While it appears I am jumping around in several wing sections of the plans, I am doing this because it allows me to make more efficient use of my time while getting help with riveting wing top skins, as my daughter (helper) is also busy with school and other activities. School will end soon for the summer break though, so that should allow me to finish up the top wings skins shortly after.
In the meantime, I jumped into working on flaps, and after gathering all the parts mentioned in the plans, I started by checking that all rib flanges were at 90 deg. to the web.
 |
| A pile of flap internal parts |
While working on adjusting the flanges of the nose ribs, I noticed that there is a flange on each rib that has no holes but is pushed outward (like a reverse flute) in the center. Checking the plans, I see that two holes will be match drilled into this flange later, so for now I decided to debur the edges of the nose ribs and flute the center of this flange properly. This makes it easier to adjust the flange to 90 deg and will provide for a better fit to the nose skin.
 |
| Notice the small outward bend in the undrilled flange of this nose rib |
 |
| Using fluting pliers to reverse the bend in the flange. The flute was placed in the center of the flange as there will be two holes match drilled on either side of the flute into this flange later |
 |
| Flange after fluting and adjustment to 90 degrees |
Another issue I found while deburring the nose ribs was a small crack in one end of the flange (at the relief notch) that attaches to the flap spar. I saw this on two of the nose ribs. These must have happened during forming of the nose ribs, but I am not sure why, especially as these are punched parts. The two cracks were, however, small enough to easily file out while maintaining hole edge distance so no part replacement was necessary. I also inspected all other flap parts thoroughly for any other cracks, but did not find any.
 |
| Small crack in flange bend that one end of the flange that connects the nose rib to the flap spar |
 |
Crack removed after filing and deburring (in the same nose rib as pictured above)
|
Next I started working on the FL-1007 Left and Right hinge brackets. After deburring all edges, the plans have you take 3 left hinge brackets (for the left flap) and mark and drill four #40 holes in each at a specified spacing. I did this for the 3 left hinge brackets, and also for 3 right hinge brackets (for the right flap) since the right flap is a mirror image of the left
 |
| Drilling holes in the joggled portion of the hinge bracket. Holes were first drilled with a 3/32" bit followed by a #40 reamer |
 |
All hinge bracket joggle holes drilled and deburred. These will be match drilled to opposing hinge brackets later in the section.
I then got the flap skins out of storage and deburred all edges. I was able to adjust the flanges of the inboard ribs to match the skin edge, since the inboard ribs attach at an angle.
|
 |
| Bending the inboard main rib flange to be parallel with the bottom flap skin edge |
Next I worked on the rod end rib and hinge pair rib subassemblies, being careful to mirror the left flap assemblies when working on the right flap assemblies.
 |
| Drilling the 1/4" bolt holes in the inboard and outboard rod end rib subassemblies |
 |
| Countersinking the nutplate holes in the outboard rod end rib subassembly |
 |
| Left and right flap rod end rib subassemblies with all web holes drilled and deburred |
 |
Left and right hinge pair rib subassemblies labeled and deburred
I then decided to tackle trimming the tab off the aft end of each main rib. I was able to trim off the majority of the tab by carefully using the band saw to follow a marked line on the rib. Next I used a Dremel sanding drum along with a needle file to clean up the cut and trim away material down to the line. I was happy with how this worked out, although it took a little time as there are 22 ribs to be trimmed this way.
|
 |
| Using the band saw to trim away most of the rib tab at the trailing edge |
 |
| I had to be careful to hold the rib steady and angle it up to cut away the tab so that the opposite side of the rib would not get cut by the saw |
 |
| Sanding the tab down to the marked line using a 1/4" drum sander |
 |
| Cleaning up the trimmed edge using a medium needle file. |
 |
| Stack of trimmed ribs seen trailing end on |
 |
| Ribs trimmed and deburred down to the notch |
I also worked on the center hinge sub assemblies. The assembly of these starts with taking the four FL-1008 spacers and ensuring they are all flat. The spacers are each 1/8" thick, but it turns out they were all perfectly flat as they came in the kit, so I had nothing to do there.
The plans also give the option of drilling lightening holes in the spacers. I decided to give it a go and marked the hole locations on one of the spacers. For my first attempt, I drilled holes slight smaller that the specified 1" and 1/2" sizes using a step drill, and then cleaned up the holes using a file and Dremel drum sander. While this worked, and gave me almost round holes after filing, it took a long time to sand away the extra material.
For the remaining 3 spacers, I decided to purchase
1" and
1/2" hole saws on Amazon. These worked well in the drill press, but I noticed that after drilling the 1" holes, they were each slightly larger than 1", so to maintain adequate spacing between the lightening holes, I decided to drill the other two holes at 1/4" diameter rather than 1/2" diameter. All holes turned out nicely with less mess than my first attempt (although still a lot of shavings to clean up).
You may ask how much weight reduction resulted from drilling these lightening holes. Well, prior to drilling, each spacer weighed exactly 40g. After drilling the 3 lightening holes, the weight dropped to around 34.5g, so a whopping 5.5g from each spacer, or about 22g total. Not really that much! If I had to do it over, I probably wouldn't bother drilling the lightening holes, and the time taken and cleanup required outweighs the benefit of the weight reduction.
 |
| Lightening holes marked on the FL-1008 spacer at the required positions |
 |
| Holes were drilled using the 1" hole saw pictured. The 1/4" holes (in lieu of 1/2" holes) were drilled using a regular drill bit and 1/4" reamer |
I then assembled and labeled the parts of the left and right center hinge subassemblies.
 |
| Left and right center hinge subassemblies ready for fitting to the flap spars and skins |
Dates: May 26 - June 16 2024
Wing Flap Total Time: 17.4 hours
RV-10 Build Total Time: 719.1 hours
Priming Total Time: 83.6 hours (not included in build time totals)
