Section 15 – Outboard Leading Edge

Now that I’ve got some workbench space again I started working on the leading edge. First step was to cut a couple of cradle V-blocks out of plywood to hold the leading edge skins while riveting.

Next it’s time to work on ribs again. So back to the same routine as earlier: drill holes to final size, debur both sides of the hole, debur the edges as well as the lightening holes, straighten the flanges so they’re 90 degrees to the rib web, then flute the rib flanges so the rib is straight. That took about 8 hours over Friday, and Saturday.
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I snuck out for a few hours on Easter Sunday and worked on polishing the nose portion of the ribs on the scothchbrite wheel so that the bent tabs are more rounded than faceted. Then I started dimpling. Here’s Ashley doing a bit of dimpling on the DRDT-2. More dimpling later.
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Section 12 – Riveting the Ribs to the Main Spar

Over the past two days, I finished section 12 of the instructions. I started off by assembling the Flap Brackets on the 3rd and 8th ribs as well as the torque tube bracket on the 1st most inboard rib. I then clecoed all of the ribs back onto the spar and torqued the AN3 bolts to the prescribed 28 inch-lbs. Finally, I riveted the ribs to the spar.
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Section 12 – Assembling and Match Drilling Ribs

Today I assembled the flap brackets and match drilled the #30 holes. During this I noticed that one of the W-1025A brackets has a fairly deep gouge in it, apparently a product of the drilling operation at the factory. See the picture below
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I have sent these pictures to Van’s to ask if this should be polished out or if it needs to be replaced.

Next I mounted the ribs on the spar and match drilled the 30 and 40 sized holes in the rib flanges with the spar. I marked and disassembled the ribs from the spar for priming. I started off using SEM Self Etching Primer but ran out. I then used Nappa 7220 primer which is about 1/3 the cost of SEM but doesn’t go on nearly as smoothly. I may try another brand tomorrow.
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Section 12 – Dimpling the Ribs

Finished up deburring the 40 sized holes on the upper and lower flanges of the wing ribs today. After deburring all of the holes, each one was dimpled. I couldn’t use the DRDT-2 for the dimpling of the ribs so I used the hand squeezer. I mounted it to the workbench so I could hold the rib with one hand and dimple with the other.
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So for each of 28 ribs, I have now:

  1. deburred the edges
  2. fluted the flanges to straighten the rib
  3. final drilled the holes in the flange (around 45 per rib)
  4. deburred the hole
  5. dimpled the hole

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Section 12 Wing Ribs Part III

Third day of working on wing Ribs. Lots of deburring and fluting. Below you can see a completed wing rib with the flutes in the flange. These are done to effectively shorten the flange and pull the rib straight. It gets warped by the manufacturing process and this is the method to straighten it.
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Additionally, every edge has to be deburred which consists of running either a deburring tool, or a grinding wheel over the edge and then polishing it with a polishing pad. This includes the insides of the lightening holes. 20 completed, 8 to go.
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Section 12 Wing Ribs

Started work on Section 12 yesterday. Started by building a fixture on the workbench to hold the Spar upright on the workbenches. Then separated and deburred and primed all of the various W-1029 parts. I then started deburring the wing ribs. This will be followed by fluting to make sure they’re straight.

And just to show how exciting all this work can be… here’s a time lapse