Project: mhlRV14A     -     Entry

Apr 30, 2023 7.8 22-02 - Hinge Bracket and Nose Rib Preparation Category: 22 Ailerons
Initial Prep (Debur, Trim, Drill, and Cut)
4/28/23 - 3.0h
4/29/23 - 1.2h
Preparation of the inboard and outboard hinge brackets started with separating the parts as shown in the plans. I then filed off the tabs at the attachment points and deburred all holes and edges. I checked the holes for proper sizing, and final drilled the holes as necessary.

The ailerons only use 3 nose ribs each (total six), so preparation went pretty quickly. I did not need to flute any of the ribs or adjust the angle of the flanges. I buffed the leading edge flanges of the inboard nose ribs as shown in the plans to reduce the faceted appearance when they are installed in the leading edge skin.
[Band Saw, Hole and Edge Deburring Tools, #12 Drill, #30 Drill, #40 Drill]

Final Prep (Dimple, Countersink, and Shape)
4/29/23 - 1.1h
The inboard and outboard hinge brackets (A-1006-1A and A-1007-1A) are countersunk for the head of AN426AD4 rivets, which attach the brackets to the nose ribs. Each inboard rib also gets a nut plate installed on the web inside the upper rear flange. The plans do not specify countersinking the corresponding nut plate holes in the hinge brackets, but the rivets used for the nut plates are AN426AD3, so countersinks for those rivets are clearly required in addition to the #30 rivets to attach the hinge brackets.

The top and bottom flanges of the ribs are dimpled for the leading edge skins. The reduced diameter dimple die in the pneumatic squeezer did a nice job on the dimples in both the inboard ribs and the much thicker/heavier nose ribs. The nose ribs have two forward flanges, in addition to the top and bottom flanges, where the counterbalance rod is screwed into place. I did not dimple the holes in the forward flanges since they will be upsized later to #27, and there is no need to dimple them to attach the counterbalance rod.
[Pneumatic Squeezer, #40 Reduced Diameter Dimple Dies, Microstop Countersink Cage, #30 Countersink Cutter, #40 Countersink Cutter]

Prime
4/29/23 - 1.1h
4/30/23 - 0.4h
Priming followed my now-standard method of cleaning/scuffing, degreasing, and priming. I did the cleaning before dimpling holes to ensure the holes were completely deburred and to make the cleaning/scuffing step easier. I waited to degrease and prime the parts until after the rib flanges were dimpled.
[Grey Scotchbrite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Rust-Oleum Automotive Self Etching Primer (Green – Rattle Can)]

Assemble
4/30/23 - 1.0h
Assembly of the inboard and outboard hinge brackets/nose ribs went relatively well. The pneumatic squeezer had good access to all the rivets including the AN426AD3-4 rivets for the nut plates on the inboard hinge bracket assembly. I riveted the brackets in place first, and then installed the nut plates as shown in the plans.
[Pneumatic Squeezer, Flush Squeezer Dies]


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