ensure the leading edges of the inboard and outboard bottom wing skins didn't overlap any of the leading edge skins at the spar. Some light filing and sanding made everything fit properly. Finally, section 16 instructs you to put a slight break in the leading edge of both inboard and outboard top wing skins, and the inboard edge of the outboard top wing skin. There is no instruction in this section to do that for the bottom skins, but I expanded the instruction to modify the lap joints to include putting the same edge break on the bottom skins prior to dimpling the holes. I also planned to modify the bottom left outboard wing skin for my pitot mast. The pitot mast came with location and installation instructions, which I modified to suit my installation. The pitot mast goes just outboard of the rib that is outboard of the bellcrank inspection plate. My mast has a joggle to allow it to attach inside the spar flange with the mast plate on the bottom wing skin. I match drilled the pitot mast joggle to the spar first, and then transition to the skin to cut the hole for the mast. The trickiest part of the installation by far was ensuring everything was aligned before cutting the hole in the skin and match-drilling the top holes. My hole in the skin for the pitot mast isn't perfect, but it is really close, so overall I was happy with the way it turned out. I countersunk the holes in the aft side of the pitot mast plate and dimpled the corresponding holes in the skin. The end result will rivet the mast forward-edge joggle to the skin and spar in 3 places, and rivet the aft portion of the plate to the skin in 2 places. [22” C-Frame with #40 Reduced Diameter, #40 Standard, #30 Standard, and #19 Dimple Dies, #40 Drill, #19 Drill, Micro-Stop Countersink Cage, #30 Countersink Bit, #40 Countersink Bit] Prime 2/8/23 - 1.1h 2/10/23 - 0.8h 2/17/23 - 0.1h 2/22/23 - 1.2h 2/25/23 - 1.5h [Grey Scotchbrite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Rust-Oleum Automotive Self Etching Primer (Green – Rattle Can)] Assemble 2/17/23 - 0.9h The ADAHRS mount assembly is essentially a mini practice project and a lot of fun to put together. I reviewed the assembly steps in the plans, and decided to back-rivet the majority of the parts together. I started with the center 3 rivets that attach the mounting zee to the mounting plate, and then went up a layer to back-rivet the mounting spacers and retainers to the mounting plate. I deviated from the plans by countersinking the mounting spacers dimpling the ADAHRS retainers rather than countersinking the thin retainers. That ended up working very well, and they all came together nicely. I set the final three universal head rivets that attach the latch to the mounting plate with the pneumatic squeezer. It took a second to figure out a good way to clamp the assembly to the workbench before setting the rivets. I started with the center rivet with the holes on either side cleco'd, which worked fine. I had a little trouble getting a tight fit between the parts on the 2 outer rivets since there was nothing on the outer side to hold the parts together. I partially setting the rivets and noticed a small gap between the parts. I squeezed the parts back together using a nylon spacer with a hole slightly larger than the shop head of the rivets. The partially set rivets held the parts tightly together while I finished the final squeeze. I wasn't sure that method would work, but decided to try it on a non-structural part that could be easily replaced if things went bad. The experiment ended up working really well, and I'll keep it in mind if I run across similar situations down the road. [3x Rivet Gun, Back-Rivet Set, Back-Rivet Plate, Pneumatic Squeezer, 1/4" Cupped Rivet Set]