Rudder Complete!

What a surge of motivation yesterday when we got to see a real, flying RV-10 and speak to its builder for hours! We were able to make quick work of the trailing and leading edges of the rudder, letting us check this box off just one day after checking off the HS!

Rolling the leading edge skin with duct tape and some 1.25" PVC pipe

Sarah setting the pop rivets into the leading edge... it was a little tricky applying just the right pressure to not have the ends of the skin bow either in or out.

The trailing edge after riveting: we used the same technique as on the trim tab, and I'm very pleased with the results!

The rudder with the trim tab installed: the rivet pattern matches up, and everything looks very straight!

Only two parts remain in the empennage: the elevator and the tailcone! We're both so pleased and excited with the progress we've made so far, but there is LOTS more to do... stay tuned for tomorrow, when we'll begin on the elevator!

Horizontal Stabilizer Complete!

A few short hours later, and I was rewarded with the completion of the biggest part yet on this journey! It's really incredible how strong (and light) the HS feels once it's all together, especially after feeling how flimsy all the pieces are by themselves... it truly is a real-life example of a whole being more than the sum of its parts...

The completed HS, right side.

The completed HS, left side.

Today was also a pretty exciting day because I got to see a real live RV-10 up close! Our local EAA chapter's flight advisor, Dave, who has a remarkably long list of accolades as both a pilot and a flight instructor... just so happens to have built one himself, and regards it as his favorite airplane. He was kind enough to invite Sarah and I up to his hangar and give us a full walkthrough... along with opinions, advice, and words of encouragement. Hopefully sometime soon we'll have a chance to go flying in it! For now, here's happy Mike sitting in the same model of plane he is building, for the first time:

Horizontal Stabilizer Assembly

Wow there are a lot of rivets on this part! The dimpler got a good workout today, that's for sure:

The homemade C-frame dimpler in action

After dimpling the skins and prepping the rest of the parts, it was time to begin actually assembling the HS.

The skins set in their cradles, ready for final riveting and assembly

The nose ribs, riveted into the skins.

First, the nose ribs were riveted to the skins, after which the whole front spar, rib, and stringer assembly went in as one part. A few hundred rivets and many hours later, I had about half of the HS assembled. Dinner plans with friends brought the day to a close, which was probably good since I was starting to get very tired of the monotony of the whole riveting process!

HS Front Spar Assembly

As promised, work continued today on the HS. I finished priming the parts for the front spar and ribs, and began assembling the front spar. This included riveting the main attachment brackets to the doubler and spar with a healthy number of rivets... this thing has to be strong, and what do you know, it is!

The HS front spar, just after riveting

The spar, doubler, and attachment brackets, laid over the instructions calling out the appropriate rivets.

That's all for now... next thing will be to assemble the ribs to the stringers and start putting the whole assembly together!

HS Rear Spar/Trim Tab Work

A lot of the project is on hold until the first coating of primer that I applied yesterday has had 48 hours to cure so I can finish the job. However, the HS Rear Spar was already fully primed and could be assembled, so I focused on that. I riveted it and its parts together per the plans in sections 8-2 and 8-3. I also added two grounding nutplates near the number 2 and 4 elevator hinges, in case I want to add static wicks in the future.

 The #2 elevator hinge bracket, with the grounding nutplate just inboard of it.

 The #4 elevator hinge bracket, mirror image of what was done to the #2 bracket above.

 

The #3 (center) elevator hinge, with all rivets holding the doubler in place shown here.

The other side of the HS Rear Spar, with the hinge bolts torqued properly into place.

While waiting for things to do on the HS, I turned my attention briefly to the rudder. The proseal had cured enough to move on to riveting, and I thought it would be best to rivet the trim tab trailing edge first, since if I messed that up it would be easier than redoing the whole rudder! I had the rivets alternate directions to make things more even (probably for appearance more than anything) but I think it did help it stay straight too. There are a lot of posts online that warn builders of this step, so I was going pretty cautiously... It actually turned out to be a lot of nervousness over nothing, it went together very easily thankfully!

The rudder trim tab, with the trailing edge riveted together.

I'm not sure if the picture does it justice-- looking at it now, it appears to be a little wavy, but it actually came out very straight. There is one spot near the bottom corner that we'll need to fill in slightly though, because the corner got rounded off too much on one side, but I'm pretty confident it won't be that big of a deal. I'll see if I can take a better picture of it once it's all assembled together.

Sarah found the mother load of primer across town today, and so we bought 6 more cans... hopefully that should be enough for the rest of the empennage! Now we wait until tomorrow to finish priming and then begin the final assembly of the horizontal stabilizer.

Horizontal Stabilizer - Day 4

Tonight was a fun night! We continued onto section 8-9, adding the stringers and rear spar to the HS assembly, and clecoing the entire skin into place. Now comes the fun task of final-drilling every single hole in the skin, through any combination of ribs, stringers, and spars. Sarah and I decided to split sides and each work either the top or bottom skin. First, though, we needed to figure out which drill was the lightest one so that Sarah could use it ;-)

Ergonomics [and Chivalry] 101: Sarah determines which DeWalt 14.4V drill is lighter using the epoxy-mixing/postage scale.

After an arduous drill-usage negotiation, I took my 2.1kg drill to the bottom skin while Sarah took her 1.8kg drill to the top skin, and we spent the next several hours final-drilling every hole in the horizontal stabilizer. Just as drilling was coming to a close, our friend Brannen stopped by to watch and help with the process. After disassembly, all the holes needed to be deburred and then dimpled, which everyone including our dog Mesa was happy to watch:

Everyone, even the dog, was told to act serious while Mike works.

The dimpling process is getting pretty familiar by now. I've learned that putting one handle of the squeezer into a vice makes it a lot easier to run it through each hole in each part in the least amount of time. An hour or two of dimpling later, and it was prime time!

The HS bits, 97% primed

Unfortunately, I ran out of primer around midnight. This mostly affected the HS front spar, but many of the parts could have used a little more attention to the corners, etc. I quickly hopped over to Walmart (dressed to the 9's, of course) in the hopes that they would have some more in stock, but alas they were still out from the last time I had checked a couple weeks ago. This means that I'll have to wait two days before priming again, since the instructions say that additional coats must be applied within 1 hour or after 48 hours. Time to call it a night!

Horizontal Stabilizer - Day 3

Made it through almost 4 pages of the plans today! While yesterday dealt with parts going on the HS rear spar, today was all about the HS front spar. I started by making the HS-1013, HS-1014, and HS-1015 spar caps and stringers out of their raw materials:

Starting Section 8-4

The familiar process of measuring, measuring again, cutting, coarse sanding, coarse filing, and fine filing began. Sarah was away today, flying to KPRO (Perry, IA) in a Cardinal with some friends to attend a meeting with (and join) the 99's. Super excited for her, and jealous that she got to ride in a Cardinal :-)! In her absence, my friend Roy stopped over and helped keep me company with the fabrication process. The spar caps then needed to be clamped into the HS front spar and match-drilled to the specified holes. About 4 hours later (including a quick trip to Sears to buy more 3/32" drill bits), I had these parts in front of me:

At this point, we were in the middle of section 8-5, which called for the temporary assembly of the HS front spar, doubler, caps, and HS attachment brackets. I got a kick out of the fact that the plans called out to use "something flat" to align the brackets square against the spar.

The plans for temporarily assembling the HS front spar components

My "something flat" was a scrap 1"x1" piece of square metal stock, left over from when I built my C-frame dimpling tool.

It turns out that a total of nine holes are necessary to rivet these brackets to the front spar (only 4 had been drilled when the above photo was taken). Needless to say, the drilling process had my full attention! Anyway, some time later I had completed everything in this section except for the riveting portion, and was able to move on to the ribs in section 8-6 thru 8-8.

Even though Sarah was away today, I still need to give her credit on this step, since in anticipation for this section she had already unwrapped and deburred all of the HS-1004, HS-904, and HS-905 ribs a few days ago during some downtime, allowing me to blast right through an otherwise lengthy and tedious deburring task. All that still needed to be done was cut out the special parts of four of the center ribs, bend the flanges to spec, and then make some wooden cradles to hold the HS upright as it is assembled. A short while later, I had the HS skeleton clecoed together, along with the skins set in place in their cradles:

The HS skeleton, next to the R and L skins set in their new cradles.

Today ended with clecoing the skeleton to the inside of the skins. Now for the first time, we have something that looks like a horizontal stabilizer!

Last pic of the day: End of section 8-8, step 8!

Horizontal Stabilizer - Day 2

Spent some time up at KIIB today to attend a free ground school they held on weather. We had a great time hanging out with everyone up there as always, grabbed some lunch and didn't make it back until well into the evening so today was another relatively short day of work... but made some pretty cool parts! Since I am skipping the riveting steps for now to save them for later, I moved on to Section 8-3, assembling the inboard elevator hinge and fabricating the front spar attachment brackets out of raw angle aluminum. These brackets took several hours to make, and I have to say I'm pretty proud of the result!

The spec for the HS-1008 brackets

HS-811 Inboard Hinge, and HS-1008-R/L Brackets

Fabricating the two attachment brackets paved new ground for me, for sure. As I started on this step, I wasn't quite certain what part I was actually making, or what it would eventually be used for. However, it seemed that the thickness of the angle aluminum (AA6-187 x 2" x 2.5") combined with the exacting tolerances (to the 1/32nd of an inch!) specified in the plans meant that this must be a pretty important part. The realization slowly started to sink in, oh yeah, these are the two brackets that will attach the HS to the rest of the plane... don't mess these up! With some slow and careful measurements/cutting, combined with a lot more patience than I usually exhibit with small 2 square inch parts, I think they ended up coming out pretty darn close to spec. :-) Oh yeah, also, it turns out aluminum makes a great heatsink! Cutting these with the bandsaw resulted in some pretty toasty parts at times-- the word "yeeeeow!" may have been heard once or twice in the garage tonight...

Rudder Delay - Starting on the Horizontal Stabilizer

Indeed yesterday was one of the most perfect days to fly yet this year. We took the 172 up for a few hours, visited some friends up at KIIB and did some t&g's to try and brush some of the winter rust off... I haven't flown nearly enough these past couple months. It felt great to be in the air on such a beautiful day though, it reminded me why I'm doing this project in the first place!

I started out today by inspecting the Proseal on the rudder since it's been two days, only to discover it was still quite wet. This concerned me at first, but then I went online and did some research to discover the stuff I had bought from Aircraft Spruce was actually of the "B2" classification (see this helpful link) and needed at least 4.5 days to cure in ideal conditions (not two as mentioned in Van's plans). Anecdotally, there are a number of posts online that indicate it can sometimes take a lot longer if the temperatures aren't warm enough, and since it's been fairly cool/cold here in the garage when the furnace isn't on, it will likely need even longer than specified. So I re-clamped the whole thing back together and brought it all down into the basement where it's out of the way and warmer than the garage. Looks like I'll be giving it at least a week or so down there to make sure it's cured... so in the meantime, on to the Horizontal Stabilizer!

No pictures from today-- lots of deburring/prep work but no real visible progress worth taking pictures of. Finished section 8-2 steps 1-4, which was mostly just the initial prep work on the HS rear spar and doubler: match-drilling, countersinking, and deburring as specified. I plan on holding off on the riveting portions for now, so that I can assemble a pile of parts to scuff, acetone, and prime all in one sitting. Lots more to do on the HS!

Joining Rudder Skins

Tonight was an exciting night! We started the night by finishing the remaining work needed for the rudder trim tab: attaching nutplates for the inspection plate, and cutting a C-shaped notch out of the R rudder skin to provide room for the control horn and servo linkage. The resulting internals look similar to what they looked like last night, but now the rudder is finally ready to continue with the assembly process:

Next came the fun part... mixing up some Proseal and riveting the two rudder skins together! From all the posts I've read online about this stuff, I can truly say I was 100% prepared to deal with it, and it really wasn't as bad as I was expecting. I put a light coat on the trailing edge of the L rudder skin, added the wedge, and then put another coat on the wedge. I used a popsicle stick to spread it out evenly across the surfaces, and I don't think I made too terribly big of a mess. Any mess that I did make seemed to clean up pretty easily with acetone. While the Proseal was drying, we had to quickly rivet the internal structure of the rudder together using pop rivets. My friends Brannen and Becca were visiting, and took these pics of the process:

Putting the pop rivets into place in one of the stiffeners.

Setting the rivets using the pneumatic gun.

Finishing up the closing of the rudder.

The rudder, just after riveting the stiffeners together but before clecoing and weighting the trailing edge.

Now, we wait! After this last pic was taken, we clecoed the trailing edge together and placed weighted boards (and a whole line of clothes pins) along the edge to hold it in place. The Proseal now needs two days to cure, after which we'll rivet the trailing edge together and finish the rest of the rudder! In the meantime, we might start on the HS, but we'll see how things go... the weather is supposed to be nice tomorrow, maybe we'll go flying instead :-)

More Rudder Trim Tab

Today I think I mostly finished the rudder trim tab. I added a stiffener to the control horn and left skin of the tab, visible in the picture below. That took most of the time for the night, but then I also added in the trim servo and measured how long the linkage would need to be:

The rudder trim tab with the inside still visible, screwed into the L skin, with the servo and linkage set in their approximate places.

The servo seems to work perfectly with this setup! I also cut the opening for the inspection panel and riveted in the doubler plate. Tomorrow, I think I'll have my "off the map" rudder work done and be able to get back to the manual!

Rudder Trim Tab

Today was a long (but fun!) day, just building one relatively small part that isn't in the basic plans. I wanted to add rudder trim capability since it seems like a pretty popular option, and should make cruise flight easier and more efficient. I've also seen a number of people retrofit their flying -10's with a rudder trim system, which tells me it's worth the hassle.

The project started with determining the proper size and location for the tab. After some researching online, I ended up with a desired tab size of 7" x 2.375" x 3.75" to be placed between the stiffeners in the same section as the center attach point:

It took a few tries to get the lines just where I wanted them, but that's why we draw with a marker instead of a saw :-)

Once the lines were sketched out, I clecoed both skins together with the outer surfaces touching in order to produce both cuts at the same time. I put a "reinforced" cut-off wheel on the Dremel tool, and went to work on cutting. A little while later, I had these this:

The two rudder skins after cutting and deburring

The area the trim tab will fit into. It is approximately 0.5" tall at the top and 0.75" tall at the bottom.

Next, I went to work on building the tab itself. I decided early on that I didn't want to reuse the scrap pieces that I had cut out from the rudder, but instead use new 0.016" sheet aluminum so that I could roll the edges around and make a piece that looks continuous. Figuring out the geometry of the whole deal took quite some time, but I ended up with a design that only will only have one line of rivets holding the whole piece together (other than the trailing edge):

The resulting part actually came out just about exactly as I had envisioned! The control horn *almost* fits completely inside the rudder, but it does bump into the skin just a little bit on its way from side to side. Still better than protruding any significant amount, which is what I first thought I'd have to deal with. I think all I'll need to do is cut a small C-shaped notch out of the opening in the rudder and that should solve the problem-- then I won't even need to use the Avery fairings I bought.

The tab seems to have more than enough travel in both directions, and with the control horn's geometry, it will require about 1" to go from stop to stop, slightly favoring the left side (for right rudder). Since the T2-7A Servo has 0.7" of travel, I think this will work out perfectly and I should be able to adjust the linkage to work as needed.

That's it for now... I'm wanting to finish the tab and servo mechanism before riveting the skins together, but it appears that aside from that, the rudder is getting close to being complete!

Vertical Stabilizer Complete!

A few more rivets, and before I knew it the first part of the build is complete! Feels great to be able to check this box, but after a short break running around the garage holding this thing up like a flag and making airplane noises (I wish I was kidding), back to work!

Actually tonight was a pretty short night building. I used my back-riveting plate for the first time, and back-riveted the skins to the rudder. It worked great! It was pretty quick work, but made it look like a lot of progress!

Both R and L rudder skins, after back-riveting the stiffeners into place

I think the next step before I actually assemble the two halves is to figure out exactly what I'm going to do with the rudder trim tab. A few of the parts came today (including the ProSeal for the trailing edge), so I should be able to start on this endeavor tomorrow. That's all for now!

Empennage - More Rudder/VS Work

Started the evening by running my conduit line through the VS skeleton and fabricating two small brackets to hold the conduit in place between the lightening holes of the VS nose ribs. I forgot to take a picture of them, but they came out pretty good! This conduit will allow me to run lighting and/or antenna wires up to the top fairing of the VS if need be. I also installed a doubler in the top rib of the VS where the conduit terminates to strengthen that area. I primed all the newly made parts and riveted them all into place. The final thing I did to the VS before putting on the skin was to install a grounding nut plate, in case I decide to add static wicks (still undecided on that).

Next was the rudder. We got through the first 4 or 5 riveting steps in section 7, up to the back-riveting of the rudder skins. I'm saving that until after we get completely done with the VS, which is looking like it should be tomorrow. The rudder pieces went together fairly well, and we also added the grounding nut plate in about the same position of the rudder spar. The end of tonight's work on the rudder brought us here:

Sarah getting some more experience bucking rivets... she's doing great!

The control horn/bottom rib riveted together, and rudder spar with doublers and nut plates installed. Looking good so far!

The last thing I did tonight was start work on attaching the VS skin. I had been putting this task off because I wanted to make sure I had done everything I needed to before buttoning it up. After installing the conduit, redoing two of the rivets, and putting in the nut plate, it was ready to be closed in forever! I only got about halfway through it tonight, but I think it was the harder half with all those rivets near the leading edge that were kinda hard to get to with the bucking bar. I got all the rivets forward of the front spar done, as well as all the front spar rivets on one side. It looks like the rest should go pretty quickly tomorrow, and then I'll have my first completed part! Excited for that...

The current state of the VS. All leading edge rivets are complete, and one side's front spar is done (the side not visible).

View inside the leading edge of the VS, with the lower half of rivets complete. You can also see the conduit run going through the lightening holes.

Inside the VS looking forward, you can see the lower half has been riveted to the spar, and the conduit running through the front area.

The grounding nut plate, installed just above the middle hinge on the VS main spar.

The grounding nutplate, installed above the middle attach point on the rudder spar.